,transcrib]'s ,note3 ,! illu/rations h be5 includ$ ) ano!r v]sion ( ?is "w4 ,! image files h be5 nam$ 9 a /raight=w>d mann] t corresponds to ! numb]+ 9 ! text2 ?us1 ,illu/ration #g is includ$ z file fig#jjg4png1 :ile ,illu/ration 7,a7 #bb is includ$ z file fig#jbb;a4png4 ,,! ,,radio ,,amateur',s ,,h& ,,book ,illu/ration3 ,a4 ,fr$]ick ,coll9s1 ,inv5tor ( ! ,wireless ,telephone1 #ahii4 ,aw>d$ ,gold ,m$al = same1 ,alaska ,yukon ,pacific ,exposition1 #aiji4 ,,! ,,radio ,,amateur',s ,,h& ,,book ,a ,complete1 ,au!ntic & ,in=mative ,"w on ,wireless ,telegraphy & ,telephony ,,by ,a4 ,,fr$]ick ,,coll9s ,inv5tor ( ! ,wireless ,telephone #ahii2 ,hi/orian ( ,wireless #aija-aiaj2 ,au?or ( ,wireless ,telegraphy #aije ,,to ,,william ,,m>coni ,,inv5tor ,,( ,,! ,,wireless ,,telegraph ,,introduction ,be=e delv+ into ! my/]ies ( receiv+ & s5d+ messages )\t wires1 a ^w z to ! hi/ory ( ! art & its pres5t day applications may be ( s]vice4 ,:ile popul> int]e/ 9 ! subject has gone =w>d by leaps & b\nds )9 ! la/ two or ?ree ye>s1 x has be5 a matt] ( sci5tific exp]im5t = m ?an a qu>t] ( a c5tury4 ,! wireless telegraph 0 inv5t$ by ,william ,m>coni1 at ,bologna1 ,italy1 9 #ahif1 & 9 8 fir/ exp]im5ts he s5t dot & da% signals to a di/ance ( #bjj or #cjj feet4 ,! wireless telephone 0 inv5t$ by ! au?or ( ?is book at ,n>b]?1 ,p5n41 9 #ahii1 & 9 8 fir/ exp]im5ts ! human voice 0 transmitt$ to a di/ance ( ?ree blocks4 ,! fir/ vital exp]im5ts t l$ up to ! inv5tion ( ! wireless telegraph 7 made by ,he9ri* ,h]tz1 ( ,g]many1 9 #ahhh :5 he %[$ t ! sp>k ( an induction coil set up electric oscillations 9 an op5 circuit1 & t ! en]gy ( ^! waves 01 9 turn1 s5t out 9 ! =m ( electric waves4 ,he also %[$ h[ !y c\ld be receiv$ at a di/ance by means ( a r+ detector1 :i* he call$ a resonator ,9 #ahij1 ,edw>d ,branly1 ( ,france1 %[$ t metal fil+s 9 a tube coh]$ :5 electric waves act$ on !m1 & ?is device he t]m$ a radio conductor2 ?is 0 improv$ ^u by ,sir ,oliv] ,lodge1 :o call$ x a coh]]4 ,9 #ahie1 ,alex&] ,pop(f1 ( ,russia1 con/ruct$ a receiv+ set = ! /udy ( atmosph]ic electricity1 & ?is arrangem5t 0 ! e>lie/ on record ( ! use ( a detector connect$ ) an a]ial & ! e>?4 ,m>coni 0 ! fir/ to connect an a]ial to "o side ( a sp>k gap & a gr\nd to ! o!r side ( x4 ,he us$ an induction coil to en]gize ! sp>k gap1 & a telegraph key 9 ! prim>y circuit to break up ! curr5t into signals4 ,add+ a ,morse regi/]1 :i* pr9t$ ! dot & da% messages on a tape1 to ! ,pop(f receptor he produc$ ! fir/ sy/em = s5d+ & receiv+ wireless telegraph messages4 ,illu/ration3 ,coll9s' ,wireless ,telephone ,exhibit$ at ! ,madison ,squ>e ,g>d51 ,octob] #aijh4 ,aft] ,m>coni _h %[n ! _w h[ to telegraph )\t connect+ wires x w\ld seem1 on fir/ ?\ght1 to be an easy matt] to telephone )\t wires1 b n s1 = ! electric sp>k sets up damp$ & p]iodic oscillations & ^! _c be us$ = transmitt+ spee*4 ,in/ead1 ! oscillations mu/ be ( con/ant amplitude & cont9u\s4 ,t a direct curr5t arc light trans=ms a "p ( its en]gy into electric oscillations 0 %[n by ,fir? & ,rog]s1 ( ,engl&1 9 #ahic4 ,! au?or 0 ! fir/ to connect an arc lamp ) an a]ial & a gr\nd1 & to use a microphone transmitt] to modulate ! su/a9$ oscillations s set up4 ,! receiv+ app>atus consi/$ ( a v>iable contact1 kn[n z a pill-box detector1 :i* ,sir ,oliv] ,lodge _h devis$1 & to ?is 0 connect$ an ,ericsson telephone receiv]1 !n ! mo/ s5sitive made4 ,a lat] improvem5t = sett+ up su/a9$ oscillations 0 ! au?or's rotat+ oscillation arc4 ,s9ce ^? memorable days ( m ?an two decades ago1 wond]ful advances h be5 made 9 bo? ( ^! me?ods ( transmitt+ intellig5ce1 & ! end is z yet n[h]e 9 sight4 ,twelve or fifte5 ye>s ago ! boys began to get fun out ( li/5+-9 to :at ! %ip & %ore /ations 7 s5d+ &1 fur!r1 !y began to d a little s5d+ on _! own acc\nt4 ,^! y\ng/]s1 :o caus$ ! pr(essional op]ators _m a pang1 7 ! fir/ wireless amateurs1 & among !m exp]ts 7 develop$ :o are =emo/ 9 ! practice ( ! art today4 ,away back !re1 ! sp>k coil & ! arc lamp 7 ! only kn[n means = sett+ up oscillations at ! s5d+ end1 :ile ! electrolytic & cry/al detectors 7 ! only available means = ! amateur to receive !m4 ,z x 0 next to impossible = a boy to get a curr5t hav+ a high en\gh voltage = op]at+ an oscillation arc lamp1 wireless telephony 0 out ( ! "q = him1 s he _h to /ick to ! sp>k coil transmitt] :i* ne$$ only a batt]y curr5t to en]gize x1 & ?is1 ( c\rse1 limit$ him to s5d+ ,morse signals4 ,z ! electrolytic detector 0 cumb]some & requir$ a liquid1 ! cry/al detector :i* came into be+ %ortly aft] 0 j z s5sitive & soon displac$ ! =m]1 ev5 z ?is _h displac$ ! coh]]4 ,a few ye>s ahead ( ^! amateurs1 t is to say 9 #aije1 ,j4 ,a4 ,flem+1 ( ,engl&1 inv5t$ ! vacuum tube detector1 b t5 m ye>s elaps$ be=e x 0 p]fect$ to a po9t :]e x c\ld compete ) ! cry/al detector4 ,!n its use became g5]al & work]s ev]y:]e s\ght to1 & did improve x4 ,fur!r1 !y f\nd t ! vacuum tube w\ld n only act z a detector1 b t if en]giz$ by a direct curr5t ( high voltage x w\ld set up su/a9$ oscillations l ! arc lamp1 & ! value ( su/a9$ oscillations = wireless telegraphy z well z wireless telephony _h already be5 discov]$4 ,! fact t ! vacuum tube oscillator requires no adju/m5t ( its elem5ts1 t its initial co/ is mu* less ?an ! oscillation arc1 besides o!r consid]ations1 is ! reason t x popul>iz$ wireless telephony2 & because cont9u\s waves h _m advantages ov] p]iodic oscillations is ! reason ! vacuum tube oscillator is replac+ ! sp>k coil z a wireless telegraph transmitt]4 ,moreov]1 by us+ a numb] ( l>ge tubes 9 p>allel1 p[]ful oscillations c be set up &1 h5ce1 ! waves s5t out are radiat$ to enorm\s di/ances4 ,:ile oscillator tubes 7 be+ exp]im5t$ ) 9 ! rese>* laboratories ( ! ,g5]al ,electric1 ! ,we/+h\se1 ! ,radio ,corporation ( ,am]ica1 & o!r big companies1 all ! y\?ful amateurs 9 ! c\ntry _h le>n$ t by us+ a vacuum tube z a detector !y c\ld easily get messages #ejj miles away4 ,! use ( ^! tubes z amplifi]s also made x possible to employ a l\d speak]1 s t a room1 a hall1 or an out-(-door audi5ce c\ld he> cle>ly & di/9ctly ev]y?+ t 0 be+ s5t out4 ,! boy amateur _h only to let fa!r or "m li/5-91 & !y 7 duly impress$ :5 he told !m !y 7 gett+ x f ,,kdka 7! ,pittsburgh /ation ( ! ,we/+h\se ,co471 = 0 n ,pittsburgh #ejj miles away6 ,& s !y1 too1 became en?usia/ic wireless amateurs4 ,?is new int]e/ ( ! gr[n-ups 0 at once met n only by ! manufactur]s ( app>atus ) complete receiv+ & s5d+ sets1 b also by ! big companies :i* began broadca/+ regul> programs consi/+ ( music & talks on all sorts ( int]e/+ subjects4 ,?is is ! wireless1 or radio1 z ! av]age amateur kn[s x today4 ,b x is by no means ! limit ( its possibilities4 ,on ! contr>y1 we are j beg9n+ to realize :at x may mean to ! human race4 ,! ,gov]nm5t is n[ utiliz+ x to s5d out wea!r1 crop & m>ket reports4 ,=eign trade conditions are be+ report$4 ,! ,naval ,obs]vatory at ,arl+ton is wireless+ "t signals4 ,dep>tm5t /ores are beg9n+ to issue programs & adv]tise by radio6 ,cities are also tak+ up su* programs1 & !y w d\btless be includ$ soon among ! regul> privileges ( ! tax-pay]s4 ,politicians address _! con/itu5ts4 ,prea*]s rea* ! /ay-at-homes4 ,great s+]s ?rill ?\s&s in/ead ( hundr$s4 ,soon x w be possible to he> ! f9e/ musical programs1 ent]ta9]s1 & orators1 )\t budg+ f "o's easy *air4 ,9 ! ,_w ,w> wireless prov$ ( ine/imable value4 ,airplanes1 in/ead ( fly+ aimlessly1 kept 9 con/ant t\* ) headqu>t]s4 ,bodies ( troops mov$ al]tly & intellig5tly4 ,%ips at sea talk$ freely1 ov] hundr$s ( miles4 ,sc\ts report$4 ,ev]y:]e its invisible aid 0 invok$4 ,9 "t ( peace1 h[ev]1 x has prov$ & w prove ! greate/ s]vant ( mank9d4 ,wireless messages n[ g daily f cont95t to cont95t1 & soon w g ar\nd ! _w ) ! same facility4 ,%ips 9 di/ress at sea c summon aid4 ,vessels ev]y:]e get ! day's news1 ev5 to baseball scores4 ,daily new tasks are be+ assign$ ?is tireless1 wireless mess5g]4 ,messages h be5 s5t & receiv$ by mov+ tra9s1 ! ,lackawanna & ! ,rock ,isl& railroads be+ pione]s 9 ?is field4 ,messages h also be5 receiv$ by automobiles1 & "o inv5tor has successfully demon/rat$ a motor c> controll$ entirely by wireless4 ,?is me?od ( communication is be+ employ$ m & m by newspap]s4 ,x is also ( great s]vice 9 report+ =e/ fires4 ,colleges are beg9n+ to take up ! subject1 "s ( ! fir/ be+ ,tufts ,college1 ,hunt] ,college1 ,pr9ceton1 ,yale1 ,h>v>d1 & ,columbia1 :i* h regul>ly organiz$ dep>tm5ts = /ud5ts 9 wireless4 ,in/ead ( ! unwieldy & =midable look+ app>atus ( a %ort "t ago1 exp]im5t]s are n[ vy+ ) ea* o!r 9 mak+ small or novel equipm5t4 ,portable sets ( all sorts are be+ fa%ion$1 f "o :i* w g into an ord9>y suitcase1 to "o s small x w easily slip into a ,br[nie cam]a4 ,"o receiv] depict$ 9 a newspap] 0 "o in* squ>e6 ,ano!r 0 a r+ = ! f+]1 ) a sett+ "o in* by five-eigh?s ( an in*1 & an umbrella z a gr\nd4 ,walk+ sets ) receiv]s fa/5$ to "o's belt are also common4 ,daily new novelties & m>vels are ann\nc$4 ,mean:ile1 ! radio amateur to :om ?is book is address$ may h 8 %>e 9 ! joys ( wireless4 ,to get all ( ^! good ?+s out ( ! e!r "o does n ne$ a rod or a gun--only a copp] wire made fa/ at ei!r end & a receiv+ set ( "s k9d4 ,if y are a %e] beg9n]1 !n y mu/ be v c>eful 9 buy+ y\r app>atus1 = s9ce ! great wave ( popul>ity has wa%$ wireless into ! he>ts ( ! p1 num]\s companies h sprung up & "s ( ^! are sell+ ! v]ie/ k9ds ( junk4 ,& h[1 y may ask1 are y go+ to be able to "k ! good f ! indiff]5t & bad sets8 ,by buy+ a make ( a firm ) an e/abli%$ reputation4 ,i h giv5 a few (fh& at ! end ( ?is book4 ,obvi\sly !re are _m o!rs ( m]it--s _m1 inde$1 t x w\ld be q impossible to get !m all 9 su* a li/1 b ^! w s]ve z a guide until y c *oose intellig5tly = y\rself4 ,a4 ,f4 ,c4 ,,cont5ts ,,*apt] ,i4 ,,h[ ,,to ,,beg9 ,,wireless ,k9ds ( ,wireless ,sy/ems--,p>ts ( a ,wireless ,sy/em--,! ,easie/ ,way to ,/>t--,ab\t ,a]ial ,wire ,sy/ems--,ab\t ! ,receiv+ ,app>atus--,ab\t ,transmitt+ ,/ations--,k9ds ( ,transmitt]s--,! ,sp>k ,gap ,wireless ,telegraph ,transmitt]--,! ,vacuum ,table ,telegraph ,transmitt]--,! ,wireless ,telephone ,transmitt]4 ,,ii4 ,,putt+ ,,up ,,y\r ,,a]ial ,k9ds ( ,a]ial ,wire ,sy/ems--,h[ to ,put ,up a ,*eap ,receiv+ ,a]ial--,a ,two-wire ,a]ial--,connect+ 9 ! ,gr\nd--,h[ to ,put up a ,good ,a]ial--,an ,inexp5sive ,good ,a]ial--,! ,be/ ,a]ial ,t ,c be ,made--,assembl+ ! ,a]ial--,mak+ a ,good ,gr\nd4 ,,iii4 ,,simple ,,telegraph ,,& ,,telephone ,,receiv+ ,,sets ,assembl$ ,wireless ,receiv+ ,sets--,assembl+ ,y\r ,own ,receiv+ ,set--,! ,cry/al ,detector--,! ,tun+ ,coil--,! ,loose ,c\pl$ ,tun+ ,coil--,fix$ & ,v>iable ,cond5s]s--,ab\t ,telephone ,receiv]s-- ,connect+ ,up ! ,p>ts--,receiv+ ,set ,no4 #b--;,adju/+ ! ,no4 #a ,set--,! ,tun+ ,coil--,adju/+ ! ,no4 #b ,set4 ,,iv4 ,,simple ,,telegraph ,,s5d+ ,,sets ,a ,*eap ,transmitt+ ,set 7,no4 #a7--,! ,sp>k ,coil--,! ,batt]y--,! ,telegraph ,key--,! ,sp>k ,gap--,! ,tun+ ,coil--,! ,high-t5sion ,cond5s]--,a ,bett] ,transmitt+ ,set 7,no4 #b7--,! ,alt]nat+ ,curr5t ,trans=m]--,! ,wireless ,key--,! ,sp>k ,gap--,! ,high-t5sion ,cond5s]--,! ,oscillation ,trans=m]--,connect+ ,up ! ,app>atus--,= ,direct ,curr5t--,h[ to ,adju/ ,y\r ,transmitt]4 ,tun+ ,) a ,hot ,wire ,ammet]--,to ,s5d ,out a #bjj-met] ,wave ,l5g?--,! ,use ( ! ,a]ial ,swit*--,a]ial ,swit* = a ,complete ,s5d+ & ,receiv+ ,set--,connect+ 9 ! ,lightn+ ,swit*4 ,v4 ,,electricity ,,simply ,,expla9$ ,electricity at ,re/ & 9 ,motion--,! ,electric ,curr5t & its ,circuit--,curr5t & ! ,amp]e--,resi/ance & ! ,ohm--,:at ,ohm's ,law ,is--,:at ! ,watt & ,kil[att ,are--,electromagnetic ,induction--,mutual ,induction--,high-frequ5cy ,curr5ts--,con/ants ( an ,oscillation ,circuit--,:at ,capacitance ,is--,:at ,inductance ,is--,:at ,resi/ance ,is--,! ,effect ( ,capacitance4 ,,vi4 ,,h[ ,,! ,,transmitt+ ,,& ,,receiv+ ,,sets ,,"w ,h[ ,transmitt+ ,set ,no4 #a ,works--,! ,batt]y & ,sp>k ,coil ,circuit--,*ang+ ! ,prim>y ,sp>k ,coil ,curr5t ,into ,second>y ,curr5ts--,:at ,ratio ( ,trans=mation ,means--,! ,second>y ,sp>k ,coil ,circuit--,! ,clos$ ,oscillation ,circuit--,h[ ,transmitt+ ,set ,no4 #b ,works--,) ,alt]nat+ ,curr5t--,) ,direct ,curr5t--,! ,rot>y ,sp>k ,gap--,! ,qu5*$ ,sp>k ,gap--,! ,oscillation ,trans=m]--,h[ ,receiv+ ,set ,no4 #a ,works--,h[ ,receiv+ ,set ,no4 #b ,works4 ,,vii4 ,,me*anical ,,& ,,electrical ,,tun+ ,damp$ & ,su/a9$ ,me*anical ,vibrations--,damp$ & ,su/a9$ ,oscillations--,ab\t ,me*anical ,tun+--,ab\t ,electric ,tun+4 ,,viii4 ,a ,,simple ,,vacuum ,,tube ,,detector ,,receiv+ ,,set ,assembl$ ,vacuum ,tube ,receiv+ ,set--,a ,simple ,vacuum ,tube ,receiv+ ,set--,! ,vacuum ,tube ,detector--,?ree ,electrode ,vacuum ,tube ,detector--,! ,dry ,cell & ,/orage ,batt]ies--,! ,filam5t ,rheo/at--,assembl+ ! ,p>ts--,connect+ ,up ! ,p>ts--,adju/+ ! ,vacuum ,tube ,detector ,receiv+ ,set4 ,,ix4 ,,vacuum ,,tube ,,amplifi] ,,receiv+ ,,sets ,a ,grid ,leak ,amplifi] ,receiv+ ,set4 ,) ,cry/al ,detector--,! ,fix$ ,resi/ance ,unit1 or ,grid ,leak--,assembl+ ! ,p>ts = a ,cry/al ,detector ,set--,connect+ up ! ,p>ts = a ,cry/al ,detector--,a ,grid ,leak ,amplify+ ,receiv+ ,set ,) ,vacuum ,tube ,detector--,a ,radio ,frequ5cy ,trans=m] ,amplify+ ,receiv+ ,set--,an ,audio ,frequ5cy ,trans=m] ,amplify+ ,receiv+ ,set--,a ,six ,/ep ,amplifi] ,receiv+ ,set ) a ,loop ,a]ial--,h[ to ,prev5t ,h[l+4 ,x4 ,,reg5]ative ,,amplification ,,receiv+ ,,sets ,! ,simple/ ,type ( ,reg5]ative ,receiv+ ,set--,) ,loose ,c\pl$ ,tun+ ,coil--,connect+ ,up ! ,p>ts--,an ,effici5t ,reg5]ative ,receiv+ ,set4 ,) ,?ree ,coil ,loose ,c\pl]--,! ,a ,batt]y ,pot5tiomet]--,! ,p>ts & ,h[ to ,connect ,!m ,up--,a ,reg5]ative ,audio ,frequ5cy ,amplifi]--,! ,p>ts & ,h[ to ,connect ,!m ,up4 ,,xi4 ,,%ort ,,wave ,,reg5]ative ,,receiv+ ,,sets ,a ,%ort ,wave ,reg5]ative ,receiv]1 ) ,"o ,v>iomet] & ,?ree ,v>iable ,cond5s]s--,! ,v>ioc\pl]--,! ,v>iomet]--,connect+ ,up ! ,p>ts--,%ort ,wave ,reg5]ative ,receiv] ) ,two ,v>iomet]s & ,two ,v>iable ,cond5s]s--,! ,p>ts & ,h[ to ,connect ,!m ,up4 ,,xii4 ,,int]m$iate ,,& ,,long ,,wave ,,reg5]ative ,,receiv+ ,,sets ,int]m$iate ,wave ,receiv+ ,sets--,int]m$iate ,wave ,set ,) ,load+ ,coils--,! ,p>ts & ,h[ to ,connect ,!m ,up--,an ,int]m$iate ,wave ,set ) ,v>ioc\pl] ,inductance ,coils--,! ,p>ts & ,h[ to ,connect ,!m ,up--,a ,long ,wave ,receiv+ ,set--,! ,p>ts & ,h[ to ,connect ,!m ,up4 ,,xiii4 ,,het]odyne ,,or ,,beat ,,long ,,wave ,,telegraph ,,receiv+ ,,set ,:at ! ,het]odyne or ,beat ,me?od ,is--,! ,autodyne or ,self-het]odyne ,long ,wave ,receiv+ ,set--,! ,p>ts & ,connections ( an ,autodyne or ,self-het]odyne1 ,receiv+ ,set--,! ,sep>ate ,het]odyne ,long ,wave ,receiv+ ,set--,! ,p>ts & ,connections ( a ,sep>ate ,het]odyne ,long ,wave ,receiv+ ,set4 ,,xiv4 ,,headphones ,,& ,,l\d ,,speak]s ,wireless ,headphones--,h[ a ,bell ,telephone ,receiv] is ,made--,h[ a ,wireless ,headphone is ,made--,ab\t ,resi/ance1 ,turns ( ,wire & ,s5sitivity ( ,headphones--,! ,imp$ance ( ,headphones--,h[ ! ,headphones ,"w--,ab\t ,l\d ,speak]s--,! ,simple/ ,type ( ,l\d ,speak]--,ano!r ,simple ,k9d ( ,l\d ,speak]--,a ,?ird ,k9d ( ,simple ,l\d ,speak]--,a ,sup] ,l\d ,speak]4 ,,xv4 ,,op]ation ,,( ,,vacuum ,,tube ,,receptors ,:at is ,meant by ,ionization--,h[ ,electrons are ,sep>at$ f ,atoms--,action ( ! ,two ,electrode ,vacuum ,tube--,h[ ! ,two ,electrode ,tube ,acts z a ,detector--,h[ ! ,?ree ,electrode ,tube ,acts z a ,detector--,h[ ! ,vacuum ,tube ,acts z an ,amplifi]--,! ,op]ation ( a ,simple ,vacuum ,tube ,receiv+ ,set--,op]ation ( a ,reg5]ative ,vacuum ,tube ,receiv+ ,set--,op]ation ( ,autodyne & ,het]odyne ,receiv+ ,sets--,! ,autodyne1 or ,self-,het]odyne ,receiv+ ,set--,! ,sep>ate ,het]odyne ,receiv+ ,set4 ,,xvi4 ,,cont9u\s ,,wave ,,telegraph ,,transmitt+ ,,sets ,,) ,,direct ,,curr5t ,s\rces ( ,curr5t = ,telegraph ,transmitt+ ,sets--,an ,exp]im5tal ,cont9u\s ,wave ,telegraph ,transmitt]--,! ,app>atus ,y ,ne$--,! ,tun+ ,coil--,! ,cond5s]s--,! ,a]ial ,ammet]--,! ,buzz] & ,dry ,cell--,! ,telegraph ,key--,! ,vacuum ,tube ,oscillator--,! ,/orage ,batt]y--,! ,batt]y ,rheo/at--,! ,oscillation ,*oke ,coil--,transmitt] ,connectors--,! ,panel ,cut\t--,connect+ ,up ! ,transmitt+ ,app>atus--,a #ajj-mile ,c4 ,w4 ,telegraph ,transmitt]--,! ,app>atus ,y ,ne$--,! ,tun+ ,coil--,! ,a]ial ,cond5s]--,! ,a]ial ,ammet]--,! ,grid & ,block+ ,cond5s]s--,! ,key ,circuit ,app>atus--,! #e ,watt ,oscillator ,vacuum ,tube--,! ,/orage ,batt]y & ,rheo/at--,! ,filam5t ,voltmet]--,! ,oscillation ,*oke ,coil--,! ,motor-g5]ator ,set--,! ,panel ,cut-out--,! ,protective ,cond5s]--,connect+ ,up ! ,transmitt+ ,app>atus--,a #bjj-mile ,c4 ,w4 ,telegraph ,transmitt]--,a #ejj-mile ,c4 ,w4 ,telegraph ,transmitt]--,! ,app>atus & ,connections-- ,! #ej-watt ,vacuum ,tube ,oscillator--,! ,a]ial ,ammet]--,! ,grid ,leak ,resi/ance--,! ,oscillation ,*oke ,coil--,! ,filam5t ,rheo/at--,! ,filam5t ,/orage ,batt]y--,! ,protective ,cond5s]--,! ,motor-g5]ator--,a #ajjj-mile ,c4 ,w4 ,telegraph ,transmitt]4 ,,xvii4 ,,cont9u\s ,,wave ,,telegraph ,,transmitt+ ,,sets ,,) ,,alt]nat+ ,,curr5t ,a #ajj-mile ,c4 ,w4 ,telegraph ,transmitt+ ,set--,! ,app>atus ,requir$--,! ,*oke ,coils--,! ,milli-ammet]--,! ,a4 ,c4 ,p[] ,trans=m]--,connect+ ,up ! ,app>atus--,a #bjj- to #ejj-mile ,c4 ,w4 ,telegraph ,transmitt+ ,set-,a #ejj- to #ajjj-mile ,c4 ,w4 ,telegraph ,transmitt+ ,set--,! ,app>atus ,requir$--,! ,alt]nat+ ,curr5t ,p[] ,trans=m]-,connect+ ,up ! ,app>atus4 ,,xviii4 ,,wireless ,,telephone ,,transmitt+ ,,sets ,,) ,,direct ,,& ,,alt]nat+ ,,curr5ts ,a ,%ort ,di/ance ,wireless ,telephone ,transmitt+ ,set--,) #aaj-volt ,direct ,light+ ,curr5t--,! ,app>atus ,y ,ne$--,! ,microphone ,transmitt]--,connect+ ,up ! ,app>atus--,a #be- to #ej-mile ,wireless ,telephone ,transmitt]--,) ,direct ,curr5t ,motor ,g5]ator--,! ,app>atus ,y ,ne$--,! ,telephone ,induction ,coil--,! ,microphone ,trans=m]--,! ,magnetic ,modulator--,h[ ! ,app>atus is ,connect$ ,up--,a #ej- to #ajj-mile ,wireless ,telephone ,transmitt]--,) ,direct ,curr5t ,motor ,g5]ator--,! ,oscillation ,*oke ,coil--,! ,plate & ,grid ,circuit ,reactance ,coils--,connect+ up ! ,app>atus--,a #ajj- to #bjj-mile ,wireless ,telephone ,transmitt]--,) ,direct ,curr5t ,motor ,g5]ator--,a #ej- to #ajj-mile ,wireless ,telephone ,transmitt+ ,set--,) #ajj-volt ,alt]nat+ ,curr5t--,! ,app>atus ,y ,ne$--,! ,vacuum ,tube ,rectifi]--,! ,filt] ,cond5s]s--,! ,filt] ,reactance ,coil-- ,connect+ ,up ! ,app>atus--,a #ajj- to #bjj-mile ,wireless ,telephone ,transmitt+ ,set--,) #aaj-volt ,alt]nat+ ,curr5t--,app>atus ,requir$4 ,,xix4 ,,! ,,op]ation ,,( ,,vacuum ,,tube ,,transmitt]s ,! ,op]ation ( ! ,vacuum ,tube ,oscillator--,! ,op]ation ( ,c4 ,w4 ,telegraph ,transmitt]s ) ,direct ,curr5t--,%ort ,di/ance ,c4 ,w4 ,transmitt]--,! ,op]ation ( ! ,key ,circuit--,! ,op]ation ( ,c4 ,w4 ,telegraph ,transmitt+ ) ,direct ,curr5t--,! ,op]ation ( ,c4 ,w4 ,telegraph ,transmitt]s ) ,alt]nat+ ,curr5t--,) a ,s+le ,oscillator ,tube--,heat+ ! ,filam5t ) ,alt]nat+ ,curr5t--,! ,op]ation ( ,c4 ,w4 ,telegraph ,transmitt]s ) ,alt]nat+ ,curr5t-- ,) ,two ,oscillator ,tubes--,! ,op]ation ( ,wireless ,telephone ,transmitt]s ) ,direct ,curr5t--,%ort ,di/ance ,transmitt]--,! ,microphone ,transmitt]--,! ,op]ation ( ,wireless ,telephone ,transmitt]s ) ,direct ,curr5t--,long ,di/ance ,transmitt]s--,! ,op]ation ( ,microphone ,modulators--,! ,induction ,coil--,! ,microphone ,trans=m]--,! ,magnetic ,modulator--,op]ation ( ! ,vacuum ,tube z a ,modulator--,! ,op]ation ( ,wireless ,telephone ,transmitt]s ) ,alt]nat+ ,curr5t--,! ,op]ation ( ,rectifi] ,vacuum ,tubes--,! ,op]ation ( ,reactors & ,cond5s]s4 ,,xx4 ,,h[ ,,to ,,make ,a ,,receiv+ ,,set ,,= #e4jj ,,or ,,less4 ,! ,cry/al ,detector--,! ,tun+ ,coil--,! ,headphone--,h[ to ,m\nt ! ,p>ts--,! ,cond5s]--,h[ to ,connect ,up ! ,receptor4 ,,app5dix ,useful ,in=mation--,gloss>y--,wireless ,don'ts4 ,,li/ ,,( ,,figures ,fig4 #a4--,simple ,receiv+ ,set ,fig4 #b4--,simple ,transmitt+ ,set 7,a7 ,fig4 #c4--;,flat ,top1 or ,horizontal ,a]ial 7,b7 ,fig4 #c4--;,incl9$ ,a]ial 7,a7 ,fig4 #d4--;,inv]t$ ,l ,a]ial 7,b7 ,fig4 #d--,t ,a]ial ,fig4 #e4--,mat]ial = a ,simple ,a]ial ,wire ,sy/em 7,a7 ,fig4 #f4--,s+le ,wire ,a]ial = ,receiv+ 7,b7 ,fig4 #f4--,receiv+ ,a]ial ) ,sp>k ,gap ,lightn+ ,arre/] 7,c7 ,fig4 #f4--;,a]ial ) ,lightn+ ,swit* ,fig4 #g4--,two-wire ,a]ial 7,a7 ,fig4 #h4--,"p ( a ,good ,a]ial 7,b7 ,fig4 #h4--,! ,spread]s 7,a7 ,fig4 #i4--,! ,middle ,spread] 7,b7 ,fig4 #i4--,"o ,end ( ,a]ial ,complete 7,c7 ,fig4 #i4--,! ,lead+ 9 ,spread] 7,a7 ,fig4 #aj4--;,cross ,section ( ,cry/al ,detector 7,b7 ,fig4 #aj4--,! ,cry/al ,detector ,complete 7,a7 ,fig4 #aa4--,s*ematic ,diagram ( a ,d\ble ,slide ,tun+ ,coil 7,b7 ,fig4 #aa4--;,d\ble ,slide ,tun+ ,coil ,complete 7,a7 ,fig4 #ab4--,s*ematic ,diagram ( a ,loose ,c\pl] 7,b7 ,fig4 #ab4--,loose ,c\pl] ,complete 7,a7 ,fig4 #ac4--;,h[ a ,fix$ ,receiv+ ,cond5s] is ,built up 7,b7 ,fig4 #ac4--,! ,fix$ ,cond5s] ,complete 7,c7 & 7,d7 ,fig4 #ac4--,v>iable ,rot>y ,cond5s] ,fig4 #ad4--,pair ( ,wireless ,headphones 7,a7 ,fig4 #ae4--,top ,view ( ,app>atus ,lay\t = ,receiv+ ,set ,no4 #a 7,b7 ,fig4 #ae4--,wir+ ,diagram = ,receiv+ ,set ,no4 #a 7,a7 ,fig4 #af4--,top ,view ( ,app>atus ,lay\t = ,receiv+ ,set ,no4 #b 7,b7 ,fig4 #af4--,wir+ ,diagram = ,receiv+ ,set ,no4 #b ,fig4 #ag4--;,adju/+ ! ,receiv+ ,set 7,a7 & 7,b7 ,fig4 #ah4--,types ( ,sp>k ,coils = ,set ,no4 #a 7,c7 ,fig4 #ah4--,wir+ ,diagram ( ,sp>k ,coil ,fig4 #ai4--,o!r ,p>ts = ,transmitt+ ,set ,no4 #a 7,a7 ,fig4 #bj4--,top ,view ( ,app>atus ,lay\t = ,s5d+ ,set ,no4 #a 7,b7 ,fig4 #bj4--,wir+ ( ,diagram = ,s5d+ ,set ,no4 #a ,fig4 #ba4--,p>ts = ,transmitt+ ,set ,no4 #b 7,a7 ,fig4 #bb4--,top ,view ( ,app>atus ,lay\t = ,s5d+ ,set ,no4 #b 7,b7 ,fig4 #bb4--,wir+ ,diagram = ,s5d+ ,set ,no4 #b ,fig4 #bc4--,us+ a #aaj-volt ,direct ,curr5t ) an ,alt]nat+ curr5t ,trans=m] ,fig4 #bd4--,pr9ciple ( ! ,hot ,wire ,ammet] ,fig4 #be4--,k9ds ( ,a]ial ,swit*es ,fig4 #bf4--,wir+ ,diagram = a ,complete ,s5d+ & ,receiv+ ,set ,no4 #a ,fig4 #bg4--,wir+ ,diagram = ,complete ,s5d+ & ,receiv+ ,set ,no4 #b ,fig4 #bh4--,wat] ,analogue = ,electric ,pressure ,fig4 #bi4--,wat] ,analogues = ,direct & ,alt]nat+ ,curr5ts ,fig4 #cj4--;,h[ ! ,ammet] & ,voltmet] are ,us$ ,fig4 #ca4--,wat] ,valve ,analogue ( ,electric ,resi/ance 7,a7 & 7,b7 ,fig4 #cb4--;,h[ an ,electric ,curr5t is ,*ang$ into ,magnetic ,l9es ( ,=ce & ,^! into an ,electric ,curr5t 7,c7 & 7,d7 ,fig4 #cb4--;,h[ an ,electric ,curr5t ,sets up a ,magnetic ,field ,fig4 #cc4--,! ,effect ( ,resi/ance on ! ,dis*>ge ( an ,electric ,curr5t ,fig4 #cd4--;,damp$ & ,su/a9$ ,me*anical ,vibrations ,fig4 #ce4--;,damp$ & ,su/a9$ ,electric ,oscillations ,fig4 #cf4--,s\nd ,wave & ,electric ,wave ,tun$ ,s5d]s & ,receptors ,fig4 #cg4--,two ,electrode ,vacuum ,tube ,detectors ,fig4 #ch4--,?ree ,electrode ,vacuum ,tube ,detector & ,batt]y ,connections ,fig4 #ci4--;,a & ,b ,batt]ies = ,vacuum ,tube ,detectors ,fig4 #dj4--,rheo/at = ! ,a or ,/orage-batt]y ,curr5t 7,a7 ,fig4 #da4--,top ,view ( ,app>atus ,lay\t = ,vacuum ,tube ,detector ,receiv+ ,set 7,b7 ,fig4 #da4--,wir+ ,diagram ( a ,simple ,vacuum ,tube ,receiv+ ,set ,fig4 #db4--;,grid ,leaks & ,h[ to ,connect !m ,up ,fig4 #dc4--;,cry/al ,detector ,receiv+ ,set ) ,vacuum ,tube ,amplifi] 7,resi/ance ,c\pl$7 7,a7 ,fig4 #dd4--,vacuum ,tube ,detector ,receiv+ ,set ) ,"o ,/ep ,amplifi] 7,resi/ance ,c\pl$7 7,b7 ,fig4 #dd4--,wir+ ,diagram = ,us+ ,"o ,a or ,/orage ,batt]y ) an ,amplifi] & a ,detector ,tube 7,a7 ,fig4 #de4--,wir+ ,diagram = ,radio ,frequ5cy ,trans=m] ,amplify+ ,receiv+ ,set 7,b7 ,fig4 #de4--,radio ,frequ5cy ,trans=m] 7,a7 ,fig4 #df4--;,audio ,frequ5cy ,trans=m] 7,b7 ,fig4 #df4--,wir+ ,diagram = ,audio ,frequ5cy ,trans=m] ,amplify+ ,receiv+ ,set4 7,) ,vacuum ,tube ,detector & ,two ,/ep ,amplifi] ,tubes7 7,a7 ,fig4 #dg4--,six ,/ep ,amplifi] ) ,loop ,a]ial 7,b7 ,fig4 #dg4--;,effici5t ,reg5]ative ,receiv+ ,set 7,) ,?ree ,coil ,loose ,c\pl] ,tun]7 ,fig4 #dh4--,simple ,reg5]ative ,receiv+ ,set 7,) ,loose ,c\pl] ,tun]7 7,a7 ,fig4 #di4--;,diagram ( ,?ree ,coil ,loose ,c\pl] 7,b7 ,fig4 #di4--,?ree ,coil ,loose ,c\pl] ,tun] ,fig4 #ej4--;,honeycomb ,inductance ,coil ,fig4 #ea4--,! ,use ( ! ,pot5tiomet] ,fig4 #eb4--,reg5]ative ,audio ,frequ5cy ,amplifi] ,receiv+ ,set ,fig4 #ec4--;,h[ ! ,v>io ,c\pl] is ,made & ,works ,fig4 #ed4--;,h[ ! ,v>iomet] is ,made & ,works ,fig4 #ee4--,%ort ,wave ,reg5]ative ,receiv+ ,set 7,"o ,v>iomet] & ,?ree ,v>iable ,cond5s]s7 ,fig4 #ef4--,%ort ,wave ,reg5]ative ,receiv+ ,set 7,two ,v>iomet] & ,two ,v>iable ,cond5s]s7 ,fig4 #eg4--,wir+ ,diagram ,%[+ ,fix$ ,load+ ,coils = ,int]m$iate ,wave ,set ,fig4 #eh4--,wir+ ,digram ( ,int]m$iate ,wave ,receptor ) ,"o ,v>io ,c\pl] & #ab ,section ,bank-w\nd ,inductance ,coil ,fig4 #ei4--,wir+ ,diagram ,%[+ ,long ,wave ,receptor ) ,v>io ,c\pl]s & #h ,bank-w\nd ,inductance ,coils ,fig4 #fj4--,wir+ ,diagram ( ,long ,wave ,autodyne1 or ,self-het]odyne ,receptor 7,comp>e ) ,fig4 #gg7 ,fig4 #fa4--,wir+ ,diagram ( ,long ,wave ,sep>ate ,het]odyne ,receiv+ ,set ,fig4 #fb4--;,cross ,section ( ,bell ,telephone ,receiv] ,fig4 #fc4--;,cross ,section ( ,wireless ,headphone ,fig4 #fd4--,! ,wireless ,headphone ,fig4 #fe4--;,arkay ,l\d ,speak] ,fig4 #ff4--;,amplitone ,l\d ,speak] ,fig4 #fg4--;,amplitron ,l\d ,speak] ,fig4 #fh4--,magnavox ,l\d ,speak] ,fig4 #fi4--,s*ematic ,diagram ( an ,atom ,fig4 #gj4--;,action ( ,two-electrode ,vacuum ,tube 7,a7 & 7,b7 ,fig4 #ga4--;,h[ a ,two-electrode ,tube ,acts z ,relay or a ,detector 7,c7 ,fig4 #ga--,only ! ,positive ,"p ( ,oscillations ,goes ?r\gh ! ,tube 7,a7 & 7,b7 ,fig4 #gb4--;,h[ ! ,positive & ,negative ,voltages ( ! ,oscillations ,act on ! ,electrons 7,c7 ,fig4 #gb4--;,h[ ! ,?ree-electrode ,tube ,acts z ,detector & ,amplifi] 7,d7 ,fig4 #gb4--;,h[ ! ,oscillations ,control ! ,fl[ ( ! ,batt]y ,curr5t ?r\gh ! ,tube ,fig4 #gc4--;,h[ ! ,het]odyne ,receptor ,works ,fig4 #gd4--,sep>ate ,het]odyne ,oscillator 7,a7 ,fig4 #ge4--;,app>atus = ,exp]im5tal ,c4 ,w4 ,telegraph ,transmitt]4 7,b7 ,fig4 #ge4--;,app>atus = ,exp]im5tal ,c4 ,w4 ,telegraph ,transmitt]4 ,fig4 #gf4--;,exp]im5tal ,c4 ,w4 ,telegraph ,transmitt] ,fig4 #gg--;,app>atus ( #ajj-mile ,c4 ,w4 ,telegraph ,transmitt] ,fig4 #gh4--e- to #ej-watt ,c4 ,w4 ,telegraph ,transmitt] 7) a ,s+le ,oscillation ,tube7 ,fig4 #gi4--bjj-mile ,c4 ,w4 ,telegraph ,transmitt] 7) ,two ,tubes 9 ,p>allel7 ,fig4 #hj4--ej-watt ,oscillator ,vacuum ,tube ,fig4 #ha4--;,alt]nat+ ,curr5t ,p[] ,trans=m] 7= ,c4 ,w4 ,telegraphy & ,wireless ,telephony7 ,fig4 #hb4--,wir+ ,diagram = #bjj- to #ejj-mile ,c4 ,w4 ,telegraph ,transmitt+ ,set4 7,) ,alt]nat+ ,curr5t47 ,fig4 #hc--,wir+ ,diagram = #ejj- to #ajjj-mile ,c4 ,w4 ,telegraph ,transmitt] ,fig4 #hd4--,/&>d ,microphone ,transmitt] ,fig4 #he4--,wir+ ,diagram ( ,%ort ,di/ance ,wireless ,telephone ,set4 7,microphone 9 ,a]ial ,wire47 ,fig4 #hf4--,telephone ,induction ,coil 7us$ ) ,microphone ,transmitt]74 ,fig4 #hg4--,microphone ,trans=m] ,us$ ) ,microphone ,transmitt] ,fig4 #hh4--,magnetic ,modulator ,us$ ) ,microphone ,transmitt] 7,a7 ,fig4 #hi4--,wir+ ,diagram ( #be--to #ej-mile ,wireless ,telephone4 7,microphone ,modulator ,%unt$ ,ar\nd ,grid-leak ,cond5s]7 7,b7 ,fig4 #hi4--,microphone ,modulator ,connect$ 9 ,a]ial ,wire ,fig4 #ij4--,wir+ ,diagram ( #ej- to #ajj-mile ,wireless ,telephone ,transmitt+ ,set ,fig4 #ia4--,plate & ,grid ,circuit ,reactor ,fig4 #ib4--;,filt] ,reactor = ,smoo?+ ,out ,rectifi$ ,curr5ts ,fig4 #ic4--ajj- to #bjj-mile ,wireless ,telephone ,transmitt] 7,a7 & 7,b7 ,fig4 #id4--,op]ation ( ,vacuum ,tube ,oscillators 7,c7 ,fig4 #id4--;,h[ a ,direct ,curr5t ,sets up ,oscillations ,fig4 #ie4--,positive ,voltage ,only ,sets up ,oscillations ,fig4 #if4--,rasco ,baby ,cry/al ,detector ,fig4 #ig4--;,h[ ! ,tun+ ,coil is ,made ,fig4 #ih4--,mesco loop-ohm ,head ,set ,fig4 #ii4--,s*ematic ,lay\t ( ! #e4jj ,receiv+ ,set ,fig4 #ajj4--,wir+ ,diagram = ! #e4jj ,receiv+ ,set ,,li/ ,,( ,,illu/rations ,a4 ,fr$]ick ,coll9s1 ,inv5tor ( ! ,wireless ,telephone1 #ahii4 ,aw>d$ ,gold ,m$al = same1 ,alaska ,yukon ,pacific ,exposition1 #aiji ,coll9s' ,wireless ,telephone ,exhibit$ at ! ,madison ,squ>e ,g>d51 ,octob]1 #aijh ,g5]al ,p]%+ ,li/5+-9 ,! ,_w's ,l>ge/ ,radio ,receiv+ ,/ation4 ,own$ by ! ,radio ,corporation ( ,am]ica at ,rocky ,po9t ne> ,port ,jeff]son1 ,l4 ,i4 ,fir/ ,wireless ,college 9 ! ,_w1 at ,tufts ,college1 ,mass ,alex&] ,graham ,bell1 ,inv5tor ( ! ,telephone1 n[ an ard5t ,radio ,en?usia/ ,_w's ,l>ge/ ,l\d ,speak] ev] made4 ,in/all$ 9 ,lytle ,p>k1 ,c9c9nati1 ,ohio1 to p]mit ,presid5t ,h>d+'s ,address at ,po9t ,pleasant1 ,ohio1 dur+ ! ,grant ,c5t5>y ,celebration to be he>d )9 a radius ( "o squ>e ,unit$ ,/ates ,naval ,high ,p[] ,/ation1 ,arl+ton1 ,va4 ,g5]al view ( ,p[] ,room4 ,at ! left c be se5 ! ,control ,swit*bo>ds1 & ov]head1 ! great #cj ,k4,w4 ,arc ,transmitt] ) ,accessories ,! ,trans=m] & ,tun] ( ! ,_w's ,l>ge/ ,radio ,/ation4 ,own$ by ! ,radio ,corporation ( ,am]ica at ,rocky ,po9t ne> ,port ,jeff]son1 ,l4 ,i4 ,broadca/+ ,gov]nm5t ,reports by ,wireless f ,wa%+ton4 ,?is %[s ,mr4 ,gale at "w ) 8 set 9 ! ,po/ ,(fice ,dep>tm5t ,wireless ,receptor1 ! size ( a ,safety ,mat* ,box4 ,a ,y\?ful ,g5ius 9 ! p]son ( ,k5ne? ,r4 ,h9man1 :o is only twelve ye>s old1 has made a ,wireless ,receiv+ ,set t fits neatly into a ,safety ,mat* ,box4 ,) ?is ,in/rum5t & a ,pair ( ,ord9>y ,receiv]s1 he is able to cat* n only ,code ,messages b ! regul> ,broadca/+ ,programs f ,/ations ,tw5ty & ,?irty ,miles ,di/ant ,wireless ,set made into a ,r+1 design$ by ,alfr$ ,g4 ,r9eh>t1 ( ,elizabe?1 ,new ,j]sey4 ,?is little ,receptor is a ,practical ,set2 x w receive ,messages1 ,conc]ts1 etc41 measures #a by #e_/h by #g_/h4 ,an ord9>y ,umbrella is us$ z an ,a]ial ,,*apt] ,i ,,h[ ,,to ,,beg9 ,,wireless ,9 writ+ ?is book x is tak5 = grant$ t y are3 fir/1 "o ( ! sev]al hundr$ ?\s& p]sons 9 ! ,unit$ ,/ates :o are int]e/$ 9 wireless telegraphy & telephony2 second1 t y w\ld l to in/all an app>atus 9 y\r home1 & ?ird1 t x is all new to y4 ,n[ if y live 9 a city or t[n l>ge en\gh to support an electrical supply /ore1 !re y w f9d ! necess>y app>atus on sale1 & someone :o c tell y :at y want to "k ab\t x & h[ x works4 ,if y live away f ! m>ts & hives ( indu/ry y c s5d to v>i\s mak]s ( wireless app>atus ,footnote3 ,a li/ ( mak]s ( wireless app>atus w be f\nd 9 ! ,app5dix4 = _! catalogues & price-li/s & ^! w give y mu* useful in=mation4 ,b 9 ei!r case x is ! bett] plan = y to "k be=e y />t 9 to buy an outfit exactly :at app>atus y ne$ to produce ! result y h 9 m9d1 & ?is y c ga9 9 easy /eps by read+ ?is book4 ,k9ds ( ,wireless ,sy/ems4--,!re are two di/9ct k9ds ( wireless sy/ems & ^! are3 ! wireless telegraph sy/em1 & ! wireless telephone sy/em4 ,! diff]5ce betwe5 ! wireless telegraph & ! wireless telephone is t ! =m] transmits messages by means ( a telegraph key1 & ! latt] transmits conv]sation & music by means ( a microphone transmitt]4 ,9 o!r words1 ! same diff]5ce exi/s betwe5 !m 9 ?is respect z betwe5 ! ,morse telegraph & ! ,bell telephone4 ,p>ts ( a ,wireless ,sy/em4--,e complete wireless /ation1 :e!r telegraph or telephone1 consi/s ( ?ree *ief sep>ate & di/9ct p>ts & ^! are3 7a7 ! a]ial wire sy/em1 or ant5na z x is (t5 call$1 7b7 ! transmitt]1 or s5d]1 & 7c7 ! receiv]1 or1 m prop]ly1 ! receptor4 ,! a]ial wire is precisely ! same = ei!r wireless telegraphy or wireless telephony4 ,! transmitt] ( a wireless telegraph set g5]ally uses a sp>k gap = sett+ up ! electric oscillations1 :ile usually = wireless telephony a vacuum tube is employ$ = ?is purpose4 ,! receptor = wireless telegraphy & telephony is ! same & may include ei!r a cry/al detector or a vacuum tube detector1 z w be expla9$ pres5tly4 ,! ,easie/ ,way to ,/>t4--,fir/ ( all y mu/ obta9 a gov]nm5t lic5se to op]ate a s5d+ set1 b y d n ne$ a lic5se to put up & use a receiv+ set1 ?\gh y are requir$ by law to keep secret any messages :i* y may ov]he>4 ,s9ce no lic5se is ne$$ = a receiv+ set ! easie/ way to break into ! wireless game is to put up an a]ial & hook up a receiv+ set to x2 y c !n li/5-9 & he> :at is go+ on 9 ! all-p]vad+ e!r ar\nd y1 & y w soon f9d en\gh to make ?+s highly ent]ta9+4 ,ne>ly all ! big wireless companies h great /ations fitt$ ) p[]ful telephone transmitt]s & at giv5 h\rs ( ! day & night !y s5d out songs by popul> s+]s1 dance music by jazz or*e/ras1 fa%ion talks by & = ! ladies1 agricultural reports1 gov]nm5t wea!r =eca/s & o!r int]e/+ features4 ,!n by simply %ift+ ! slide on y\r tun+ coil y c (t5 tune-9 someone :o is s5d+ ,morse1 t is1 messages 9 ! dot & da% code1 or1 p]haps a fri5d :o has a wireless telephone transmitt] & is talk+4 ,( c\rse1 if y want to talk back y mu/ h a wireless transmitt]1 ei!r telegraphic or telephonic1 & ?is is a mu* m exp5sive "p ( ! app>atus ?an ! receptor1 bo? 9 its initial co/ & 9 its op]ation4 ,a wireless telegraph transmitt] is less co/ly ?an a wireless telephone transmitt] & x is a v good s*eme = y to le>n to s5d & receive telegraphic messages4 ,at ! pres5t "t1 h[ev]1 !re are fifte5 amateur receiv+ /ations 9 ! ,unit$ ,/ates to e s5d+ /ation1 s y c see t ! majority ( wireless folks c>e m = li/5+ 9 to ! broadca/+ ( news & music ?an to s5d+ out messages on _! own acc\nt4 ,! easie/ way to beg9 wireless1 !n1 is to put up an a]ial & hook up a receiv+ set to x4 ,ab\t ,a]ial ,wire ,sy/ems4--,to ! beg9n] :o wants to in/all a wireless /ation ! a]ial wire sy/em usually looms up z ! bigge/ ob/acle ( all1 & especially is ?is true if 8 h\se is )\t a flag pole1 or o!r elevation f :i* ! a]ial wire c be conv5i5tly susp5d$4 ,if y live 9 ! conge/$ "p ( a big city :]e !re are no y>ds &1 p>ticul>ly1 if y live 9 a flat build+ or an ap>tm5t h\se1 y w h to /r+ y\r a]ial wire on ! ro(1 & to d ?is y %\ld get ! own]'s1 or ag5t's1 p]mission4 ,?is is usually an easy ?+ to d :]e y only int5d to receive messages1 = "o or two ?9 wires support$ at ei!r end ( ! build+ are all t are ne$$4 ,if = any reason y _c put y\r a]ial on ! ro( !n run a wire along ! build+ outside ( y\r ap>tm5t1 &1 f9ally1 if ?is is n feasible1 connect y\r receiv] to a wire /rung up 9 y\r room1 or ev5 to an iron or a brass b$1 & y c /ill get ! ne>-by /ations4 ,an important "p ( ! a]ial wire sy/em is ! gr\nd1 t is1 y\r receiv+ set mu/ n only be connect$ ) ! a]ial wire1 b ) a wire t leads to & makes good contact ) ! moi/ e>? ( ! gr\nd4 ,:]e a h\se or a build+ is pip$ = gas1 wat] or /eam1 x is easy to make a gr\nd connection1 = all y h to d is to fa/5 ! wire to "o ( ! pipes ) a clamp4 ,footnote3 ,pipes are (t5 insulat$ f ! gr\nd1 :i* makes !m useless = ?is purpose4 ,:]e ! h\se is isolat$ !n a lot ( wires or a %eet ( copp] or ( z9c mu/ be buri$ 9 ! gr\nd at a suffici5t dep? to insure _! be+ kept moi/4 ,ab\t ! ,receiv+ ,app>atus4--,y c ei!r buy ! p>ts ( ! receiv+ app>atus sep>ate & hook !m up y\rself1 or y c buy ! app>atus already assembl$ 9 a set :i* is1 9 ! beg9n+1 p]haps1 ! bett] way4 ,! simple/ receiv+ set consi/s ( 7#a7 a detector1 7#b7 a tun+ coil1 & 7#c7 a telephone receiv] & ^! ?ree pieces ( app>atus are1 ( c\rse1 connect$ toge!r & are also connect$ to ! a]ial & gr\nd z ! diagram 9 ,fig4 #a cle>ly %[s4 ,!re are two *ief k9ds ( detectors us$ at ! pres5t "t & ^! are3 7a7 ! cry/al detector1 & 7b7 ! vacuum tube detector4 ,! cry/al detector is ! *eape/ & simple/1 b x is n z s5sitive z ! vacuum tube detector & x requires frequ5t adju/m5t4 ,a cry/al detector c be us$ ) or )\t a batt]y :ile ! vacuum tube detector requires two small batt]ies4 ,illu/ration3 ,fig4 #a4--,simple ,receiv+ ,set4 ,a tun+ coil ( ! simple/ k9d consi/s ( a s+le lay] ( copp] wire w\nd on a cyl9d] ) an adju/able1 or slid+1 contact1 b = %>p tun+ y ne$ a loose c\pl$ tun+ coil4 ,:]e a s+le coil tun] is us$ a fix$ cond5s] %\ld be connect$ ar\nd ! telephone receiv]s4 ,:]e a loose c\pl$ tun] is employ$ y %\ld h a v>iable cond5s] connect$ across ! clos$ oscillation circuit & a fix$ cond5s] across ! telephone receiv]s4 ,:5 li/5+-9 to di/ant /ations ! en]gy ( ! receiv$ wireless waves is (t5 s v feeble t 9 ord] to he> di/9ctly an amplifi] mu/ be us$4 ,to amplify ! incom+ s\nds a vacuum tube made l a detector is us$ & sometimes z _m z half-a-doz5 ( ^! tubes are connect$ 9 ! receiv+ circuit1 or 9 cascade1 z x is call$1 :5 ! s\nds are amplifi$1 t is magnifi$1 _m hundr$s ( times4 ,! telephone receiv] ( a receiv+ set is equally z important z ! detector4 ,a s+le receiv] c be us$ b a pair ( receiv]s connect$ ) a head-b& gives f> bett] results4 ,!n aga9 ! high] ! resi/ance ( ! receiv]s ! m s5sitive !y (t5 are & ^? w\nd to z high a resi/ance z #c1bjj ohms are made = use ) ! be/ sets4 ,to make ! incom+ signals1 conv]sation or music1 audible to a room full ( p in/ead ( to j y\rself y mu/ use :at is call$ a l\d speak]4 ,9 its simple/ =m ?is consi/s ( a metal cone l a megaphone to :i* is fitt$ a telephone receiv]4 ,ab\t ,transmitt+ ,/ations--,gett+ ,y\r ,lic5se4--,if y are go+ to in/all a wireless s5d+ app>atus1 ei!r telegraphic or telephonic1 y w h to secure a gov]nm5t lic5se = :i* no fee or *>ge ( any k9d is made4 ,!re are ?ree classes ( lic5ses issu$ to amateurs :o want to op]ate transmitt+ /ations & ^! are3 7#a7 ! re/rict$ amateur lic5se1 7#b7 ! g5]al amateur lic5se1 & 7#c7 ! special amateur lic5se4 ,if y are go+ to set up a transmitt] )9 five nautical miles ( any naval wireless /ation !n y w h to get a re/rict$ amateur lic5se :i* limits ! curr5t y use to half a kil[att ,footnote3 ,a ,kil[att is #a1jjj watts4 ,!re are #gdf watts 9 a horsep[]4 & ! wave l5g? y s5d out to #bjj met]s4 ,%\ld y live outside ( ! five-mile range ( a navy /ation !n y c get a g5]al amateur lic5se & ?is p]mits y to use a curr5t ( #a kil[att1 b y are likewise limit$ to a wave l5g? ( #bjj met]s4 ,b if y c %[ t y are do+ "s special k9d ( wireless "w & n us+ y\r s5d+ /ation = ! m]e pleasure y are gett+ out ( x y may be able to get a special amateur lic5se :i* gives y ! "r to s5d out wave l5g?s up to #cge met]s4 ,:5 y are ready to apply = y\r lic5se write to ! ,radio ,inspector ( :i*ev] "o ( ! foll[+ di/ricts y live 93 ,fir/ ,di/rict44444444444444,bo/on1 ,mass4 ,second 44444444444444,new ,york ,city ,?ird 44444444444444,baltimore1 ,md4 ,f\r? 44444444444444,norfolk1 ,va4 ,fif? 44444444444444,new ,orleans1 ,la4 ,six? 4444444444444 ,san ,francisco1 ,cal4 ,sev5? 4444444444444 ,seattle1 ,wa%4 ,eigh? 4444444444444 ,detroit1 ,mi*4 ,n9? 44444444444444,*icago1 ,ill4 ,k9ds ( ,transmitt]s4--,!re are two g5]al types ( transmitt]s us$ = s5d+ out wireless messages & ^! are3 7#a7 wireless telegraph transmitt]s1 & 7#b7 wireless telephone transmitt]s4 ,telegraph transmitt]s may use ei!r3 7a7 a jump-sp>k1 7b7 an electric arc1 or 7c7 a vacuum tube app>atus = s5d+ out dot & da% messages1 :ile telephone transmitt]s may use ei!r1 7a7 an electric arc1 or 7b7 a vacuum tube = s5d+ out vocal & musical s\nds4 ,amateurs g5]ally use a jump-sp>k = s5d+ wireless telegraph messages & ! vacuum tube = s5d+ wireless telephone messages4 ,! ,sp>k ,gap ,wireless ,telegraph ,transmitt]4--,! simple/ k9d ( a wireless telegraph transmitt] consi/s (3 7#a7 a s\rce ( direct or alt]nat+ curr5t1 7#b7 a telegraph key1 7#c7 a sp>k-coil or a trans=m]1 7#d7 a sp>k gap1 7#e7 an adju/able cond5s] & 7#f7 an oscillation trans=m]4 ,:]e dry cells or a /orage batt]y mu/ be us$ to supply ! curr5t = en]giz+ ! transmitt] a sp>k-coil c be employ$ & ^! may be _h 9 v>i\s sizes f a little fell[ :i* gives #a_/d-;in* sp>k up to a l>g] "o :i* gives a #f-;in* sp>k4 ,:]e m en]gy is ne$$ x is bett] practice to use a trans=m] & ?is c be work$ on an alt]nat+ curr5t ( #aaj volts1 or if only a #aaj volt direct curr5t is available !n an electrolytic int]rupt] mu/ be us$ to make & break ! curr5t4 ,a simple transmitt+ set ) an induction coil is %[n 9 ,fig4 #b4 ,illu/ration3 ,fig #b4--,simple ,transmitt+ ,set4 ,a wireless key is made l an ord9>y telegraph key except t :]e l>ge curr5ts are to be us$ x is some:at heavi] & is provid$ ) l>ge silv] contact po9ts4 ,sp>k gaps = amateur "w are usually (3 7#a7 ! pla9 or /ation>y type1 7#b7 ! rotat+ type1 & 7#c7 ! qu5*$ gap type4 ,! pla9 sp>k-gap is m suitable = small sp>k-coil sets1 & x is n s apt to break d[n ! trans=m] & cond5s] ( ! l>g] sets z ! rot>y gap4 ,! rot>y gap on ! o!r h& t5ds to prev5t arc+ & s ! break is quick] & !re is less dragg+ ( ! sp>k4 ,! qu5*$ gap is m effici5t ?an ei!r ! pla9 or rot>y gap & moreov] x is noiseless4 ,cond5s]s = sp>k telegraph transmitt]s c be ord9>y ,leyd5 j>s or glass plates coat$ ) t9 or copp] foil & set into a frame1 or !y c be built up ( mica & %eet metal emb$d$ 9 an insulat+ composition4 ,! glass plate cond5s]s are ! *eape/ & w s]ve y\r purpose well1 especially if !y are imm]s$ 9 oil4 ,tun+ coils1 sometimes call$ transmitt+ inductances & oscillation trans=m]s1 are ( v>i\s types4 ,! simple/ k9d is a transmitt+ inductance :i* consi/s ( #be or #cj turns ( copp] wire w\nd on an insulat+ tube or frame4 ,an oscillation trans=m] is a loose c\pl$ tun+ coil & x consi/s ( a prim>y coil =m$ ( a numb] ( turns ( copp] wire w\nd on a fix$ insulat+ support1 & a second>y coil ( ab\t twice ! numb] ( turns ( copp] wire :i* is likewise fix$ 9 an insulat+ support1 b ! coils are relatively movable4 ,an oscillation trans=m] 7in/ead ( a tun+ coil71 is requir$ by gov]nm5t regulations unless inductively c\pl$4 ,! ,vacuum ,tube ,telegraph ,transmitt]4--,?is consi/s (3 7#a7 a s\rce ( direct or alt]nat+ curr5t1 7#b7 a telegraph key1 7#c7 a vacuum tube oscillator1 7#d7 a tun+ coil1 & 7#e7 a cond5s]4 ,?is k9d ( a transmitt] sets up su/a9$ oscillations in/ead ( p]iodic oscillations :i* are produc$ by a sp>k gap set4 ,! advantages ( ?is k9d ( a sy/em w be f\nd expla9$ 9 ,*apt] ,,xvi4 ,! ,wireless ,telephone ,transmitt]4--,because a jump-sp>k sets up p]iodic oscillations1 t is1 ! oscillations are discont9u\s1 x _c be us$ = wireless telephony4 ,an electric arc or a vacuum tube sets up su/a9$ oscillations1 t is1 oscillations :i* are cont9u\s4 ,z x is f> easi] to keep ! oscillations go+ ) a vacuum tube ?an x is ) an arc ! =m] means has all b supplant$ ! latt] = wireless telephone transmitt]s4 ,! app>atus requir$ & ! connections us$ = wireless telephone sets w be describ$ 9 lat] *apt]s4 ,useful ,in=mation4--,x w\ld be wise = ! read] to turn to ! ,app5dix1 beg9n+ ) page #cja ( ?is book1 & famili>ize himself ) ! in=mation !re set d[n 9 tabul> & graphic =m4 ,= example1 ! fir/ table gives abbreviations ( electrical t]ms :i* are 9 g5]al use 9 all works deal+ ) ! subject4 ,y w also f9d !re brief def9itions ( electric & magnetic units1 :i* x w\ld be well to commit to memory2 or1 at lea/1 to make s ?or\ghly y\r own t :5 any ( ^! t]ms is m5tion$1 y w "k in/antly :at is be+ talk$ ab\t4 ,,*apt] ,,ii ,,putt+ ,,up ,,y\r ,,a]ial ,z inf]r$ 9 ! fir/ *apt]1 an a]ial = receiv+ does n h to be ne>ly z well made or put up z "o = s5d+4 ,b ?is does n mean t y c slip%od ! con/ruction & in/allation ( x1 = h[ev] simple x is1 ! job mu/ be done "r & 9 ?is case x is z easy to d x "r z wrong4 ,to s5d wireless telegraph & telephone messages to ! greate/ di/ances & to receive !m z di/9ctly z possible f ! greate/ di/ances y mu/ use = y\r a]ial 7#a7 copp] or alum9um wire1 7#b7 two or m wires1 7#c7 h !m ! prop] l5g?1 7#d7 h !m z high 9 ! air z y c1 7#e7 h !m well ap>t f ea* o!r1 & 7#f7 h !m well insulat$ f _! supports4 ,if y live 9 a flat build+ or an ap>tm5t h\se y c /r+ y\r a]ial wires f "o edge ( ! ro( to ! o!r & support !m by wood5 /ays z high above x z may be conv5i5t4 ,%\ld y live 9 a deta*$ h\se 9 ! city y c usually get y\r next-door neighbor to let y fa/5 "o end ( ! a]ial to 8 h\se & ?is w give y a good /ret* & a fairly high a]ial4 ,9 ! c\ntry y c /ret* y\r wires betwe5 ! h\se & b>n or ! w9dmill4 ,f ?is y w see t no matt] :]e y live y c ne>ly always f9d ways & means ( putt+ up an a]ial t w s]ve y\r ne$s )\t go+ to ! exp5se ( erect+ a ma/4 ,k9ds ( ,a]ial ,wire ,sy/ems4--,an amateur wireless a]ial c be any:]e f #be feet to #ajj feet long & if y c get a /ret* ( ! latt] l5g? & a height ( f #cj to #ge feet y w h "o ) :i* y c receive a ?\s& miles or m & s5d out z mu* en]gy z ! gov]nm5t w all[ y to s5d4 ,! k9d ( an a]ial t gives ! be/ results is "o ^: wire1 or wires1 are horizontal1 t is1 p>allel ) ! e>? "u x z %[n at ,a 9 ,fig4 #c4 ,if only "o end c be fix$ to "s elevat$ support !n y c secure ! o!r end to a po/ 9 ! gr\nd1 b ! slope ( ! a]ial %\ld n be m ?an #cj or #ce degrees f ! horizontal at mo/ z %[n at ,b4 ,illu/ration3 7,a7 ,fig4 #c4--;,flat top1 or ,horizontal ,a]ial4 ,illu/ration3 7,b7 ,fig4 #c4--;,incl9$ ,a]ial4 ,! lead+-9 wire1 t is1 ! wire t leads f & jo9s ! a]ial wire ) y\r s5d+ & receiv+ set1 c be connect$ to ! a]ial any:]e x is mo/ conv5i5t to d s1 b ! be/ results are _h :5 x is connect$ to "o end z %[n at ,a 9 ,fig4 #d1 9 :i* case x is call$ an inv]t$ ,l a]ial1 or :5 x is connect$ to x at ! middle z %[n at ,b1 :5 x is call$ a ,t a]ial4 ,! lead+-9 wire mu/ be c>efully insulat$ f ! outside ( ! build+ & also :]e x passes ?r\gh x to ! inside4 ,?is is done by means ( an insulat+ tube kn[n z a lead+-9 insulator1 or bulkhead insulator z x is sometimes call$4 ,illu/ration3 7,a7 ,fig4 #d4--;,inv]t$ ,l ,a]ial4 ,illu/ration3 7,b7 ,fig4 #d4--,t ,a]ial4 ,z a protection aga9/ lightn+ burn+ out y\r in/rum5ts y c use ei!r3 7#a7 an air-gap lightn+ arre/]1 7#b7 a vacuum tube protector1 or 7#c7 a lightn+ swit*1 :i* is bett]4 ,:i*ev] ( ^! devices is us$ x is connect$ 9 betwe5 ! a]ial & an outside gr\nd wire s t a direct circuit to ! e>? w be provid$ at all times except :5 y are s5d+ or receiv+4 ,s y\r a]ial in/ead ( be+ a m5ace really acts dur+ an electrical /orm l a lightn+ rod & x is !re=e a real protection4 ,! air-gap & vacuum tube lightn+ arre/]s are little devices t c be us$ only :]e y are go+ to receive1 :ile ! lightn+ swit* mu/ be us$ :]e y are go+ to s5d2 inde$1 9 "s localities ! ,fire ,und]writ]s require a l>ge lightn+ swit* to be us$ = receiv+ sets z well z s5d+ sets4 ,h[ to ,put ,up a ,*eap ,receiv+ ,a]ial4--,! k9d ( an a]ial wire sy/em y put up w dep5d1 *iefly1 on two ?+s1 & ^! are3 7#a7 y\r pocketbook1 & 7#b7 ! place :]e y live4 ,a ,s+le ,wire ,a]ial4--,?is is ! simple/ & *eape/ k9d ( a receiv+ a]ial t c be put up4 ,! fir/ ?+ to d is to f9d out ! l5g? ( wire y ne$ by measur+ ! span betwe5 ! two po9ts ( support2 !n add a suffici5t l5g? = ! lead+-9 wire & en\gh m to connect y\r receiv+ set ) ! radiator or wat] pipe4 ,y c use any size ( copp] or alum9um wire t is n small] ?an ,no4 #af ,br[n & ,%>pe gauge4 ,:5 y buy ! wire get also ! foll[+ mat]ial3 7#a7 two porcela9 insulators z %[n at ,a 9 ,fig4 #e2 7#b7 ?ree or f\r porcela9 knob insulators1 see ,b2 7#c7 ei!r 7a7 an air gap lightn+ arre/]1 see ,c1 or 7b7 a lightn+ swit* see ,d2 7#d7 a lead+-9 porcela9 tube insulator1 see ,e1 & 7#e7 a gr\nd clamp1 see ,f4 ,illu/ration3 ,fig4 #e4--,mat]ial = a ,simple ,a]ial ,wire ,sy/em4 ,to make ! a]ial slip ea* end ( ! wire ?r\gh a hole 9 ea* insulator & twi/ x fa/2 next cut (f & slip two m pieces ( wire ?r\gh ! o!r holes 9 ! insulators & twi/ !m fa/ & !n secure ^! to ! supports at ! ends ( ! build+4 ,take ! piece y are go+ to use = ! lead+-9 wire1 twi/ x ar\nd ! a]ial wire & sold] x !re :5 x w look l ,a 9 ,fig4 #f4 ,n[ if y int5d to use ! air gap lightn+ arre/] fa/5 x to ! wall ( ! build+ outside ( y\r w9d[1 & br+ ! lead+-9 wire f ! a]ial to ! top b9d+ po/ ( y\r arre/] & keep x cle> ( ev]y?+ z %[n at ,b4 ,if y\r a]ial is on ! ro( & y h to br+ ! lead+-9 wire ov] ! cornice or ar\nd a corn] fix a porcela9 knob insulator to ! "o or ! o!r & fa/5 ! wire to x4 ,illu/ration3 7,a7 ,fig4 #f4--,s+le ,wire ,a]ial = ,receiv+4 ,illu/ration3 7,b7 ,fig4 #f4--,receiv+ ,a]ial ) ,air ,gap ,lightn+ ,arre/]4 ,illu/ration3 7,c7 ,fig4 #f4--;,a]ial ) ,lightn+ ,swit*4 ,next bore a hole ?r\gh ! frame ( ! w9d[ at a po9t ne>e/ y\r receiv+ set & pu% a porcela9 tube #e_/h in* 9 diamet] & #e or #f in*es long1 ?r\gh x4 ,connect a l5g? ( wire to ! top po/ ( ! arre/] or j above x to ! wire1 run ?is ?r\gh ! lead+-9 insulator & connect x to ! slid] ( y\r tun+ coil4 ,screw ! end ( a piece ( heavy copp] wire to ! l[] po/ ( ! arre/] & run x to ! gr\nd1 on porcela9 knobs if necess>y1 & sold] x to an iron rod or pipe :i* y h driv5 into ! e>?4 ,f9ally connect ! fix$ t]m9al ( y\r tun+ coil ) ! wat] pipe or radiator inside ( ! h\se by means ( ! gr\nd clamp z %[n 9 ! diagrammatic sket* at ,b 9 ,fig4 #f & y are ready to tune 94 ,if y want to use a lightn+ swit* in/ead ( ! air-gap arre/] !n fa/5 x to ! outside wall in/ead ( ! latt] & screw ! free end ( ! lead+-9 wire f ! a]ial to ! middle po/ ( x z %[n at ,c 9 ,fig4 #f4 ,run a wire f ! top po/ ?r\gh ! lead+-9 insulator & connect x ) ! slid] ( y\r tun+ coil4 ,next screw "o end ( a l5g? ( heavy copp] wire to ! l[] po/ ( ! a]ial swit* & run x to an iron pipe 9 ! gr\nd z describ$ above 9 connection ) ! sp>k-gap lightn+ arre/]2 !n connect ! fix$ t]m9al ( y\r tun+ coil ) ! radiator or wat] pipe & y\r a]ial wire sy/em w be complete z %[n at ,c 9 ,fig4 #f4 ,a ,two-wire ,a]ial4--,an a]ial ) two wires w give bett] results ?an a s+le wire & ?ree wires are bett] ?an two1 b y mu/ keep !m well ap>t4 ,to put up a two-wire a]ial get 7#a7 en\gh ,no4 #af1 or pref]ably ,no4 #ad1 solid or /r&$ copp] or alum9um wire1 7#b7 f\r porcela9 insulators1 see ,b 9 ,fig4 #e1 & 7#c7 two /icks ab\t #a in* ?ick1 #c in*es wide & #c or #d feet long1 = ! spread]s1 & bore #a_/h-;in* hole ?r\gh ea* end ( ea* "o4 ,n[ twi/ ! ends ( ! wires to ! insulators & !n cut (f f\r pieces ( wire ab\t #f feet long & run !m ?r\gh ! holes 9 ! wood spread]s4 ,f9ally twi/ ! ends ( ea* pair ( %ort wires to ! free ends ( ! insulators & !n twi/ ! free ends ( ! wires toge!r4 ,= ! lead+-9 wire t goes to ! lightn+ swit* take two l5g?s ( wire & twi/ "o end ( ea* "o ar\nd ! a]ial wires & sold] !m !re4 ,twi/ ! %ort wire ar\nd ! long wire & sold] ?is jo9t also :5 ! a]ial w look l ,fig4 #g4 ,br+ ! free end ( ! lead+-9 wire d[n to ! middle po/ ( ! lightn+ swit* & fa/5 x !re & connect up ! receiv] to x & ! gr\nd z describ$ "u ! caption ( ,a ,s+le ,wire ,a]ial4 ,illu/ration3 ,fig4 #g4--,two ,wire ,a]ial4 ,connect+ 9 ! ,gr\nd4--,if !re is a gas or wat] sy/em or a /eam-heat+ plant 9 y\r h\se y c make y\r gr\nd connection by clamp+ a gr\nd clamp to ! ne>e/ pipe z has be5 previ\sly describ$4 ,connect a l5g? ( b>e or insulat$ copp] wire ) x & br+ ?is up to ! table on :i* y h y\r receiv+ set4 ,if !re are no gr\nd$ pipes available !n y w h to make a good gr\nd :i* we %all describe pres5tly & lead ! gr\nd wire f y\r receiv+ set out ( ! w9d[ & d[n to x4 ,h[ to ,put ,up a ,good ,a]ial4--,:ile y c use ! *eap a]ial already describ$ = a small sp>k-coil s5d+ set y %\ld h a bett] insulat$ "o = a #a_/b or a #a kil[att trans=m] set4 ,! co/ = ! mat]ials = a good a]ial is small & :5 prop]ly made & well insulat$ x w give results t are all out ( proportion to ! co/ ( x4 ,an ,inexp5sive ,good ,a]ial4--,a f> bett] a]ial1 because x is m highly insulat$1 c be made by us+ midget insulators in/ead ( ! porcela9 insulators describ$ "u ! caption ( ,a ,s+le ,wire ,a]ial & us+ a small electrose lead+-9 insulator in/ead ( ! porcela9 bu%+4 ,?is makes a good s5d+ a]ial = small sets z well z a good receiv+ a]ial4 ,! ,be/ ,a]ial t ,c ,be ,made4--,to make ?is a]ial get ! foll[+ mat]ial toge!r3 7#a7 en\gh /r&$ or braid$ wire = ?ree or f\r l5g?s ( p>allel wires1 accord+ to ! numb] y want to use 7#b7 six or eight electrose ball insulators1 see ,b1 ,fig4 #h2 7#c7 two #e-;in* or #aj-;in* electrose /ra9 insulators1 see ,c2 7#d7 six or eight ,s-hooks1 see ,d2 "o l>ge )e ) "o eye = middle ( end spread]1 see ,e2 7#f7 two small] )es ) "o eye ea* = end spread]1 see ,e2 7#g7 two /ill small] )es1 ) two eyes ea* = ! ends ( ! end spread]s1 see ,e 7#h7 two ?imbles1 see ,f1 = #a_/d-;in* wire cable2 7#i7 six or eight h>d rubb] tubes or bu%+s z %[n at ,g2 & 7#aj7 two end spread]s1 see ,h2 "o middle spread]1 see ,i2 & "o lead+-9 spread]1 see ,j4 ,illu/ration3 7,a7 ,fig4 #h--,"p ( a ,good ,a]ial4 ,illu/ration3 7,b7 ,fig4 #h4--,! ,spread]s4 ,= ?is a]ial any "o ( a numb] ( k9ds ( wire c be us$ & among ^! are 7a7 /r&$ copp] wire2 7b7 braid$ copp] wire2 7c7 /r&$ silicon bronze wire1 & 7d7 /r&$ phosphor bronze wire4 ,/r&$ & braid$ copp] wire is v flexible z x is =m$ ( sev5 /r&s ( f9e wire twi/$ or braid$ toge!r & x is v good = %ort & light a]ials4 ,silicon bronze wire is /rong] ?an copp] wire & %\ld be us$ :]e a]ials are m ?an #ajj feet long1 :ile phosphor bronze wire is ! /ronge/ a]ial wire made & is us$ = high grade a]ials by ! comm]cial companies & ! ,gov]nm5t = _! high-p[] /ations4 ,! spread]s %\ld be made ( spruce1 & %\ld be #d feet #aj in*es long = a ?ree-wire a]ial & #g feet #a in* long = a f\r-wire a]ial z ! di/ance betwe5 ! wires %\ld be ab\t #bg in*es4 ,! end spread]s c be turn$ cyl9drically b x makes a bett] look+ job if !y tap] f ! middle to ! ends4 ,!y %\ld be #b-a_/d in*es 9 diamet] at ! middle & #a-c_/d in*es at ! ends4 ,! middle spread] c be cyl9drical & #b in*es 9 diamet]4 ,x mu/ h holes bor$ ?r\gh x at equidi/ant po9ts = ! h>d rubb] tubes2 ea* ( ^! %\ld be #e_/h in* 9 diamet] & h a hole #e_/cb in* 9 diamet] ?r\gh x = ! a]ial wire4 ,! lead+-9 spread] is also made ( spruce & is #a-a_/b in*es squ>e & #bf in*es long4 ,bore ?ree or f\r #e_/h-;in* holes at equidi/ant po9ts ?r\gh ?is spread] & ins]t h>d rubb] tubes 9 !m z ) ! middle spread]4 ,assembl+ ! ,a]ial4--,beg9 by measur+ (f ! l5g? ( ea* wire to be us$ & see to x t all ( !m are ( exactly ! same l5g?4 ,n[ pu% ! h>d rubb] insulators ?r\gh ! holes 9 ! middle spread] & ?read ! wires ?r\gh ! holes 9 ! insulators z %[n at ,a 9 ,fig #i4 ,next twi/ ! ends ( ea* wire to ! r+s ( ! ball insulators & !n put ! l>ge )es on ! middle ( ea* ( ! end spread]s2 fix ! o!r )es on ! spread]s s t !y w be #bg in*es ap>t & fa/5 ! ball insulators to ! eyes 9 ! )es ) ! ,s-hooks4 ,n[ slip a ?imble ?r\gh ! eye ( "o ( ! long /ra9 insulators1 ?read a l5g? ( /r&$ /eel wire #a_/d in* 9 diamet] ?r\gh x & fa/5 ! ends ( x to ! eyes 9 ! )es on ! ends ( ! spread]s4 ,illu/ration3 7,a7 ,fig4 #i4--,middle ,spread]4 ,illu/ration3 7,b7 ,fig4 #i4--,"o ,end ( ,a]ial ,complete4 ,illu/ration3 7,c7 ,fig4 #i4--,lead+ 9 ,spread]4 ,f9ally fa/5 a #dj-;in* l5g? ( /eel /r&$ wire to ea* ( ! eyes ( ! )es on ! middle ( ea* ( ! spread]s1 loop ! o!r end ov] ! ?imble & !n wrap ! end ar\nd ! wires t are fix$ to ! ends ( ! spread]s4 ,"o end ( ! a]ial is %[n complete at ,b 9 ,fig4 #i1 & f ?is y c see exactly h[ x is assembl$4 ,n[ cut (f ?ree or f\r pieces ( wire #ae or #bj feet long & twi/ & sold] ea* "o to "o ( ! a]ial wires2 !n slip !m ?r\gh ! h>d rubb] tubes 9 ! lead+-9 spread]1 br+ _! free ends toge!r z at ,c & twi/ & sold] !m to a l5g? ( wire long en\gh to rea* to y\r lightn+ swit* or in/rum5ts4 ,mak+ a ,good ,gr\nd4--,:]e y h to make a gr\nd y c d s ei!r by 7#a7 bury+ %eets ( z9c or copp] 9 ! moi/ e>?2 7#b7 bury+ a numb] ( wires 9 ! moi/ e>?1 or 7#c7 us+ a c\nt]poise4 ,to make a gr\nd ( ! fir/ k9d take half a doz5 l>ge %eets ( copp] or z9c1 cut !m into /rips a foot wide1 sold] !m all toge!r ) o!r /rips & bury !m deeply 9 ! gr\nd4 ,x is easi] to make a wire gr\nd1 say ( z _m or m wires z y h 9 y\r a]ial & connect !m toge!r ) cross wires4 ,to put su* a gr\nd 9 ! e>? y w h to use a pl[ to make ! furr[s deep en\gh to insure !m always be+ moi/4 ,9 ! c\nt]poise gr\nd y make up a sy/em ( wires exactly l y\r a]ial1 t is1 y insulate !m j z c>efully2 !n y support !m s t !y w be z close to ! gr\nd z possible & yet n t\* x or any?+ else4 ,?is & ! o!r two gr\nds j describ$ %\ld be plac$ directly "u ! a]ial wire if ! be/ results are to be _h4 ,9 us+ a c\nt]poise y mu/ br+ ! wire f x up to & ?r\gh ano!r lead+-9 insulator to y\r in/rum5ts4 ,,*apt] ,,iii ,,simple ,,telegraph ,,& ,,telephone ,,receiv+ ,,sets ,) a cry/al detector receiv+ set y c receive ei!r telegraphic dots & da%es or telephonic spee* & music4 ,y c buy a receiv+ set already assembl$ or y c buy ! diff]5t p>ts & assemble !m y\rself4 ,an assembl$ set is less bo!r 9 ! beg9n+ b if y l to exp]im5t y c hook up1 t is1 connect ! sep>ate p>ts toge!r y\rself & x is p]haps a little *eap] to d x ?is way4 ,!n aga91 by s do+ y get a lot ( valuable exp]i5ce 9 wireless "w & an und]/&+ ( ! work+s ( wireless t y _c get 9 any o!r way4 ,assembl$ ,wireless ,receiv+ ,sets4--,! *eape/ assembl$ receiv+ set ,footnote3 ,! ,m>vel1 made by ! ,radio ,mfg4 ,co41 ,new ,york ,city4 adv]tis$ is "o 9 :i* ! detector & tun+ coil is m\nt$ 9 a box4 ,x co/s #ae4jj1 & c be b\ght ( deal]s 9 electric supplies g5]ally4 ,?is price also includes a cry/al detector1 an adju/able tun+ coil1 a s+le telephone receiv] ) head-b& & ! wire1 porcela9 insulators1 lightn+ swit* & gr\nd clamp = ! a]ial wire sy/em4 ,x w receive wireless telegraph & telephone messages ov] a range ( f #aj to #be miles4 ,ano!r *eap unit receptor1 t is1 a complete wireless receiv+ set already m\nt$ :i* c be us$ ) a s+le a]ial is sold = #be4jj4 ,footnote3 ,! ,a]iola ,jr41 made by ! ,we/+h\se ,company1 ,pittsburgh1 ,pa4 ,?is set includes a cry/al detector1 a v>iable tun+ coil1 a fix$ cond5s] & a pair ( head telephone receiv]s4 ,x c also be us$ to receive ei!r telegraph or telephone messages f di/ances up to #be miles4 ,! a]ial equipm5t is n includ$ 9 ?is price1 b x c be b\ght = ab\t #b4ej extra4 ,assembl+ ,y\r ,own ,receiv+ ,set4--,9 ?is *apt] we %all g only into ! app>atus us$ = two simple receiv+ sets1 bo? ( :i* h a cry/al detector4 ,! fir/ set includes a d\ble-slide tun+ coil & ! second set employs a loose-c\pl$ tun+ coil1 or loose c\pl]1 z x is call$ = %ort4 ,= ei!r set y c use a pair ( #b1jjj- or #c1jjj-ohm head phones4 ,illu/ration3 orig9al ,und]wood & ,und]wood4 ,g5]al ,p]%+ ,li/5+ ,94 ,! ,cry/al ,detector4--,a cry/al detector consi/s (3 7#a7 ! frame1 7#b7 ! cry/al1 & 7#c7 ! wire po9t4 ,!re are any numb] ( diff]5t designs = frames1 ! idea be+ to provide a device t w 7a7 hold ! s5sitive cry/al firmly 9 place1 & yet p]mit ( its removal1 7b7 to p]mit ! wire po9t1 or electrode1 to be mov$ 9 any direction s t ! free po9t ( x c make contact ) ! mo/ s5sitive spot on ! cry/al & 7c7 to v>y ! pressure ( ! wire on ! cry/al4 ,a simple detector frame is %[n 9 ! cross-section at ,a 9 ,fig4 #aj2 ! cry/al1 :i* may be gal5a1 silicon or iron pyrites1 is held securely 9 a hold] :ile ! phosphor-bronze wire po9t :i* makes contact ) x1 is fix$ to "o end ( a ?read$ rod on ! o!r end ( :i* is a knob4 ,?is rod screws into & ?r\gh a sleeve fix$ to a ball t sets betwe5 two brass /&>ds & ?is p]mits an up & d[n or a side to side adju/m5t ( ! metal po9t :ile ! pressure ( x on ! cry/al is regulat$ by ! screw4 ,illu/ration3 7,a7 ,fig4 #aj4--;,cross ,section ( ,cry/al ,detector4 ,illu/ration3 7,b7 ,fig4 #aj4--,! ,cry/al ,detector ,complete4 ,a cry/al ( ?is k9d is (t5 enclos$ 9 a glass cyl9d] & ?is makes x reta9 its s5sitiv5ess = a mu* long] "t ?an if x 7 expos$ to du/ & moi/ure4 ,an upright type ( ?is detector c be b\ght = #b4be1 :ile a horizontal type1 z %[n at ,b1 c be b\ght = #b4ge4 ,gal5a is ! cry/al t is g5]ally us$1 =1 :ile x is n q z s5sitive z silicon & iron pyrites1 x is easi] to obta9 a s5sitive piece4 ,! ,tun+ ,coil4--,x is ) ! tun+ coil t y tune 9 & tune out diff]5t /ations & ?is y d by slid+ ! contacts to & fro ov] ! turns ( wire2 9 ?is way y v>y ! inductance & capacitance1 t is1 ! con/ants ( ! receiv+ circuits & s make !m receive electric waves1 t is1 wireless waves1 ( diff]5t l5g?s4 ,! ,d\ble ,slide ,tun+ ,coil4--,) ?is tun+ coil y c receive waves f any /ation up to #a1jjj met]s 9 l5g?4 ,"o ( ! ends ( ! coil ( wire connects ) ! b9d+ po/ m>k$ a 9 ,fig4 #aa1 & ! o!r end connects ) ! o!r b9d+ po/ m>k$ b1 :ile "o ( ! slid+ contacts is connect$ to ! b9d+ po/ c1 & ! o!r slid+ contact is connect$ ) ! b9d+ po/ d4 ,illu/ration3 7,a7 ,fig4 #aa4--,s*ematic ,diagram ( ,d\ble ,slide ,tun+ ,coil4 ,illu/ration3 7,b7 ,fig4 #aa4--;,d\ble ,slide ,tun+ ,coil ,complete4 ,:5 connect+ 9 ! tun+ coil1 only ! po/ a or ! po/ b is us$ z may be mo/ conv5i5t1 b ! o!r end ( ! wire :i* is connect$ to a po/ is left free2 j be> ?is po9t 9 m9d :5 y come to connect ! tun+ coil up ) ! o!r p>ts ( y\r receiv+ set4 ,! tun+ coil is %[n complete at ,b & x co/s #c4jj or #d4jj4 ,a triple slide tun+ coil con/ruct$ l ! d\ble slide tun] j describ$1 only ) m turns ( wire on x1 makes x possible to receive wave l5g?s up to #a1ejj met]s4 ,x co/s ab\t #f4jj4 ,! ,loose ,c\pl$ ,tun+ ,coil4--,) a loose c\pl]1 z ?is k9d ( a tun+ coil is call$ = %ort1 v selective tun+ is possible1 :i* means t y c tune 9 a /ation v %>ply1 & x w receive any wave l5g?s accord+ to size ( coils4 ,! prim>y coil is w\nd on a fix$ cyl9d] & its inductance is v>i$ by means ( a slid+ contact l ! d\ble slide tun+ coil describ$ above4 ,! second>y coil is w\nd on a cyl9d] t slides 9 & out ( ! prim>y coil4 ,! inductance ( ?is coil is v>i$ by means ( a swit* t makes contact ) ! fix$ po9ts1 ea* ( :i* is connect$ ) e tw5tie? turn ( wire z %[n 9 ! diagram ,a 9 ,fig4 #ab4 ,! loose c\pl]1 :i* is %[n complete at ,b1 co/s 9 ! neighborhood ( #h4jj or #aj4jj4 ,illu/ration3 7,a7 ,fig4 #ab4--,s*ematic ,diagram ( ,loose ,c\pl]4 ,illu/ration3 7,b7 ,fig4 #ab4--,loose ,c\pl] ,complete4 ,fix$ & ,v>iable ,cond5s]s4--,y d n require a cond5s] = a simple receiv+ set1 b if y w connect a fix$ cond5s] across y\r headphones y w get bett] results1 :ile a v>iable cond5s] connect$ 9 ! clos$ circuit ( a direct c\pl$ receiv+ set1 t is1 "o :]e a d\ble slide tun+ coil is us$1 makes x easy to tune v mu* m %>ply2 a v>iable cond5s] is absolutely necess>y :]e ! circuits are inductively c\pl$1 t is1 :]e a loose c\pl$ tun] is us$4 ,a fix$ cond5s] consi/s ( a numb] ( %eets ( pap] ) leaves ( t9-foil 9 betwe5 !m & s built up t "o end ( e o!r leaf ( t9-foil projects f ! opposite end ( ! pap] z %[n at ,a 9 ,fig4 #ac4 ,! pap] & t9-foil are !n press$ toge!r & impregnat$ ) an insulat+ comp\nd4 ,a fix$ cond5s] ( ! exact capacitance requir$ = connect+ across ! head phones is m\nt$ 9 a base fitt$ ) b9d+ po/s1 z %[n at ,b1 & co/s #ge c5ts4 7,pap] ones #be c5ts47 ,illu/ration3 7,a7 ,fig4 #ac4--;,h[ a ,fix$ ,receiv+ ,cond5s] is ,built up4 ,illu/ration3 7,b7 ,fig4 #ac4--,! ,fix$ ,cond5s] ,complete4 ,illu/ration3 7,c7 & 7,d7 ,fig4 #ac4--,! ,v>iable ,rot>y ,cond5s]4 ,a v>iable cond5s]1 see ,c1 ( ! rotat+ type is =m$ ( a set ( fix$ semi-circul> metal plates :i* are slightly sep>at$ f ea* o!r & betwe5 ^! a simil> set ( movable semi-circul> metal plates is made to int]leave2 ! latt] are secur$ to a %aft on ! top end ( :i* is a knob & by turn+ x ! capacitance ( ! cond5s]1 &1 h5ce1 ( ! circuit 9 :i* x is connect$1 is v>i$4 ,?is cond5s]1 :i* is %[n at ,d1 is made 9 two sizes1 ! small] "o be+ l>ge en\gh = all ord9>y wave l5g?s :ile ! l>g] "o is = proportionately long] wave l5g?s4 ,^! cond5s]s co/ #d4jj & #e4jj respectively4 ,ab\t ,telephone ,receiv]s4--,!re are a numb] ( makes ( head telephone receiv]s on ! m>ket t are design$ especially = wireless "w4 ,^! phones are w\nd to resi/ances ( f #ge ohms to #h1jjj ohms1 & co/ f #a4be = a receiv] )\t a cord or headb& to #ae4jj = a pair ( phones ) a cord & head b&4 ,y c get a receiv] w\nd to any resi/ance 9 betwe5 ! above values b = ei!r ( ! simple receiv+ sets su* z describ$ 9 ?is *apt] y ought to h a pair w\nd to at lea/ #b1jjj ohms & ^! w co/ y ab\t #e4jj4 ,a pair ( head phones ( ?is type is %[n 9 ,fig4 #ad4 ,illu/ration3 ,fig4 #ad4--,pair ( ,wireless ,head ,phones4 ,connect+ ,up ! ,p>ts--,receiv+ ,set ,no4 #a4--;,= ?is set get 7#a7 a cry/al detector1 7#b7 a two-slide tun+ coil1 7#c7 a fix$ cond5s]1 & 7#d7 a pair ( #b1jjj ohm head phones4 ,m\nt ! detector on ! "r-h& side ( a bo>d & ! tun+ coil on ! left-h& side4 ,screw 9 two b9d+ po/s = ! cord ends ( ! telephone receiv]s at a & b z %[n at ,a 9 ,fig4 #ae4 ,?is done connect "o ( ! end b9d+ po/s ( ! tun+ coil ) ! gr\nd wire & a po/ ( "o ( ! contact slides ) ! lightn+ arre/] or swit* :i* leads to ! a]ial wire4 ,illu/ration3 ,fig4 #ae4--,top ,view ( ,app>atus ,lay\t = ,receiv+ ,set ,no4 #a4 ,illu/ration3 7,b7 ,fig4 #ae4--,wir+ ,diagram = ,receiv+ ,set ,no4 #a4 ,n[ connect ! po/ ( ! o!r contact slide to "o ( ! po/s ( ! detector & ! o!r po/ ( ! latt] ) ! b9d+ po/ a1 !n connect ! b9d+ po/ b to ! gr\nd wire & sold] ! jo9t4 ,next connect ! ends ( ! telephone receiv] cord to ! po/s a & b & connect a fix$ cond5s] also ) ^! po/s1 all ( :i* are %[n 9 ! wir+ diagram at ,b1 & y are ready to adju/ ! set = receiv+4 ,receiv+ ,set ,no4 #b4--,use ! same k9d ( a detector & pair ( head phones z = ,set ,no4 #a1 b get 7#a7 a loose c\pl$ tun+ coil1 & 7#b7 a v>iable cond5s]4 ,m\nt ! loose c\pl] at ! back ( a bo>d on ! left-h& side & ! v>iable cond5s] on ! "r-h& side4 ,!n m\nt ! detector 9 front ( ! v>iable cond5s] & screw two b9d+ po/s1 a & b1 9 front ( ! tun+ coil z %[n at ,a 9 ,fig4 #af4 ,illu/ration3 ,fig4 #af4--,top view ( ,app>atus ,lay\t = ,receiv+ ,set ,no4 #b4 ,illu/ration3 7,b7 ,fig4 #af4--,wir+ ,diagram = ,receiv+ ,set ,no4 #b4 ,n[ connect ! po/ ( ! slid+ contact ( ! loose c\pl] ) ! wire t runs to ! lightn+ swit* & !nce to ! a]ial2 connect ! po/ ( ! prim>y coil1 :i* is ! outside coil1 ) ! gr\nd wire2 !n connect ! b9d+ po/ lead+ to ! swit* ( ! second>y coil1 :i* is ! inside coil1 ) "o ( ! po/s ( ! v>iable cond5s]1 & f9ally1 connect ! po/ t is jo9$ to "o end ( ! second>y coil ) ! o!r po/ ( ! v>iable cond5s]4 ,?is done1 connect "o ( ! po/s ( ! cond5s] ) "o ( ! po/s ( ! detector1 ! o!r po/ ( ! detector ) ! b9d+ po/ a1 & ! po/ b to ! o!r po/ ( ! v>iable cond5s]4 ,next connect a fix$ cond5s] to ! b9d+ po/s a & b & !n connect ! telephone receiv]s to ^! same po/s1 all ( :i* is %[n 9 ! wir+ diagram at ,b4 ,y are n[ ready to adju/ ! in/rum5ts4 ,9 mak+ ! connections use ,no4 #af or #ah insulat$ copp] wire & scrape ! ends clean :]e !y g into ! b9d+ po/s4 ,see1 also1 t all ( ! connections are tight & :]e y h to cross ! wires keep !m ap>t by an in* or s & always cross !m at "r angles4 ,adju/+ ! ,no4 #a ,set--,! ,detector4--,! fir/ ?+ to d is to te/ ! detector 9 ord] to f9d out if ! po9t ( ! contact wire is on a s5sitive spot ( ! cry/al4 ,to d ?is y ne$ a buzz]1 a swit* & a dry cell4 ,an electric bell f :i* ! gong has be5 remov$ w d = ! buzz]1 b y c get "o t is made specially = ! purpose1 = #ge c5ts1 :i* gives out a cle>1 high-pit*$ note t s\nds l a high-p[] /ation4 ,connect "o ( ! b9d+ po/s ( ! buzz] ) "o po/ ( ! swit*1 ! o!r po/ ( ! latt] ) ! z9c po/ ( ! dry cell & ! c>bon po/ ( ?is to ! o!r po/ ( ! buzz]4 ,!n connect ! po/ ( ! buzz] t is jo9$ to ! vibrator1 to ! gr\nd wire z %[n 9 ! wir+ diagram1 ,fig4 #ag4 ,n[ close ! swit* ( ! buzz] circuit1 put on y\r head phones1 & move ! wire po9t ( ! detector to v>i\s spots on ! cry/al until y he> ! sp>ks made by ! buzz] 9 y\r phones4 ,illu/ration3 ,fig4 #ag4--;,adju/+ ! ,receiv+ ,set4 ,!n v>y ! pressure ( ! po9t on ! cry/al until y he> ! sp>ks z l\d z possible4 ,aft] y h made ! adju/m5t op5 ! swit* & disconnect ! buzz] wire f ! gr\nd wire ( y\r set4 ,?is done1 be v c>eful n to j> ! detector or y w ?r[ x out ( adju/m5t & !n y w h to d x all ov] aga94 ,y are n[ ready to tune ! set ) ! tun+ coil & li/5 94 ,! ,tun+ ,coil4--,to tune ?is set move ! slide ,a ( ! d\ble-slide tun]1 see ,b 9 ,fig4 #ae1 ov] to ! end ( ! coil t is connect$ ) ! gr\nd wire & ! slide ,b ne> ! opposite end ( ! coil1 t is1 ! "o t has ! free end4 ,n[ move ! slide ,a t[>d ! ,b slide & :5 y he> ! dots & da%es1 or spee* or music1 t is com+ 9 z l\d z y c move ! ,b slide t[>d ! ,a slide until y he> /ill m l\dly4 ,a v few trials on y\r "p & y w be able to tune 9 or tune out any /ation y c he>1 if n too close or p[]ful4 ,illu/ration3 orig9al ,und]wood & ,und]wood4 ,! ,_w's ,l>ge/ ,radio ,receiv+ ,/ation4 ,own$ by ! ,radio ,corporation ( ,am]ica at ,rocky ,po9t ne> ,po9t ,jeff]son1 ,l4,i4 ,adju/+ ! ,no4 #b ,set4--,fir/ adju/ ! cry/al detector ) ! buzz] set z describ$ above ) ,set ,no4 #a1 !n turn ! knob ( y\r v>iable cond5s] s t ! movable plates are j half-way 91 pull ! second>y coil ( y\r loose-c\pl$ tun] half way out2 turn ! swit* lev] on x until x makes a contact ) ! middle contact po9t & set ! slid] ( ! prim>y coil half way betwe5 ! ends4 ,n[ li/5 9 = telegraphic signals or telephonic spee* or music2 :5 y he> "o or ! o!r slide ! second>y coil 9 & out ( ! prim>y coil until ! s\nds are l\de/2 n[ move ! contact swit* ov] ! po9ts =? & back until ! s\nds are /ill l\d]1 !n move ! slid] to & fro until ! s\nds are yet l\d] &1 f9ally1 turn ! knob ( ! cond5s] until ! s\nds are cle> & crisp4 ,:5 y h done all ( ^! ?+s y h1 9 ! p>lance ( ! wireless op]ator1 tun$ 9 & y are ready to receive :atev] is be+ s5t4 ,,*apt] ,,iv ,,simple ,,telegraph ,,s5d+ ,,sets ,a wireless telegraph transmitt+ set c be in/all$ = a v small am\nt ( money provid$ y are cont5t ) "o t has a limit$ range4 ,l>g] & bett] in/rum5ts c1 ( c\rse1 be _h = m money1 b h[ev] mu* y are will+ to sp5d /ill y are limit$ 9 y\r s5d+ radius by ! ,gov]nm5t's rules & regulations4 ,! be/ way1 & ! *eape/ 9 ! end1 to in/all a telegraph set is to buy ! sep>ate p>ts & hook !m up y\rself4 ,! usual type ( wireless telegraph transmitt] employs a disruptive dis*>ge1 or sp>k1 z x is call$1 = sett+ up ! oscillat+ curr5ts 9 ! a]ial wire sy/em & ?is is ! type ( app>atus describ$ 9 ?is *apt]4 ,!re are two ways to set up ! sp>ks & ^! are3 7#a7 ) an induction coil1 or sp>k-coil1 z x is commonly call$1 & 7#b7 ) an alt]nat+ curr5t trans=m]1 or p[] trans=m]1 z x is sometimes call$4 ,:]e y h to g5]ate ! curr5t ) a batt]y y mu/ use a sp>k coil1 b if y h a #aaj-volt direct or alt]nat+ light+ curr5t 9 y\r home y c use a trans=m] :i* w give y m p[]4 ,a ,*eap ,transmitt+ ,set 7,no4 #a74--;,= ?is set y w ne$3 7#a7 a sp>k-coil1 7#b7 a batt]y ( dry cells1 7#c7 a telegraph key1 7#d7 a sp>k gap1 7#e7 a high-t5sion cond5s]1 & 7#f7 an oscillation trans=m]4 ,!re are _m diff]5t makes & /yles ( ^! p>ts b 9 ! la/ analysis all ( !m are built on ! same und]ly+ bases & "w on ! same fundam5tal pr9ciples4 ,! ,sp>k-,coil4--,sp>k coils = wireless "w are made to give sp>ks f #a_/d in* 9 l5g? up to #f in*es 9 l5g?1 b z a sp>k coil t gives less ?an a #a-;in* sp>k has a v limit$ output x is be/ to get a coil t gives at lea/ a #a-;in* sp>k1 z ?is only co/s ab\t #h4jj1 & if y c get a #b- or a #d-;in* sp>k coil s mu* ! bett]4 ,!re are two g5]al /yles ( sp>k coils us$ = wireless & ^! are %[n at ,a & ,b 9 ,fig4 #ah4 ,illu/ration3 7,a7 & 7,b7 ,fig4 #ah4--,types ( ,sp>k ,coils = ,set4 ,no4 #a4 ,illu/ration3 7,c7 ,fig4 #ah4--,wir+ ,diagram ( ,sp>k ,coil ,a sp>k coil ( ei!r /yle consi/s ( 7a7 a s(t iron core on :i* is w\nd 7b7 a c\ple ( lay]s ( heavy insulat$ wire & ?is is call$ ! prim>y coil1 7c7 :ile ov] ?is1 b insulat$ f x1 is w\nd a l>ge numb] ( turns ( v f9e insulat$ copp] wire call$ ! second>y coil2 7d7 an int]rupt]1 or vibrator1 z x is commonly call$1 &1 f9ally1 7e7 a cond5s]4 ,! core1 prim>y & second>y coils =m a unit & ^! are set 9 a box or m\nt$ on top ( a holl[ wood5 base4 ,! cond5s] is plac$ 9 ! bottom ( ! box1 or on ! base1 :ile ! vibrator is m\nt$ on "o end ( ! box or on top ( ! base1 & x is ! only "p ( ! coil t ne$s adju/+4 ,! vibrator consi/s ( a /iff1 flat spr+ fix$ at "o end to ! box or base :ile x c>ries a piece ( s(t iron call$ an armature on its free end & ?is sets close to "o end ( ! s(t iron core4 ,insulat$ f ?is spr+ is a /&>d t c>ries an adju/+ screw on ! small end ( :i* is a plat9um po9t & ?is makes contact ) a small plat9um disk fix$ to ! spr+4 ,! cond5s] is =m$ ( alt]nate %eets ( pap] & t9foil built up 9 ! same fa%ion z ! receiv+ cond5s] describ$ "u ! caption ( ,fix$ & ,v>iable ,cond5s]s1 9 ,*apt] ,,iii4 ,! wir+ diagram ,c %[s h[ ! sp>k coil is wir$ up4 ,"o ( ! batt]y b9d+ po/s is connect$ ) "o end ( ! prim>y coil :ile ! o!r end ( ! latt] :i* is w\nd on ! s(t iron core connects ) ! spr+ ( ! vibrator4 ,! o!r batt]y b9d+ po/ connects ) ! /&>d t supports ! adju/+ screw4 ,! cond5s] is %unt$ across ! vibrator1 t is1 "o end ( ! cond5s] is connect$ ) ! spr+ & ! o!r end ( ! cond5s] is connect$ ) ! adju/+ screw /&>d4 ,! ends ( ! second>y coil lead to two b9d+ po/s1 :i* are usually plac$ on top ( ! sp>k coil & x is to ^! t ! sp>k gap is connect$4 ,! ,batt]y4--,?is c be =m$ ( dry cells or y c use a /orage batt]y to en]gize y\r coil4 ,= all coils t give less ?an a #a-;in* sp>k y %\ld use #e dry cells2 = #a-;& #b-;in* sp>k coils use #f or #h dry cells1 & = #c to #d-;in* sp>k coils use #h to #aj dry cells4 ,! way ! dry cells are connect$ toge!r to =m a batt]y w be %[n pres5tly4 ,a dry cell is %[n at ,a 9 ,fig1 #ai4 ,illu/ration3 ,fig4 #ai4--,o!r p>ts = ,transmitt+ ,set ,no4 #a ,! ,telegraph ,key4--,y c use an ord9>y ,morse telegraph key = ! s5d+ set & y c get "o ) a japann$ iron base = #a4ej 7or bett]1 "o made ( brass & :i* has #a_/h-;in* silv] contact po9ts = #c4jj4 ,a key ( ! latt] k9d is %[n at ,b74 ,! ,sp>k gap4--,x is 9 ! sp>k gap t ! high t5sion sp>k takes place4 ,! app>atus 9 :i* ! sp>k takes place is also call$ ! sp>k gap4 ,x consi/s ( a pair ( z9c plugs1 call$ electrodes1 fix$ to ! ends ( a pair ( ?read$ rods1 ) knobs on ! o!r ends1 & ^! screw into & ?r\gh a pair ( /&>ds z %[n at c4 ,?is is call$ a fix$1 or /ation>y sp>k gap & co/s ab\t #a4jj4 ,! ,tun+ ,coil4--,! transmitt+ inductance1 or s5d+ tun+ coil1 consi/s ( #bj to #cj turns ( ,no4 #h or #i h>d drawn copp] wire w\nd on a slott$ insulat$ =m & m\nt$ on a wood5 base4 ,x is provid$ ) clips s t y c cut 9 & cut out z _m turns ( wire z y wi% & s tune ! s5d+ circuits to s5d out :atev] wave l5g? y desire4 ,x is %[n at d1 & co/s ab\t #e4jj4 ,see also ,oscillation ,trans=m]1 page #fc ,*apt] ,,iv4 ,! ,high ,t5sion ,cond5s]4--,high t5sion cond5s]s1 t is1 cond5s]s :i* w /& up "u high pot5tials1 or electric pressures1 c be b\ght 9 units or sections4 ,^! cond5s]s are made up ( ?9 brass plates insulat$ ) a special comp\nd & press$ into a compact =m4 ,! capacitance ,footnote3 ,?is is ! capacity ( ! cond5s]4 ( "o section is en\gh = a transmitt+ set us+ a sp>k coil t gives a #b in* sp>k or less & two sections connect$ toge!r %\ld be us$ = coils giv+ f #b to #d in* sp>ks4 ,x is %[n at e4 ,connect+ ,up ! ,app>atus4--,y\r s5d+ set %\ld be m\nt$ on a table1 or a b5*1 :]e x ne$ n be mov$4 ,place ! key 9 ab\t ! middle ( ! table & d[n 9 front1 & ! sp>k coil to ! left & well to ! back b s t ! vibrator end w be to ! "r1 z ?is w enable y to adju/ x easily4 ,place ! batt]y back ( ! sp>k coil & ! tun+ coil 7oscillation trans=m]7 to ! "r ( ! sp>k coil & back ( ! key1 all ( :i* is %[n 9 ! lay\t at ,a 9 ,fig4 #bj4 ,illu/ration3 7,a7 ,fig4 #bj4--,top ,view ( ,app>atus ,lay\t = ,s5d+ ,set ,no4 #a4 ,illu/ration3 7,b7 ,fig4 #bj4--,wir+ ( ,diagram = ,s5d+ ,set ,no4 #a4 ,= ! l[ voltage circuit1 t is ! batt]y circuit1 use ,no4 #ab or #ad insulat$ copp] wire4 ,connect all ( ! dry cells toge!r 9 s]ies1 t is1 connect ! z9c ( "o cell ) ! c>bon ( ! next & s on until all ( !m are connect$ up4 ,!n connect ! c>bon ( ! end cell ) "o ( ! po/s ( ! key1 ! z9c ( ! o!r end cell ) "o ( ! prim>y po/s ( ! sp>k coil & ! o!r prim>y po/ ( ! sp>k coil ) ! o!r po/ ( ! key1 :5 ! prim>y circuit w be complete4 ,= ! high t5sion circuits1 t is1 ! oscillation circuits1 y may use ei!r b>e or insulat$ copp] wire b y mu/ be c>eful t !y d n t\* ! table1 ea* o!r1 or any "p ( ! app>atus1 except1 ( c\rse1 ! po/s !y are connect$ )4 ,connect "o ( ! po/s ( ! second>y coil ( ! sp>k coil ) "o ( ! po/s ( ! sp>k gap1 & ! o!r po/ ) "o ( ! po/s ( ! cond5s]2 !n connect ! o!r po/ ( ! cond5s] ) ! l[] spr+ clip ( ! tun+ coil & also connect ?is clip ) ! gr\nd4 ,?is done1 connect ! middle spr+ clip ) "o ( ! po/s ( ! sp>k gap1 &1 f9ally1 connect ! top clip ) ! a]ial wire & y\r transmitt+ set is ready to be tun$4 ,a wir+ diagram ( ! connections is %[n at ,b4 ,z ?is set is tun$ 9 ! same way z ,set ,no4 #b :i* foll[s1 y are ref]r$ to ! end ( ?is *apt]4 ,a ,bett] ,transmitt+ ,set 7,no4 #b74--,! app>atus = ?is set includes3 7#a7 an alt]nat+ curr5t trans=m]1 7#b7 a wireless telegraph key1 7#c7 a fix$1 a rot>y1 or a qu5*$ sp>k gap1 7#d7 a cond5s]1 & 7#e7 an oscillation trans=m]4 ,if y h a #aaj volt direct light+ curr5t 9 y\r home in/ead ( #aaj volt alt]nat+ curr5t1 !n y w also ne$ 7#f7 an electrolytic int]rupt]1 = 9 ?is case ! prim>y circuit ( ! trans=m] mu/ be made & brok5 rapidly 9 ord] to set up alt]nat+ curr5ts 9 ! second>y coil4 ,! ,alt]nat+ ,curr5t ,trans=m]4--,an alt]nat+ curr5t1 or p[]1 trans=m] is made on ! same pr9ciple z a sp>k coil1 t is1 x has a s(t iron core1 a prim>y coil =m$ ( a c\ple ( lay]s ( heavy wire1 & a second>y coil w\nd up ( a l>ge numb] ( turns ( v f9e wire4 ,unlike ! sp>k coil1 h[ev]1 :i* has an op5 magnetic core & ^: second>y coil is w\nd on ! prim>y coil1 ! trans=m] has a clos$ magnetic core1 ) ! prim>y coil w\nd on "o ( ! legs ( ! core & ! second>y w\nd on ! o!r leg4 ,x has nei!r a vibrator nor a cond5s]4 ,a pla9 trans=m] is %[n at ,a 9 ,fig4 #ba4 ,illu/ration3 ,fig4 #ba4--,p>ts = ,transmitt+ ,set ,no4 #b4 ,a trans=m] ( ?is k9d c be b\ght ei!r 7a7 unm\nt$1 t is1 j ! b>e trans=m]1 or 7b7 fully m\nt$1 t is1 fitt$ ) an iron /&1 m\nt$ on an insulat+ base on :i* are a pair ( prim>y b9d+ po/s1 :ile ! second>y is provid$ ) a safety sp>k gap4 ,!re are ?ree sizes ( trans=m]s ( ?is k9d made & !y are rat$ at #a_/d1 #a_/b & #a kil[att1 respectively1 !y deliv] a second>y curr5t ( #i1jjj1 #aa1jjj & #be1jjj volts1 accord+ to size1 & co/ #af4jj1 #bb4jj & #cc4jj :5 fully m\nt$2 a r$uction ( #c4jj1 #d4jj & #e4jj is made :5 !y are unm\nt$4 ,all ( ^! trans=m]s op]ate on #aaj volt1 #fj cycle curr5t & c be connect$ directly to ! s\rce ( alt]nat+ curr5t4 ,! ,wireless ,key4--,= ?is transmitt+ set a /&>d wireless key %\ld be us$ z %[n at ,b4 ,x is made ab\t ! same z a regul> telegraph key b x is mu* heavi]1 ! contact po9ts are l>g] & in/ead ( ! curr5t be+ l$ ?r\gh ! be>+s z 9 an ord9>y key1 x is c>ri$ by heavy conductors directly to ! contact po9ts4 ,?is key is made 9 ?ree sizes & ! fir/ w c>ry a curr5t ( #e amp]es,footnote3 ,see ,app5dix = def9ition4 & co/s #d4jj1 ! second w c>ry a curr5t ( #aj amp]es & co/s #f4ej1 :ile ! ?ird w c>ry a curr5t ( #bj amp]es & co/s #g4ej4 ,! ,sp>k ,gap4--,ei!r a fix$1 a rot>y1 or a qu5*$ sp>k gap c be us$ ) ?is set1 b ! =m] is seldom us$ except ) sp>k-coil sets1 z x is v h>d to keep ! sp>ks f arc+ :5 l>ge curr5ts are us$4 ,a rot>y sp>k gap comprises a :eel1 driv5 by a small electric motor1 ) project+ plugs1 or electrodes1 on x & a pair ( /ation>y plugs on ea* side ( ! :eel z %[n at ,c4 ,! numb] ( sp>ks p] second c be v>i$ by *ang+ ! spe$ ( ! :eel & :5 x is rotat$ rapidly x s5ds out signals ( a high pit* :i* are easy to read at ! receiv+ end4 ,a rot>y gap ) a #aaj-volt motor co/s ab\t #be4jj4 ,a qu5*$ sp>k gap n only elim9ates ! noise ( ! ord9>y gap b1 :5 prop]ly design$1 x increases ! range ( an induction coil set "s #bjj p] c5t4 ,a #a_/d kil[att qu5*$ gap co/s #aj4jj4 ,footnote3 ,see ,app5dix = def9ition4 ,! ,high ,t5sion ,cond5s]4--,s9ce1 if y are an amateur1 y c only s5d out waves t are #bjj met]s 9 l5g?1 y c only use a cond5s] t has a capacitance ( 4#jjg micr(>ad4 ,footnote3 ,see ,app5dix = def9ition4 ,a sectional high t5sion cond5s] l ! "o describ$ 9 connection ) ,set ,no4 #a c be us$ ) ?is set b x mu/ h a capacitance ( n m ?an 4#jjg micr(>ad4 ,a cond5s] ( ?is value = a #a_/d-kil[att trans=m] co/s #g4jj2 = a #a_/b-kil[att trans=m] #ad4jj1 & = a #a-kil[att trans=m] #ba4jj4 ,see ,e1 ,fig4 #ai4 ,! ,oscillation ,trans=m]4--,) an oscillation trans=m] y c tune mu* m %>ply ?an ) a s+le inductance coil tun]4 ,! prim>y coil is =m$ ( #f turns ( copp] /rip1 or ,no4 #i copp] wire1 & ! second>y is =m$ ( #i turns ( /rip1 or wire4 ,! prim>y coil1 :i* is ! outside coil1 is h+$ to ! base & c be rais$ or l[]$ l ! lid ( a box4 ,:5 x is l[]$ ! prim>y & second>y coils are 9 ! same plane & :5 x is rais$ ! coils set at an angle to ea* o!r4 ,x is %[n at ,d & co/s #e4jj4 ,connect+ ,up ! ,app>atus4 ,= ,alt]nat+ ,curr5t4--,screw ! key to ! table ab\t ! middle ( x & ne> ! front edge2 place ! high t5sion cond5s] back ( x & ! oscillation trans=m] back ( ! latt]2 set ! alt]nat+ curr5t trans=m] to ! left ( ! oscillation trans=m] & place ! rot>y or qu5*$ sp>k gap 9 front ( x4 ,n[ br+ a pair ( ,no4 #ab or #ad insulat$ wires f ! #aaj volt light+ leads & connect !m ) a s+le-?r[1 d\ble-pole swit*2 connect "o pole ( ! swit* ) "o ( ! po/s ( ! prim>y coil ( ! alt]nat+ p[] trans=m] & connect ! o!r po/ ( ! latt] ) "o ( ! po/s ( y\r key1 & ! o!r po/ ( ?is ) ! o!r pole ( ! swit*4 ,n[ connect ! motor ( ! rot>y sp>k gap to ! p[] circuit & put a s+le-pole1 s+le-?r[ swit* 9 ! motor circuit1 all ( :i* is %[n at ,a 9 ,fig4 #bb4 ,illu/ration3 7,a7 ,fig4 #bb4--,top ,view ( ,app>atus ,lay\t = ,s5d+ ,set ,no4 #b4 ,illu/ration3 7,b7 ,fig4 #bb4--,wir+ ,diagram = ,s5d+ ,set ,no4 #b4 ,next connect ! po/s ( ! second>y coil to ! po/s ( ! rot>y or qu5*$ sp>k gap & connect "o po/ ( ! latt] to "o po/ ( ! cond5s]1 ! o!r po/ ( ?is to ! po/ ( ! prim>y coil ( ! oscillation trans=m]1 :i* is ! inside coil1 & ! clip ( ! prim>y coil to ! o!r sp>k gap po/4 ,?is completes ! clos$ oscillation circuit4 ,f9ally connect ! po/ ( ! second>y coil ( ! oscillation trans=m] to ! gr\nd & ! clip ( x to ! wire lead+ to ! a]ial :5 y are ready to tune ! set4 ,a wir+ diagram ( ! connections is %[n at ,b4 ,= ,direct ,curr5t4--,:]e y h #aaj volt direct curr5t y mu/ connect 9 an electrolytic int]rupt]4 ,?is int]rupt]1 :i* is %[n at ,a & ,b 9 ,fig4 #bc1 consi/s ( 7#a7 a j> fill$ ) a solution ( #a "p ( sulphuric acid & #i p>ts ( wat]1 7#b7 a lead electrode hav+ a l>ge surface fa/5$ to ! cov] ( surface t sets 9 a porcela9 sleeve & ^: end re/s on ! bottom ( ! j>4 ,illu/ration3 ,fig4 #bc4--,us+ #aaj ,volt ,direct ,curr5t ) an ,alt]nat+ ,curr5t ,trans=m]4 ,:5 ^! electrodes are connect$ 9 s]ies ) ! prim>y ( a l>ge sp>k coil or an alt]nat+ curr5t trans=m]1 see ,c1 & a direct curr5t ( f #dj to #aaj volts is made to pass ?r\gh x1 ! curr5t is made & brok5 f #a1jjj to #aj1jjj times a m9ute4 ,by rais+ or l[]+ ! sleeve1 ?us expos+ m or less ( ! plat9um1 or alloy po9t1 ! numb] ( int]ruptions p] m9ute c be v>i$ at w4 ,z ! electrolytic int]rupt] w only op]ate 9 "o direction1 y mu/ connect x ) its plat9um1 or alloy anode1 to ! or positive p[] lead & ! lead ca?ode to ! - or negative p[] lead4 ,y c f9d out :i* is :i* by connect+ 9 ! int]rupt] & try+ x1 or y c use a pol>ity indicator4 ,an electrolytic int]rupt] c be b\ght = z little z #c4jj4 ,h[ to ,adju/ ,y\r ,transmitt]4 ,tun+ ,) a ,hot ,wire ,ammet]4--,a transmitt] c be tun$ 9 two diff]5t ways & ^! are3 7#a7 by adju/+ ! l5g? ( ! sp>k gap & ! tun+ coil s t ! greate/ am\nt ( en]gy is set up 9 ! oscillat+ circuits1 & 7#b7 by adju/+ ! app>atus s t x w s5d out waves ( a giv5 l5g?4 ,to adju/ ! transmitt] s t ! circuits w be 9 tune y %\ld h a hot wire ammet]1 or radiation ammet]1 z x is call$1 :i* is %[n 9 ,fig4 #bd4 ,x consi/s ( a ?9 plat9um wire ?r\gh :i* ! high-frequ5cy curr5ts surge & ^! heat x2 ! expansion & contraction ( ! wire moves a ne$le ov] a scale m>k$ (f into fractions ( an amp]e4 ,:5 ! sp>k gap & tun+ coil ( y\r set are prop]ly adju/$1 ! ne$le w sw+ f>!/ to ! "r ov] ! scale & y w !n "k t ! a]ial wire sy/em1 or op5 oscillation circuit1 & ! clos$ oscillation circuit are 9 tune & radiat+ ! greate/ am\nt ( en]gy4 ,illu/ration3 ,fig4 #bd4--,pr9ciple ( ! ,hot ,wire ,ammet]4 ,to ,s5d ,out a #bjj ,met] ,wave ,l5g?4--,if y are us+ a cond5s] hav+ a capacitance ( 4#jjg micr(>ad1 :i* is ! l>ge/ capacity value t ! ,gov]nm5t w all[ an amateur to use1 !n if y h a hot wire ammet] 9 y\r a]ial & tune ! inductance coil or coils until ! ammet] %[s ! l>ge/ am\nt ( en]gy fl[+ ?r\gh x y w "k t y\r transmitt] is tun$ & t ! a]ial is s5d+ out waves ^: l5g? is #bjj met]s4 ,to tune to diff]5t wave l5g?s y mu/ h a wave-met]4 ,! ,use ( ! ,a]ial ,swit*4--,:]e y int5d to in/all bo? a transmitt] & a receptor y w ne$ a ?r[ov] swit*1 or a]ial swit*1 z x is call$4 ,an ord9>y d\ble-pole1 d\ble-?r[ swit*1 z %[n at ,a 9 ,fig4 #be1 c be us$1 or a swit* made especially = ! purpose z at ,b is h&i] because ! arc ( ! ?r[ is mu* less4 ,illu/ration3 ,fig4 #be4--,k9ds ( ,a]ial ,swit*es4 ,a]ial ,swit* = a ,complete ,s5d+ & ,receiv+ ,set4--,y c buy a d\ble-pole1 d\ble-?r[ swit* m\nt$ on a porcela9 base = ab\t #ge c5ts & ?is w s]ve = ,set ,no4 #a4 ,screw ?is swit* on y\r table betwe5 ! s5d+ & receiv+ sets & !n connect "o ( ! middle po/s ( x ) ! gr\nd wire & ! o!r middle po/ ) ! lightn+ swit* :i* connects ) ! a]ial4 ,connect ! po/ ( ! tun+ coil ) "o ( ! end po/s ( ! swit* & ! clip ( ! tun+ coil ) ! o!r & complem5t>y po/ ( ! swit*4 ,?is done1 connect "o ( ! opposite end po/s ( ! swit* to ! po/ ( ! receiv+ tun+ coil & connect ! slid+ contact ( ! latt] ) ! o!r & complem5t>y po/ ( ! swit* z %[n 9 ,fig4 #bf4 ,illu/ration3 ,fig4 #bf4--,wir+ ,diagram = ,complete ,s5d+ & ,receiv+ ,set ,no4 #a4 ,connect+ 9 ! ,lightn+ ,swit*4--,! a]ial wire connects ) ! middle po/ ( ! lightn+ swit*1 :ile "o ( ! end po/s lead to "o ( ! middle po/s ( ! a]ial swit*4 ,! o!r end po/ ( ! lightn+ swit* leads to a sep>ate gr\nd outside ! build+1 z ! wir+ diagrams ,figs4 #bf & #bg %[4 ,illu/ration3 ,fig4 #bg4--,wir+ ,diagram = ,complete ,s5d+ & ,receiv+ ,set ,no4 #b4 ,,*apt] ,v ,,electricity ,,simply ,,expla9$ ,x is easy to und]/& h[ electricity behaves & :at x does if y get ! "r idea ( x at ! />t4 ,9 ! fir/ place1 if y w ?9k ( electricity z be+ a fluid l wat] its fundam5tal actions w be greatly simplifi$4 ,bo? wat] & electricity may be at re/ or 9 motion4 ,:5 at re/1 "u c]ta9 conditions1 ei!r "o w develop pressure1 & ?is pressure :5 releas$ w cause !m to fl[ ?r\gh _! respective conductors & ?us produce a curr5t4 ,electricity at ,re/ & 9 ,motion4--,any wire or a conductor ( any k9d c be *>g$ ) electricity1 b a ,leyd5 j>1 or o!r cond5s]1 is g5]ally us$ to hold an electric *>ge because x has a mu* l>g] capacitance1 z its capacity is call$1 ?an a wire4 ,z a simple analogue ( a cond5s]1 suppose y h a tank ( wat] rais$ above a second tank & t ^! are connect$ toge!r by means ( a pipe ) a valve 9 x1 z %[n at ,a 9 ,fig4 #bh4 ,illu/ration3 ,fig4 #bh4--,wat] ,analogue = ,electric ,pressure4 ,illu/ration3 orig9al ,und]wood & ,und]wood4 ,fir/ ,wireless ,college 9 ! ,_w1 at ,tufts ,college1 ,mass4 ,n[ if y fill ! upp] tank ) wat] & ! valve is turn$ (f1 no wat] c fl[ into ! l[] tank b !re is a diff]5ce ( pressure betwe5 !m1 & ! mom5t y turn ! valve on a curr5t ( wat] w fl[ ?r\gh ! pipe4 ,9 v mu* ! same way :5 y h a cond5s] *>g$ ) electricity ! latt] w be "u pressure1 t is1 a diff]5ce ( pot5tial w be set up1 = "o ( ! %eets ( metal w be *>g$ positively & ! o!r "o1 :i* is insulat$ f x1 w be *>g$ negatively1 z %[n at ,b4 ,on clos+ ! swit* ! opposite *>ges ru% toge!r & =m a curr5t :i* fl[s to & fro betwe5 ! metal plates4 ,footnote3 ,/rictly speak+ x is ! diff]5ce ( pot5tial t sets up ! electromotive =ce4 ,! ,electric ,curr5t & ,its ,circuit4--,j z wat] fl[+ ?r\gh a pipe has quantity & pressure back ( x & ! pipe (f]s friction to x :i* t5ds to hold back ! wat]1 s1 likewise1 does electricity fl[+ 9 a circuit h3 7#a7 quantity1 or curr5t /r5g?1 or j curr5t1 z x is call$ = %ort1 or amp]age1 & 7#b7 pressure1 or pot5tial diff]5ce1 or electromotive =ce1 or voltage1 z x is v>i\sly call$1 & ! wire1 or circuit1 9 :i* ! curr5t is fl[+ has 7#c7 resi/ance :i* t5ds to hold back ! curr5t4 ,a def9ite relation exi/s betwe5 ! curr5t & its electromotive =ce & also betwe5 ! curr5t1 electromotive =ce & ! resi/ance ( ! circuit2 & if y w get ?is relation%ip cle>ly 9 y\r m9d y w h a v good insight into h[ direct & alt]nat+ curr5ts act4 ,to keep a quantity ( wat] fl[+ 9 a loop ( pipe1 :i* we w call ! circuit1 pressure mu/ be appli$ to x & ?is may be done by a rot>y pump z %[n at ,a 9 ,fig4 #bi2 9 ! same way1 to keep a quantity ( electricity fl[+ 9 a loop ( wire1 or circuit1 a batt]y1 or o!r means = g5]at+ electric pressure mu/ be us$1 z %[n at ,b4 ,illu/ration3 ,fig4 #bi4--,wat] ,analogues = ,direct & ,alt]nat+ ,curr5ts4 ,if y h a clos$ pipe connect$ ) a pi/on pump1 z at ,c1 z ! pi/on moves to & fro ! wat] 9 ! pipe w move fir/ "o way & !n ! o!r4 ,s also :5 an alt]nat+ curr5t g5]ator is connect$ to a wire circuit1 z at ,d1 ! curr5t w fl[ fir/ 9 "o direction & !n 9 ! o!r1 & ?is is :at is call$ an alt]nat+ curr5t4 ,curr5t & ! ,amp]e4--,! am\nt ( wat] fl[+ 9 a clos$ pipe is ! same at all p>ts ( x & ?is is also true ( an electric curr5t1 9 t !re is exactly ! same quantity ( electricity at "o po9t ( ! circuit z !re is at any o!r4 ,! am\nt ( electricity1 or curr5t1 fl[+ 9 a circuit 9 a second is measur$ by a unit call$ ! amp]e1 ,footnote3 ,= def9ition ( amp]e see ,app5dix4 & x is express$ by ! symbol ,i4 ,footnote3 ,?is is because ! lett] ,c is us$ = ! symbol ( capacitance ,j to give y an idea ( ! quantity ( curr5t an amp]e is we w say t a dry cell :5 fre% gives a curr5t ( ab\t #bj amp]es4 ,to measure ! curr5t 9 amp]es an in/rum5t call$ an ammet] is us$1 z %[n at ,a 9 ,fig4 #cj1 & ?is is always connect$ 9 s]ies ) ! l9e1 z %[n at ,b4 ,illu/ration3 ,fig4 #cj4--;,h[ ! ,ammet] & ,voltmet] are ,us$4 ,electromotive ,=ce & ! ,volt4--,:5 y h a pipe fill$ ) wat] or a circuit *>g$ ) electricity & y want to make !m fl[ y mu/ use a pump 9 ! fir/ case & a batt]y or a dynamo 9 ! second case4 ,x is ! batt]y or dynamo t sets up ! electric pressure z ! circuit itself is always *>g$ ) electricity4 ,! m cells y connect toge!r 9 s]ies ! great] w be ! electric pressure develop$ & ! m curr5t x w move along j z ! am\nt ( wat] fl[+ 9 a pipe c be increas$ by increas+ ! pressure ( ! pump4 ,! unit ( electromotive =ce is ! volt1 & ?is is ! electric pressure :i* w =ce a curr5t ( #a amp]e ?r\gh a resi/ance ( #a ohm2 x is express$ by ! symbol ,e4 ,a fre% dry cell w deliv] a curr5t ( ab\t #a4e volts4 ,to measure ! pressure ( a curr5t 9 volts an in/rum5t call$ a voltmet] is us$1 z %[n at ,c 9 ,fig4 #cj1 & ?is is always connect$ across ! circuit1 z %[n at ,d4 ,resi/ance & ! ,ohm4--,j z a wat] pipe (f]s a c]ta9 am\nt ( resi/ance to ! fl[ ( wat] ?r\gh x1 s a circuit opposes ! fl[ ( electricity 9 x & ?is is call$ resi/ance4 ,fur!r1 9 ! same way t a small pipe w n all[ a l>ge am\nt ( wat] to fl[ ?r\gh x1 s1 too1 a ?9 wire limits ! fl[ ( ! curr5t 9 x4 ,if y connect a resi/ance coil 9 a circuit x acts 9 ! same way z p>tly clos+ ! valve 9 a pipe1 z %[n at ,a & ,b 9 ,fig4 #ca4 ,! resi/ance ( a circuit is measur$ by a unit call$ ! ohm1 & x is express$ by ! symbol ,r4 ,a ,no4 #aj1 ,br[n & ,%>pe gauge s(t copp] wire1 #a1jjj feet long1 has a resi/ance ( ab\t #a ohm4 ,to measure ! resi/ance ( a circuit an app>atus call$ a resi/ance bridge is us$4 ,! resi/ance ( a circuit c1 h[ev]1 be easily calculat$1 z ! foll[+ %[s4 ,illu/ration3 ,fig4 #ca4--,wat] ,valve ,analogue ( ,electric ,resi/ance4 ,a- a valve limits ! fl[ ( wat]4 ,b- a resi/ance limits ! fl[ ( curr5t4 ,:at ,ohm's ,law ,is4--,if1 n[1 7#a7 y "k :at ! curr5t fl[+ 9 a circuit is 9 amp]es1 & ! electromotive =ce1 or pressure1 is 9 volts1 y c !n easily f9d :at ! resi/ance is 9 ohms ( ! circuit 9 :i* ! curr5t is fl[+ by ?is =mula3 ,volts ,e --------- ,ohms1 or --- ,r ,amp]es ,i ,t is1 if y divide ! curr5t 9 amp]es by ! electromotive =ce 9 volts ! quoti5t w give y ! resi/ance 9 ohms4 ,or 7#b7 if y "k :at ! electromotive =ce ( ! curr5t is 9 volts & ! resi/ance ( ! circuit is 9 ohms !n y c f9d :at ! curr5t fl[+ 9 ! circuit is 9 amp]es1 ?us3 ,volts ,e ----- ,amp]es1 or --- ,i ,ohms ,r ,t is1 by divid+ ! resi/ance ( ! circuit 9 ohms1 by ! electromotive =ce ( ! curr5t y w get ! amp]es fl[+ 9 ! circuit4 ,f9ally 7#c7 if y "k :at ! resi/ance ( ! circuit is 9 ohms & ! curr5t is 9 amp]es !n y c f9d :at ! electromotive =ce is 9 volts s9ce3 ,ohms x ,amp]es ,volts1 or ,r x ,i ,e ,t is1 if y multiply ! resi/ance ( ! circuit 9 ohms by ! curr5t 9 amp]es ! result w give y ! electromotive =ce 9 volts4 ,f ?is y w see t if y "k ! value ( any two ( ! con/ants y c f9d ! value ( ! unkn[n con/ant by a simple ari?metical process4 ,?is relation betwe5 ^! ?ree con/ants is kn[n z ,ohm's ,law & z !y are v important y %\ld memorize !m4 ,:at ! ,watt & ,kil[att ,are4--,j z horsep[] or ,h4,p41 is ! unit ( "w t /eam has done or c d1 s ! watt is ! unit ( "w t an electric curr5t has done or c d4 ,to f9d ! watts a curr5t develops y ne$ only to multiply ! amp]es by ! volts4 ,!re are #gdf watts to #a horsep[]1 & #a1jjj watts are equal to #a kil[att4 ,electromagnetic ,induction4--,to %[ t a curr5t ( electricity sets up a magnetic field ar\nd x y h only to hold a compass ov] a wire ^: ends are connect$ ) a batt]y :5 ! ne$le w sw+ at "r angles to ! l5g? ( ! wire4 ,by w9d+ an insulat$ wire into a coil & connect+ ! ends ( ! latt] ) a batt]y y w f9d1 if y te/ x ) a compass1 t ! coil is magnetic4 ,?is is due to ! fact t ! en]gy ( an electric curr5t fl[+ 9 ! wire is p>tly *ang$ into magnetic l9es ( =ce :i* rotate at "r angles ab\t x z %[n at ,a 9 ,fig4 #cb4 ,! magnetic field produc$ by ! curr5t fl[+ 9 ! coil is precisely ! same z t set up by a p]man5t /eel magnet4 ,conv]sely1 :5 a magnetic l9e ( =ce is set up a "p ( its en]gy goes to make up electric curr5ts :i* :irl ab\t 9 a l mann]1 z %[n at ,b4 ,illu/ration3 7,a7 & 7,b7 ,fig4 #cb4--;,h[ an ,electric ,curr5t is ,*ang$ into ,magnetic ,l9es ( ,=ce & ,^! into an ,electric ,curr5t4 ,illu/ration3 7,c7 & 7,d7 ,fig4 #cb4--;,h[ an ,electric ,curr5t ,sets up a ,magnetic ,field4 ,self-induction or ,inductance4--,:5 a curr5t is made to fl[ 9 a coil ( wire ! magnetic l9es ( =ce produc$ are conc5trat$1 z at ,c1 j z a l5s conc5trates rays ( light1 & ?is =ms an int5se magnetic field1 z x is call$4 ,n[ if a b> ( s(t iron is br\ght close to "o end ( ! coil ( wire1 or1 bett] /ill1 if x is pu%$ into ! coil1 x w be magnetiz$ by electromagnetic induction1 see ,d1 & x w rema9 a magnet until ! curr5t is cut (f4 ,mutual ,induction4--,:5 two loops ( wire1 or bett]1 two coils ( wire1 are plac$ close toge!r ! electromagnetic induction betwe5 !m is reactive1 t is1 :5 a curr5t is made to fl[ ?r\gh "o ( ! coils clos$ magnetic l9es ( =ce are set up & :5 ^! cut ! o!r loop or turns ( wire ( ! o!r coil1 !y 9 turn produce electric curr5ts 9 x4 ,x is ! mutual induction t takes place betwe5 two coils ( wire :i* makes x possible to trans=m l[ voltage curr5ts f a batt]y or a #aaj volt s\rce ( curr5t into high pressure curr5ts1 or high pot5tial curr5ts1 z !y are call$1 by means ( a sp>k coil or a trans=m]1 z well z to /ep up & /ep d[n ! pot5tial ( ! high frequ5cy curr5ts t are set up 9 s5d+ & receiv+ oscillation trans=m]s4 ,s(t iron cores are n us$ 9 oscillation inductance coils & oscillation trans=m]s = ! reason t ! frequ5cy ( ! curr5t is s high ! iron w\ld n h "t to magnetize & demagnetize & s w\ld n help along ! mutual induction to any appreciable ext5t4 ,high-,frequ5cy ,curr5ts4--,high frequ5cy curr5ts1 or electric oscillations z !y are call$1 are curr5ts ( electricity t surge to & fro 9 a circuit a million times1 m or less1 p] second4 ,curr5ts ( su* high frequ5cies w oscillate1 t is1 surge to & fro1 9 an op5 circuit1 su* z an a]ial wire sy/em1 z well z 9 a clos$ circuit4 ,n[ !re is only "o me?od by :i* curr5ts ( high frequ5cy1 or radio-frequ5cy1 z !y are t]m$1 c be set up by sp>k transmitt]s1 & ?is is by dis*>g+ a *>g$ cond5s] ?r\gh a circuit hav+ a small resi/ance4 ,to *>ge a cond5s] a sp>k coil or a trans=m] is us$ & ! ends ( ! second>y coil1 :i* deliv]s ! high pot5tial alt]nat+ curr5t1 are connect$ ) ! cond5s]4 ,to dis*>ge ! cond5s] automatically a sp>k1 or an arc1 or ! fl[ ( electrons 9 a vacuum tube1 is employ$4 ,con/ants ( an ,oscillation ,circuit4--,an oscillation circuit1 z po9t$ out be=e1 is "o 9 :i* high frequ5cy curr5ts surge or oscillate4 ,n[ ! numb] ( times a high frequ5cy curr5t w surge =? & back 9 a circuit dep5ds ^u ?ree factors ( ! latt] & ^! are call$ ! con/ants ( ! circuit1 namely3 7#a7 its capacitance1 7#b7 its inductance & 7#c7 its resi/ance4 ,:at ,capacitance ,is4--,! ^w capacitance means ! electro/atic capacity ( a cond5s] or a circuit4 ,! capacitance ( a cond5s] or a circuit is ! quantity ( electricity :i* w raise its pressure1 or pot5tial1 to a giv5 am\nt4 ,! capacitance ( a cond5s] or a circuit dep5ds on its size & =m & ! voltage ( ! curr5t t is *>g+ x4 ,! capacitance ( a cond5s] or a circuit is directly proportional to ! quantity ( electricity t w keep ! *>ge at a giv5 pot5tial4 ,! f>ad1 ^: symbol is ,m1 is ! unit ( capacitance & a cond5s] or a circuit to h a capacitance ( "o f>ad mu/ be ( su* size t "o c\lomb1 :i* is ! unit ( electrical quantity1 w raise its *>ge to a pot5tial ( "o volt4 ,s9ce ! f>ad is f> too l>ge = practical purposes a million? ( a f>ad1 or micr(>ad1 ^: symbol is mfd41 is us$4 ,:at ,inductance ,is4--,"u ! sub-caption ( ,self-induction & ,inductance 9 ! beg9n+ ( ?is *apt] x 0 %[n t x 0 ! inductance ( a coil t makes a curr5t fl[+ ?r\gh x produce a /rong magnetic field1 & "h1 z "o ( ! con/ants ( an oscillation circuit1 x makes a high-frequ5cy curr5t act z ?\gh x possess$ in]tia4 ,in]tia is t prop]ty ( a mat]ial body t requires "t & en]gy to set 9 motion1 or /op4 ,inductance is t prop]ty ( an oscillation circuit t makes an electric curr5t take "t to />t & "t to /op4 ,because ( ! inductance1 :5 a curr5t fl[s ?r\gh a circuit x causes ! electric en]gy to be absorb$ & *anges a l>ge "p ( x into magnetic l9es ( =ce4 ,:]e high frequ5cy curr5ts surge 9 a circuit ! inductance ( x becomes a p[]ful factor4 ,! practical unit ( inductance is ! h5ry & x is repres5t$ by ! symbol ,l4 ,:at ,resi/ance ,is4--,! resi/ance ( a circuit to high-frequ5cy curr5ts is diff]5t f t = l[ voltage direct or alt]nat+ curr5ts1 z ! =m] d n s9k into ! conductor to ne>ly s great an ext5t2 9 fact1 !y /ick practically to ! surface ( x1 & h5ce _! fl[ is oppos$ to a v mu* great] ext5t4 ,! resi/ance ( a circuit to high frequ5cy curr5ts is g5]ally f\nd 9 ! sp>k gap1 arc gap1 or ! space betwe5 ! electrodes ( a vacuum tube4 ,! unit ( resi/ance is1 z /at$1 ! ohm1 & its symbol is ,r4 ,! ,effect ( ,capacitance1 ,inductance & ,resi/ance on ,electric ,oscillations4--,if an oscillation circuit 9 :i* high frequ5cy curr5ts surge has a l>ge resi/ance1 x w s oppose ! fl[ ( ! curr5ts t !y w be damp$ out & rea* z]o gradually1 z %[n at ,a 9 ,fig4 #cc4 ,b if ! resi/ance ( ! circuit is small1 & 9 wireless circuits x is usually s small z to be negligible1 ! curr5ts w oscillate1 until _! en]gy is damp$ out by radiation & o!r losses1 z %[n at ,b4 ,illu/ration3 ,fig4 #cc4--,! ,effect ( ,resi/ance on ! ,dis*>ge ( an ,electric ,curr5t4 ,z ! capacitance & ! inductance ( ! circuit1 :i* may be made ( any value1 t is am\nt1 y wi%1 det]m9es ! "t p]iod1 t is1 ! l5g? ( "t = a curr5t to make "o complete oscillation1 x mu/ be cle> t by v>y+ ! values ( ! cond5s] & ! inductance coil y c make ! high frequ5cy curr5t oscillate z fa/ or z sl[ z y wi% )9 c]ta9 limits4 ,:]e ! electric oscillations t are set up are v fa/1 ! waves s5t out by ! a]ial w be %ort1 &1 conv]sely1 :]e ! oscillations are sl[ ! waves emitt$ w be long4 ,,*apt] ,,vi ,,h[ ,,! ,,transmitt+ ,,& ,,receiv+ ,,sets ,,"w ,! easie/ way to get a cle> conception ( h[ a wireless transmitt] s5ds out electric waves & h[ a wireless receptor receives !m is to take ea* "o sep>ately & foll[3 7#a7 9 ! case ( ! transmitt]1 ! trans=mation ( ! l[ voltage direct1 or alt]nat+ curr5t into high pot5tial alt]nat+ curr5ts2 !n f9d out h[ ^! *>ge ! cond5s]1 h[ ?is is dis*>g$ by ! sp>k gap & sets up high-frequ5cy curr5ts 9 ! oscillation circuits2 !n 7#b7 9 ! case ( ! receptor1 to foll[ ! high frequ5cy curr5ts t are set up 9 ! a]ial wire & le>n h[ !y are trans=m$ into oscillations ( l[] pot5tial :5 !y h a l>g] curr5t /r5g?1 h[ ^! are conv]t$ into int]mitt5t direct curr5ts by ! detector & :i* !n fl[ into & op]ate ! telephone receiv]4 ,h[ ,transmitt+ ,set ,no4 #a ,works4 ,! ,batt]y & ,sp>k ,coil ,circuit4--,:5 y press d[n on ! knob ( ! key ! silv] po9ts ( x make contact & ?is closes ! circuit2 ! l[ voltage direct curr5t f ! batt]y n[ fl[s ?r\gh ! prim>y coil ( ! sp>k coil & ?is magnetizes ! s(t iron core4 ,! in/ant x becomes magnetic x pulls ! spr+ ( ! vibrator ov] to x & ?is breaks ! circuit2 :5 ?is takes place ! curr5t /ops fl[+ ?r\gh ! prim>y coil2 ?is causes ! core to lose its magnetism :5 ! vibrator spr+ flies back & aga9 makes contact ) ! adju/+ screw2 !n ! cycle ( op]ations is repeat$4 ,a cond5s] is connect$ across ! contact po9ts ( ! vibrator s9ce ?is gives a mu* high] voltage at ! ends ( ! second>y coil ?an :]e ! coil is us$ )\t x2 ?is is because3 7#a7 ! self-induction ( ! prim>y coil makes ! pressure ( ! curr5t rise & :5 ! contact po9ts close ! circuit aga9 x dis*>ges ?r\gh ! prim>y coil1 & 7#b7 :5 ! break takes place ! curr5t fl[s into ! cond5s] in/ead ( arc+ across ! contact po9ts4 ,*ang+ ! ,prim>y ,sp>k ,coil ,curr5t ,into ,second>y ,curr5ts4--,n[ e "t ! vibrator contact po9ts close ! prim>y circuit ! electric curr5t 9 ! prim>y coil is *ang$ into clos$ magnetic l9es ( =ce & z ^! cut ?r\gh ! second>y coil !y set up 9 x a mom5t>y curr5t 9 "o direction4 ,!n ! in/ant ! vibrator po9ts break ap>t ! prim>y circuit is op5$ & ! clos$ magnetic l9es ( =ce contract & z !y d s !y cut ! turns ( wire 9 ! second>y coil 9 ! opposite direction & ?is sets up ano!r mom5t>y curr5t 9 ! second>y coil 9 ! o!r direction4 ,! result is t ! l[ voltage direct curr5t ( ! batt]y is *ang$ into alt]nat+ curr5ts ^: frequ5cy is precisely t ( ! spr+ vibrator1 b :ile ! frequ5cy ( ! curr5ts is l[ _! pot5tial1 or voltage1 is enorm\sly increas$4 ,:at ,ratio ( ,trans=mation ,means4--,to make a sp>k coil /ep up ! l[ voltage direct curr5t into high pot5tial alt]nat+ curr5t ! prim>y coil is w\nd ) a c\ple ( lay]s ( ?ick insulat$ copp] wire & ! second>y is w\nd ) a ?\s&1 m or less1 numb] ( turns ) v f9e insulat$ copp] wire4 ,if ! prim>y & second>y coils 7 w\nd ) ! same numb] ( turns ( wire !n ! pressure1 or voltage1 ( ! second>y coil at its t]m9als w\ld be ! same z t ( ! curr5t :i* fl[$ ?r\gh ! prim>y coil4 ,"u ^! conditions ! ratio ( trans=mation1 z x is call$1 w\ld be unity4 ,! ratio ( trans=mation is directly proportional to ! numb] ( turns ( wire on ! prim>y & second>y coils &1 s9ce ?is is ! case1 if y w9d #aj turns ( wire on ! prim>y coil & #a1jjj turns ( wire on ! second>y coil !n y w get #ajj times z high a pressure1 or voltage1 at ! t]m9als ( ! second>y z t :i* y caus$ to fl[ ?r\gh ! prim>y coil1 b1 naturally1 ! curr5t /r5g?1 or amp]age1 w be proportionately decreas$4 ,! ,second>y ,sp>k ,coil ,circuit4--,?is includes ! second>y coil & ! sp>k gap :i* are connect$ toge!r4 ,:5 ! alt]nat+1 b high pot5tial1 curr5ts :i* are develop$ by ! second>y coil1 rea* ! balls1 or electrodes1 ( ! sp>k gap ! latt] are alt]nately *>g$ positively & negatively4 ,n[ take a giv5 in/ant :5 "o electrode is *>g$ positively & ! o!r "o is *>g$ negatively1 !n :5 !y are *>g$ to a high en\gh pot5tial ! electric /ra9 breaks d[n ! air gap betwe5 !m & ! two *>ges ru% toge!r z describ$ 9 ! *apt] be=e ?is "o 9 connection ) ! dis*>ge ( a cond5s]4 ,:5 ! *>ges ru% toge!r !y =m a curr5t :i* burns out ! air 9 ! gap & ?is gives rise to ! sp>k1 & z ! heat$ gap betwe5 ! two electrodes is a v good conductor ! electric curr5t surges =? & back ) high frequ5cy1 p]haps a doz5 times1 be=e ! air replaces t :i* has burn$ out4 ,x is ! inru%+ air to fill ! vacuum ( ! gap t makes ! crackl+ noise :i* accompanies ! dis*>ge ( ! electric sp>k4 ,9 ?is way !n electric oscillations ( ! ord] ( a million1 m or less1 are produc$ & if an a]ial & a gr\nd wire are connect$ to ! sp>k balls1 or electrodes1 ! oscillations w surge up & d[n x & ! en]gy ( ^! 9 turn1 are *ang$ into electric waves :i* travel out into space4 ,an op5 circuit transmitt] ( ?is k9d w s5d out waves t are f\r times z long z ! a]ial itself1 b z ! waves x s5ds out are /rongly damp$ ! ,gov]nm5t w n p]mit x to be us$4 ,! ,clos$ ,oscillation ,circuit4--,by us+ a clos$ oscillation circuit ! transmitt] c be tun$ to s5d out waves ( a giv5 l5g? & :ile ! waves are n s /rongly damp$ m curr5t c be s5t into ! a]ial wire sy/em4 ,! clos$ oscillation circuit consi/s (3 7#a7 a sp>k gap1 7#b7 a cond5s] & 7#c7 an oscillation trans=m]4 ,! high pot5tial alt]nat+ curr5t deliv]$ by ! second>y coil n only *>ges ! sp>k gap electrodes :i* necess>ily h a v small capacitance1 b x *>ges ! cond5s] :i* has a l>ge capacitance & ! value ( :i* c be *ang$ at w4 ,n[ :5 ! cond5s] is fully *>g$ x dis*>ges ?r\gh ! sp>k gap & !n ! electric oscillations set up surge to & fro ?r\gh ! clos$ circuit4 ,z a clos$ circuit is a v poor radiator ( en]gy1 t is1 ! electric oscillations are n freely conv]t$ into electric waves by x1 !y surge up to1 & ?r\gh ! a]ial wire2 n[ z ! a]ial wire is a good radiator ne>ly all ( ! en]gy ( ! electric oscillations :i* surge ?r\gh x are conv]t$ into electric waves4 ,h[ ,transmitt+ ,set ,no4 #b ,works4 ,) ,alt]nat+ ,curr5t4 ,! op]ation ( a transmitt+ set t uses an alt]nat+ curr5t trans=m]1 or p[] trans=m]1 z x is sometimes call$1 is ev5 m simple ?an "o us+ a sp>k coil4 ,! trans=m] ne$s no vibrator :5 us$ ) alt]nat+ curr5t4 ,! curr5t f a g5]ator fl[s ?r\gh ! prim>y coil ( ! trans=m] & ! alt]nations ( ! usual light+ curr5t is #fj cycles p] second4 ,?is curr5t sets up an alt]nat+ magnetic field 9 ! core ( ! trans=m] & z ^! magnetic l9es ( =ce exp& & contract !y set up alt]nat+ curr5ts ( ! same frequ5cy b ( mu* high] voltage at ! t]m9als ( ! second>y coil accord+ to ! ratio ( ! prim>y & second>y turns ( wire z expla9$ "u ! sub-caption ( ,ratio ( ,trans=mation4 ,) ,direct ,curr5t4--,:5 a #aaj volt direct curr5t is us$ to en]gize ! p[] trans=m] an electrolytic int]ruptor is ne$$ to make & break ! prim>y circuit1 j z a vibrator is ne$$ = ! same purpose ) a sp>k coil4 ,:5 ! electrodes are connect$ 9 s]ies ) ! prim>y coil ( a trans=m] & a s\rce ( direct curr5t hav+ a pot5tial ( #dj to #aaj volts1 bubbles ( gas are =m$ on ! end ( ! plat9um1 or alloy anode1 :i* prev5t ! curr5t f fl[+ until ! bubbles break & !n ! curr5t fl[s aga91 9 ?is way ! curr5t is rapidly made & brok5 & ! break is v %>p4 ,:]e ?is type ( int]rupt] is employ$ ! cond5s] t is usually %unt$ ar\nd ! break is n necess>y z ! int]rupt] itself has a c]ta9 inh]5t capacitance1 due to electrolytic action1 & :i* is call$ its electrolytic capacitance1 & ?is is l>ge en\gh to balance ! self-induction ( ! circuit s9ce ! great] ! numb] ( breaks p] m9ute ! small] ! capacitance requir$4 ,! ,rot>y ,sp>k ,gap4--,9 ?is type ( sp>k gap ! two fix$ electrodes are connect$ ) ! t]m9als ( ! second>y coil ( ! p[] trans=m] & also ) ! cond5s] & prim>y ( ! oscillation trans=m]4 ,n[ :5ev] any pair ( electrodes on ! rotat+ disk are 9 a l9e ) ! pair ( fix$ electrodes a sp>k w take place1 h5ce ! pit* ( ! note dep5ds on ! spe$ ( ! motor driv+ ! disk4 ,?is k9d ( a rot>y sp>k-gap is call$ non-syn*ron\s & x is g5]ally us$ :]e a #fj cycle alt]nat+ curr5t is available b x w "w ) o!r high] frequ5cies4 ,! ,qu5*$ ,sp>k ,gap4--,if y /rike a piano /r+ a s+le quick bl[ x w cont9ue to vibrate accord+ to its natural p]iod4 ,?is is v mu* ! way 9 :i* a qu5*$ sp>k gap sets up oscillations 9 a c\pl$ clos$ & op5 circuit4 ,! oscillations set up 9 ! prim>y circuit by a qu5*$ sp>k make only ?ree or f\r %>p sw+s & 9 s do+ transf] all ( _! en]gy ov] to ! second>y circuit1 :]e x w oscillate "s fifty times or m be=e x is damp$ out1 because ! high frequ5cy curr5ts are n =c$1 b simply oscillate to ! natural frequ5cy ( ! circuit4 ,= ?is reason ! radiat$ waves approa* some:at ! condition ( cont9u\s waves1 & s %>p] tun+ is possible4 ,! ,oscillation ,trans=m]4--,9 ?is set ! cond5s] 9 ! clos$ circuit is *>g$ & dis*>g$ & sets up oscillations t surge ?r\gh ! clos$ circuit z 9 ,set ,no4 #a4 ,9 ?is set1 h[ev]1 an oscillation trans=m] is us$ & z ! prim>y coil ( x is includ$ 9 ! clos$ circuit ! oscillations set up 9 x produce /rong oscillat+ magnetic l9es ( =ce4 ,! magnetic field ?us produc$ sets up 9 turn electric oscillations 9 ! second>y coil ( ! oscillation trans=m] & ^! surge ?r\gh ! a]ial wire sy/em :]e _! en]gy is radiat$ 9 ! =m ( electric waves4 ,! great advantage ( us+ an oscillation trans=m] in/ead ( a simple inductance coil is t ! capacitance ( ! clos$ circuit c be v mu* l>g] ?an t ( ! a]ial wire sy/em4 ,?is p]mits m en]gy to be /or$ up by ! cond5s] & ?is is impress$ on ! a]ial :5 x is radiat$ z electric waves4 ,h[ ,receiv+ ,set ,no4 ,i ,works4--,:5 ! electric waves f a di/ant s5d+ /ation imp+e on ! wire ( a receiv+ a]ial _! en]gy is *ang$ into electric oscillations t are ( exactly ! same frequ5cy 7assum+ ! receptor is tun$ to ! transmitt]7 b ^: curr5t /r5g? 7amp]age7 & pot5tial 7voltage7 are v small4 ,^! electric waves surge ?r\gh ! clos$ circuit b :5 !y rea* ! cry/al detector ! contact ( ! metal po9t on ! cry/al p]mits m curr5t to fl[ ?r\gh x 9 "o direction ?an x w all[ to pass 9 ! o!r direction4 ,= ?is reason a cry/al detector is sometimes call$ a rectifi]1 :i* x really is4 ,?us ! high frequ5cy curr5ts :i* ! /eel magnet cores ( ! telephone receiv] w\ld *oke (f are *ang$ by ! detector into int]mitt5t direct curr5ts :i* c fl[ ?r\gh ! magnet coils ( ! telephone receiv]4 ,s9ce ! telephone receiv] *okes (f ! oscillations1 a small cond5s] c be %unt$ ar\nd x s t a complete clos$ oscillation circuit is =m$ & ?is gives bett] results4 ,:5 ! int]mitt5t rectifi$ curr5t fl[s ?r\gh ! coils ( ! telephone receiv] x en]gizes ! magnet z long z x la/s1 :5 x is de-en]giz$2 ?is causes ! s(t iron disk1 or diaphragm z x is call$1 :i* sets close to ! ends ( ! poles ( ! magnet1 to vibrate2 & ?is 9 turn gives =? s\nds su* z dots & da%es1 spee* or music1 accord+ to ! nature ( ! electric waves t s5t !m out at ! di/ant /ation4 ,h[ ,receiv+ ,set ,no4 #b ,works4--,:5 ! electric oscillations t are set up by ! incom+ electric waves on ! a]ial wire surge ?r\gh ! prim>y coil ( ! oscillation trans=m] !y produce a magnetic field & z ! l9es ( =ce ( ! latt] cut ! second>y coil1 oscillations ( ! same frequ5cy are set up 9 x4 ,! pot5tial 7voltage7 ( ^! oscillations are1 h[ev]1 /epp$ d[n 9 ! second>y coil &1 h5ce1 _! curr5t /r5g? 7amp]es7 is increas$4 ,! oscillations !n fl[ ?r\gh ! clos$ circuit :]e !y are rectifi$ by ! cry/al detector & trans=m$ into s\nd waves by ! telephone receiv] z describ$ 9 connection ) ,set ,no4 #a4 ,! v>iable cond5s] %unt$ across ! clos$ circuit p]mits f9] second>y tun+ to be done ?an is possible )\t x4 ,:]e y are receiv+ cont9u\s waves f a wireless telephone transmitt] 7spee* or music7 y h to tune %>p] ?an is possible ) ! tun+ coil alone & to d ?is a v>iable cond5s] connect$ 9 p>allel ) ! second>y coil is necess>y4 ,,*apt] ,,vii ,,me*anical ,,& ,,electrical ,,tun+ ,!re is a /rik+ly close resemblance betwe5 s\nd waves & ! way !y are set up 9 ! air by a me*anically vibrat+ body1 su* z a /eel spr+ or a tun+ =k1 & electric waves & ! way !y are set up 9 ! e!r by a curr5t oscillat+ 9 a circuit4 ,z x is easy to grasp ! way t s\nd waves are produc$ & behave some?+ w be told ab\t !m 9 ?is *apt] & also an explanation ( h[ electric waves are produc$ & behave & ?us y w be able to get a cle> und]/&+ ( !m & ( tun+ 9 g5]al4 ,damp$ & ,su/a9$ ,me*anical ,vibrations4--,if y w place "o end ( a flat /eel spr+ 9 a vice & screw x up tight z %[n at ,a 9 ,fig4 #cd1 & !n pull ! free end ov] & let x g x w vibrate to & fro ) decreas+ amplitude until x comes to re/ z %[n at ,b4 ,:5 y pull ! spr+ ov] y /ore up en]gy 9 x & :5 y let x g ! /or$ up en]gy is *ang$ into en]gy ( motion & ! spr+ moves =? & back1 or vibrates z we call x1 until all ( its /or$ up en]gy is sp5t4 ,illu/ration3 ,fig4 #cd4--;,damp$ & ,su/a9$ ,me*anical ,vibrations4 ,if x 7 n = ! air surr\nd+ x & o!r frictional losses1 ! spr+ w\ld vibrate = a v long "t z ! /or$ up en]gy & ! en]gy ( motion w\ld practically (fset ea* o!r & s ! en]gy w\ld n be us$ up4 ,b z ! spr+ beats ! air ! latt] is s5t out 9 impulses & ! conv]sion ( ! vibrations ( ! spr+ into waves 9 ! air soon uses up ! en]gy y h imp>t$ to x & x comes to re/4 ,9 ord] to s5d out cont9u\s waves 9 ! air in/ead ( damp$ waves z ) a flat /eel spr+ y c use an electric driv5 tun+ =k1 see ,c1 9 :i* an electromagnet is fix$ on ! inside ( ! prongs & :5 ?is is en]giz$ by a batt]y curr5t ! vibrations ( ! prongs ( ! =k are kept go+1 or are su/a9$1 z %[n 9 ! diagram at ,d4 ,damp$ & ,su/a9$ ,electric ,oscillations4--,! vibrat+ /eel spr+ describ$ above is a v good analogue ( ! way t damp$ electric oscillations :i* surge 9 a circuit set up & s5d out p]iodic electric waves 9 ! e!r :ile ! electric driv5 tun+ =k j describ$ is likewise a good analogue ( h[ su/a9$ oscillations surge 9 a circuit & set up & s5d out cont9u\s electric waves 9 ! e!r z ! foll[+ %[s4 ,n[ ! inductance & resi/ance ( a circuit su* z is %[n at ,a 9 ,fig4 #ce1 sl[s d[n1 & f9ally damps out entirely1 ! electric oscillations ( ! high frequ5cy curr5ts1 see ,b1 :]e ^! are set up by ! p]iodic dis*>ge ( a cond5s]1 precisely z ! vibrations ( ! spr+ are damp$ out by ! friction ( ! air & o!r resi/ances t act ^u x4 ,z ! electric oscillations surge to & fro 9 ! circuit x is oppos$ by ! action ( ! e!r :i* surr\nds x & electric waves are set up 9 & s5t out ?r\gh x & ?is trans=mation soon uses up ! en]gy ( ! curr5t t fl[s 9 ! circuit4 ,illu/ration3 ,fig4 #ce4--;,damp$ & ,su/a9$ ,electric ,oscillations4 ,to s5d out cont9u\s waves 9 ! e!r su* z are ne$$ = wireless telephony in/ead ( damp$ waves :i* are1 at ! pres5t writ+1 g5]ally us$ = wireless telegraphy1 an electric oscillation arc or a vacuum tube oscillator mu/ be us$1 see ,c1 in/ead ( a sp>k gap4 ,:]e a sp>k gap is us$ ! cond5s] 9 ! circuit is *>g$ p]iodically & ) consid]able lapses ( "t betwe5 ea* ( ! *>g+ processes1 :51 ( c\rse1 ! cond5s] dis*>ges p]iodically & ) ! same "t elem5t betwe5 !m4 ,:]e an oscillation arc or a vacuum tube is us$ ! cond5s] is *>g$ z rapidly z x is dis*>g$ & ! result is ! oscillations are su/a9$ z %[n at ,d4 ,ab\t ,me*anical ,tun+4--,a tun+ =k is bett] ?an a spr+ or a /raight /eel b> = sett+ up me*anical vibrations4 ,z a matt] ( fact a tun+ =k is simply a /eel b> b5t 9 ! middle s t ! two ends are p>allel4 ,a h&le is atta*$ to middle po9t ( ! =k s t x c be held easily & :i* also all[s x to vibrate freely1 :5 ! ends ( ! prongs alt]nately approa* & rec$e f "o ano!r4 ,:5 ! prongs vibrate ! h&le vibrates up & d[n 9 unison ) x1 & imp>ts its motion to ! s\nd+ box1 or resonance case z x is sometimes call$1 :]e "o is us$4 ,if1 n[1 y w m\nt ! =k on a s\nd+ box :i* is tun$ s t x w be 9 resonance ) ! vibrations ( ! =k !re w be a direct re9=cem5t ( ! vibrations :5 ! note emitt$ by x w be augm5t$ 9 /r5g? & quality4 ,?is is call$ simple resonance4 ,fur!r1 if y m\nt a pair ( =ks1 ea* on a sep>ate s\nd+ box1 & h ! =ks ( ! same size1 tone & pit*1 & ! boxes syn*roniz$1 t is1 tun$ to ! same frequ5cy ( vibration1 !n set ! two boxes a foot or s ap>t1 z %[n at ,a 9 ,fig4 #cf1 :5 y /rike "o ( ! =ks ) a rubb] hamm] x w vibrate ) a def9ite frequ5cy &1 h5ce1 s5d out s\nd waves ( a giv5 l5g?4 ,:5 ! latt] /rike ! second =k ! impact ( ! molecules ( air ( :i* ! s\nd waves are =m$ w set its prongs to vibrat+ & x w1 9 turn1 emit s\nd waves ( ! same l5g? & ?is is call$ sympa!tic resonance1 or z we w\ld say 9 wireless ! =ks are 9 tune4 ,illu/ration3 ,fig4 #cf4--,s\nd ,wave & ,electric ,wave ,tun$ ,s5d]s & ,receptors4 ,a - v>iable tun+ =ks = %[+ s\nd wave tun+4 ,b - v>iable oscillation circuits = %[+ electric wave tun+4 ,tun+ =ks are made ) adju/able weights on _! prongs & by fix+ ^! to diff]5t p>ts ( !m ! frequ5cy ) :i* ! =ks vibrate c be *ang$ s9ce ! frequ5cy v>ies inv]sely ) ! squ>e ( ! l5g? & directly ) ! ?ickness ,footnote3 ,?is law is = =ks hav+ a rectangul> cross-section4 ,^? hav+ a r\nd cross-section v>y z ! radius4 ( ! prongs4 ,n[ by adju/+ "o ( ! =ks s t x vibrates at a frequ5cy (1 say1 #af p] second & adju/+ ! o!r =k s t x vibrates at a frequ5cy (1 say1 #ah or #bj p] second1 !n ! =ks w n be 9 tune ) ea* o!r &1 h5ce1 if y /rike "o ( !m ! o!r w n respond4 ,b if y make ! =ks vibrate at ! same frequ5cy1 say #af1 #bj or #bd p] second1 :5 y /rike "o ( !m ! o!r w vibrate 9 unison ) x4 ,ab\t ,electric ,tun+4--,electric resonance & electric tun+ are v l ^? ( ac\/ic resonance & ac\/ic tun+ :i* ,i h j describ$4 ,j z ac\/ic resonance may be simple or sympa!tic s electric resonance may be simple or sympa!tic4 ,simple ac\/ic resonance is ! direct re9=cem5t ( a simple vibration & ?is condition is _h :5 a tun+ =k is m\nt$ on a s\nd+ box4 ,9 simple electric resonance an oscillat+ curr5t ( a giv5 frequ5cy fl[+ 9 a circuit hav+ ! prop] inductance & capacitance may increase ! voltage until x is sev]al times great] ?an its normal value4 ,tun+ ! receptor circuits to ! transmitt] circuits are examples ( sympa!tic electric resonance4 ,z a demon/ration if y h two ,leyd5 j>s 7capacitance7 connect$ 9 circuit ) two loops ( wire 7inductance7 ^: inductance c be v>i$ z %[n at ,b 9 ,fig4 #cf1 :5 y make a sp>k pass betwe5 ! knobs ( "o ( !m by means ( a sp>k coil !n a sp>k w pass 9 ! gap ( ! o!r "o provid$ ! inductance ( ! two loops ( wire is ! same4 ,b if y v>y ! inductance ( ! "o loop s t x is l>g] or small] ?an t ( ! o!r loop no sp>k w take place 9 ! second circuit4 ,:5 a tun+ =k is made to vibrate x s5ds out waves 9 ! air1 or s\nd waves1 9 all directions & j s :5 high frequ5cy curr5ts surge 9 an oscillation circuit !y s5d out waves 9 ! e!r1 or electric waves1 t travel 9 all directions4 ,= ?is reason electric waves f a transmitt+ /ation _c be s5t to "o p>ticul> /ation1 ?\gh !y d g fur!r 9 "o direction ?an 9 ano!r1 accord+ to ! way y\r a]ial wire po9ts4 ,s9ce ! electric waves travel out 9 all directions any receiv+ set prop]ly tun$ to ! wave l5g? ( ! s5d+ /ation w receive ! waves & ! only limit on y\r ability to receive f high-p[] /ations ?r\gh\t ! _w dep5ds entirely on ! wave l5g? & s5sitivity ( y\r receiv+ set4 ,z = tun+1 j z *ang+ ! l5g? & ! ?ickness ( ! prongs ( a tun+ =k v>ies ! frequ5cy ) :i* x vibrates &1 h5ce1 ! l5g? ( ! waves x s5ds out1 s1 too1 by v>y+ ! capacitance ( ! cond5s] & ! inductance ( ! tun+ coil ( ! transmitt] ! frequ5cy ( ! electric oscillations set up 9 ! circuit may be *ang$ &1 consequ5tly1 ! l5g? ( ! electric waves !y s5d out4 ,likewise1 by v>y+ ! capacitance & ! inductance ( ! receptor ! circuits c be tun$ to receive incom+ electric waves ( :atev] l5g? )9 ! limitation ( ! app>atus4 ,,*apt] ,,viii ,a ,,simple ,,vacuum ,,tube ,,detector ,,receiv+ ,,set ,:ile y c receive dots & da%es f sp>k wireless telegraph /ations & he> spok5 words & music f wireless telephone /ations ) a cry/al detector receiv+ set su* z describ$ 9 ,*apt] ,,iii1 y c get /ations t are mu* f>!r away & he> !m bett] ) a vacuum tube detector receiv+ set4 ,?\gh ! vacuum tube detector requires two batt]ies to op]ate x & ! receiv+ circuits are some:at m complicat$ ?an :]e a cry/al detector is us$ /ill ! =m] does n h to be con/antly adju/$ z does ! latt] & ?is is ano!r v great advantage4 ,tak5 all 9 all ! vacuum tube detector is ! mo/ s5sitive & ! mo/ satisfactory ( ! detectors t are 9 use at ! pres5t "t4 ,n only is ! vacuum tube a detector ( electric wave signals & spee* & music b x c also be us$ to amplify !m1 t is1 to make !m /rong] &1 h5ce1 l\d] 9 ! telephone receiv] & fur!r its p[]s ( amplification are s great t x w reproduce !m by means ( a l\d speak]1 j z a horn amplifies ! s\nds ( a phonograph reproduc]1 until !y c be he>d by a room or an auditorium full ( p4 ,!re are two g5]al types ( l\d speak]s1 ?\gh bo? use ! pr9ciple ( ! telephone receiv]4 ,! con/ruction ( ^! l\d speak]s w be fully describ$ 9 a lat] *apt]4 ,assembl$ ,vacuum ,tube ,receiv+ ,sets4--,y c buy a receiv+ set ) a vacuum tube detector f ! v simple/ type1 :i* is describ$ 9 ?is *apt]1 to ^? t are provid$ ) reg5]ative circuits & amplify+ tubes or bo?1 :i* we %all describe 9 lat] *apt]s1 f deal]s 9 electrical app>atus g5]ally4 ,:ile "o ( ^! sets co/s m ?an y c assemble a set = y\rself1 /ill1 especially 9 ! beg9n+1 x is a good plan to buy an assembl$ "o = x is fitt$ ) a panel on :i* ! adju/+ knobs ( ! rheo/at1 tun+ coil & cond5s] are m\nt$ & ?is makes x possible to op]ate x z soon z y get x home & )\t ! slighte/ tr\ble on y\r "p4 ,y c1 h[ev]1 buy all ! v>i\s p>ts sep>ately & m\nt !m y\rself4 ,if y want ! receptor simply = receiv+ !n x is a good s*eme to h all ( ! p>ts m\nt$ 9 a box or enclos$ case1 b if y want x = exp]im5tal purposes !n ! p>ts %\ld be m\nt$ on a base or a panel s t all ( ! connections are 9 sight & accessible4 ,a ,simple ,vacuum ,tube ,receiv+ ,set4--,= ?is set y %\ld use3 7#a7 a loose c\pl$ tun+ coil1 7#b7 a v>iable cond5s]1 7#c7 a vacuum tube detector1 7#d7 an ,a or /orage batt]y giv+ #f volts1 7#e7 a ,b or dry cell batt]y giv+ #bb-a_/b volts1 7#f7 a rheo/at = v>y+ ! /orage batt]y curr5t1 & 7#g7 a pair ( #b1jjj-ohm head telephone receiv]s4 ,! loose c\pl$ tun+ coil1 ! v>iable cond5s] & ! telephone receiv]s are ! same z ^? describ$ 9 ,*apt] ,,iii4 ,! ,vacuum ,tube ,detector4 ,) ,two ,electrodes4--,a vacuum tube 9 its simple/ =m consi/s ( a glass bulb l an inc&esc5t lamp 9 :i* a wire filam5t & a metal plate are seal$ z %[n 9 ,fig4 #cg1 ,! air is !n pump$ out ( ! tube & a vacuum left or aft] x is exhau/$ x is fill$ ) nitrog51 :i* _c burn4 ,illu/ration3 ,fig4 #cg4--,two ,electrode ,vacuum ,tube ,detectors4 ,:5 ! vacuum tube is us$ z a detector1 ! wire filam5t is heat$ r$-hot & ! metal plate is *>g$ ) positive electricity ?\gh x rema9s cold4 ,! wire filam5t is =m$ into a loop l t ( an inc&esc5t lamp & its outside ends are connect$ ) a #f-volt /orage batt]y1 :i* is call$ ! ,a batt]y2 !n ! or positive t]m9al ( a #bb-a_/b volt dry cell batt]y1 call$ ! ,b batt]y1 is connect$ to ! metal plate :ile ! - or negative t]m9al ( ! batt]y is connect$ to "o ( ! t]m9als ( ! wire filam5t4 ,! diagram1 ,fig4 #cg1 simply %[s h[ ! two electrode vacuum tube1 ! ,a or dry batt]y1 & ! ,b or /orage batt]y are connect$ up4 ,?ree ,electrode ,vacuum ,tube ,detector4--,! ?ree electrode vacuum tube detector %[n at ,a 9 ,fig4 #ch1 is mu* m s5sitive ?an ! two electrode tube & has1 9 consequ5ce1 all b supplant$ x4 ,9 ?is m rec5t type ( vacuum tube ! ?ird electrode1 or grid1 z x is call$1 is plac$ betwe5 ! wire filam5t & ! metal plate & ?is all[s ! curr5t to be increas$ or decreas$ at w to a v consid]able ext5t4 ,illu/ration3 ,fig4 #ch4--,?ree ,electrode ,vacuum ,tube ,detector & ,batt]y ,connections4 ,! way ! ?ree electrode vacuum tube detector is connect$ ) ! batt]ies is %[n at ,b4 ,! plate1 ! ,a or dry cell batt]y & "o t]m9al ( ! filam5t are connect$ 9 s]ies--t is1 "o aft] ! o!r1 & ! ends ( ! filam5t are connect$ to ! ,b or /orage batt]y4 ,9 assembl+ a receiv+ set y mu/1 ( c\rse1 h a socket = ! vacuum tube4 ,a vacuum tube detector co/s f #e4jj to #f4jj4 ,! ,dry ,cell & ,/orage ,batt]ies4--,! reason t a /orage batt]y is us$ = heat+ ! filam5t ( ! vacuum tube detector is because ! curr5t deliv]$ is con/ant1 :]eas :5 a dry cell batt]y is us$ ! curr5t soon falls (f &1 h5ce1 ! heat ( ! filam5t gradually gr[s less4 ,! smalle/ ,a or #f volt /orage batt]y on ! m>ket has a capacity ( #bj to #dj amp]e h\rs1 weighs #ac p\nds & co/s ab\t #aj4jj4 ,x is %[n at ,a 9 ,fig4 #ci4 ,! ,b or dry cell batt]y = ! vacuum tube plate circuit t gives #bb-a_/b volts c be b\ght already assembl$ 9 seal$ boxes4 ,! small size is fitt$ ) a pair ( t]m9als :ile ! l>g] size is provid$ ) taps s t ! voltage requir$ by ! plate c be adju/$ z ! prop] op]ation ( ! tube requires c>eful regulation ( ! plate voltage4 ,a dry cell batt]y = a plate circuit is %[n at ,b4 ,illu/ration3 ,fig4 #ci4--;,a & ,b ,batt]ies = ,vacuum ,tube ,detectors4 ,! ,filam5t ,rheo/at4--,an adju/able resi/ance1 call$ a rheo/at1 mu/ be us$ 9 ! filam5t & /orage batt]y circuit s t ! curr5t fl[+ ?r\gh ! filam5t c be controll$ to a nicety4 ,! rheo/at consi/s ( an insulat+ & a heat resi/+ =m on :i* is w\nd a numb] ( turns ( resi/ance wire4 ,a movable contact arm t slides ov] & presses on ! turns ( wire is fix$ to ! knob on top ( ! rheo/at4 ,a rheo/at t has a resi/ance ( #f ohms & a curr5t c>ry+ capacity ( #a4e amp]es :i* c be m\nt$ on a panel bo>d is ! "r k9d to use4 ,x is %[n at ,a & ,b 9 ,fig4 #dj & co/s #a4be4 ,illu/ration3 ,fig4 #dj4--,rheo/at = ! ,a or ,/orage ,batt]y ,curr5t4 ,assembl+ ! ,p>ts4--,beg9 by plac+ all ( ! sep>ate p>ts ( ! receiv+ set on a bo>d or a base ( o!r mat]ial & set ! tun+ coil on ! left h& side ) ! adju/able swit* end t[>d ! "r h& side s t y c rea* x easily4 ,!n set ! v>iable cond5s] 9 front ( x1 set ! vacuum tube detector at ! "r h& end ( ! tun+ coil & ! rheo/at 9 front ( ! detector4 ,place ! two sets ( batt]ies back ( ! in/rum5ts & screw a c\ple ( b9d+ po/s a & b to ! "r h& l[] edge ( ! base = connect+ 9 ! head phones all ( :i* is %[n at ,a 9 ,fig4 #da4 ,illu/ration3 7,a7 ,fig4 #da4--,top ,view ( ,app>atus ,lay\t = a ,vacuum ,tube ,detector ,receiv+ ,set4 ,illu/ration3 7,b7 ,fig4 #da4--,wir+ ,diagram ( a ,simple ,vacuum ,tube ,receiv+ ,set4 ,connect+ ,up ! ,p>ts4--,to wire up ! diff]5t p>ts beg9 by connect+ ! slid+ contact ( ! prim>y coil ( ! loose c\pl$ tun+ coil 7?is y w rememb] is ! outside "o t is w\nd ) f9e wire7 to ! upp] po/ ( ! lightn+ swit* & connect "o t]m9al ( ?is coil ) ! wat] pipe4 ,n[ connect ! free end ( ! second>y coil ( ! tun+ coil 7?is is ! inside coil t is w\nd ) heavy wire7 to "o ( ! b9d+ po/s ( ! v>iable cond5s] & connect ! movable contact arm ( ! adju/able swit* ( ! prim>y ( ! tun+ coil ) ! o!r po/ ( ! v>iable cond5s]4 ,next connect ! grid ( ! vacuum tube to "o ( ! po/s ( ! cond5s] & !n connect ! plate ( ! tube to ! c>bon t]m9al ( ! ,b or dry cell batt]y :i* is ! or positive pole & connect ! z9c t]m9al ( ! - or negative pole to ! b9d+ po/ a1 connect ! po/ b to ! o!r side ( ! v>iable cond5s] & !n connect ! t]m9als ( ! head phones to ! b9d+ po/s a & b4 ,:atev] y d be c>eful n to get ! plate connections ( ! batt]y rev]s$4 ,n[ connect "o ( ! po/s ( ! rheo/at to "o t]m9al ( ! filam5t & ! o!r t]m9al ( ! filam5t to ! - or negative t]m9al ( ! ,a or /orage batt]y & ! or positive t]m9al ( ! ,a or /orage batt]y to ! o!r po/ ( ! rheo/at4 ,f9ally connect ! or positive t]m9al ( ! ,a or /orage batt]y ) ! wire t runs f ! head phones to ! v>iable cond5s]1 all ( :i* is %[n 9 ! wir+ diagram at ,b 9 ,fig4 #da4 ,adju/+ ! ,vacuum ,tube ,detector ,receiv+ ,set4--,a vacuum tube detector is tun$ exactly 9 ! same way z ! ,cry/al ,detector ,set ,no4 #b describ$ 9 ,*apt] ,,iii1 9-s-f> z ! tun+ coil & v>iable cond5s] are conc]n$4 ,! s5sitivity ( ! vacuum tube detector receiv+ set &1 h5ce1 ! di/ance ov] :i* signals & o!r s\nds c be he>d dep5ds v l>gely on ! s5sitivity ( ! vacuum tube itself & ?is 9 turn dep5ds on3 7#a7 ! "r am\nt ( heat develop$ by ! filam5t1 or filam5t brilliancy z x is call$1 7#b7 ! "r am\nt ( voltage appli$ to ! plate1 & 7#c7 ! ext5t to :i* ! tube is exhau/$ :]e ?is k9d ( a tube is us$4 ,to v>y ! curr5t fl[+ f ! ,a or /orage batt]y ?r\gh ! filam5t s t x w be heat$ to ! "r degree y adju/ ! rheo/at :ile y are li/5+ 9 to ! signals or o!r s\nds4 ,by c>efully adju/+ ! rheo/at y c easily f9d ! po9t at :i* x makes ! tube ! mo/ s5sitive4 ,a rheo/at is also useful 9 t x keeps ! filam5t f burn+ out :5 ! curr5t f ! batt]y fir/ fl[s ?r\gh x4 ,y c v (t5 increase ! s5sitiv5ess ( a vacuum tube aft] y h us$ x = a :ile by re*>g+ ! ,a or /orage batt]y4 ,! degree to :i* a vacuum tube has be5 exhau/$ has a v pron\nc$ effect on its s5sitivity4 ,! long] ! tube is us$ ! l[] its vacuum gets & g5]ally ! less s5sitive x becomes4 ,:5 ?is takes place 7& y c only guess at x7 y c v (t5 make x m s5sitive by w>m+ x ov] ! flame ( a c&le4 ,vacuum tubes hav+ a gas cont5t 79 :i* case !y are1 ( c\rse1 no long] vacuum tubes 9 ! /rict s5se7 make bett] detectors ?an tubes f :i* ! air has be5 exhau/$ & :i* are seal$ (f 9 ?is evacuat$ condition because _! s5sitiv5ess is n dep5d5t on ! degree ( vacuum z 9 ! latt] tubes4 ,moreov]1 a tube t is completely exhau/$ co/s m ?an "o t is fill$ ) gas4 ,,*apt] ,,ix ,,vacuum ,,tube ,,amplifi] ,,receiv+ ,,sets ,! reason a vacuum tube detector is m s5sitive ?an a cry/al detector is because :ile ! latt] m]ely rectifies ! oscillat+ curr5t t surges 9 ! receiv+ circuits1 ! =m] acts z an amplifi] at ! same "t4 ,! vacuum tube c be us$ z a sep>ate amplifi] 9 connection ) ei!r3 7#a7 a cry/al detector or 7#b7 a vacuum tube detector1 & 7a7 x w amplify ei!r ! radio frequ5cy curr5ts1 t is ! high frequ5cy oscillat+ curr5ts :i* are set up 9 ! oscillation circuits or 7b7 x w amplify ! audio frequ5cy curr5ts1 t is1 ! l[ frequ5cy alt]nat+ curr5ts t fl[ ?r\gh ! head phone circuit4 ,to use ! amplifi$ radio frequ5cy oscillat+ curr5ts or amplifi$ audio frequ5cy alt]nat+ curr5ts t are set up by an amplifi] tube ei!r a high resi/ance1 call$ a grid leak1 or an amplify+ trans=m]1 ) or )\t an iron core1 mu/ be connect$ ) ! plate circuit ( ! fir/ amplifi] tube & ! grid circuit ( ! next amplifi] tube or detector tube1 or ) ! wire po9t ( a cry/al detector4 ,:]e two or m amplifi] tubes are c\pl$ toge!r 9 ?is way ! s*eme is kn[n z cascade amplification4 ,:]e ei!r a radio frequ5cy trans=m]1 t is "o )\t ! iron core1 or an audio frequ5cy trans=m]1 t is "o ) ! iron core1 is us$ to c\ple ! amplifi] tube circuits toge!r bett] results are obta9$ ?an :]e a high resi/ance grid leak is us$1 b ! amplify+ tubes h to be m c>efully %ield$ f ea* o!r or !y w react & set up a h[l+ noise 9 ! head phones4 ,on ! o!r h& grid leaks co/ less b !y are m tr\blesome to use z y h to f9d out = y\rself ! exact resi/ance value !y mu/ h & ?is y c d only by te/+ !m out4 ,a ,grid ,leak ,amplifi] ,receiv+ ,set4 ,) ,cry/al ,detector4--,! app>atus y ne$ = ?is set includes3 7#a7 a loose c\pl$ tun+ coil1 7#b7 a v>iable cond5s]1 7#c7 two fix$ cond5s]s1 7#d7 a cry/al detector1 or bett] a vacuum tube detector1 7#e7 an ,a or #f volt /orage batt]y1 7#f7 a rheo/at1 7#g7 a ,b or #bb-a_/b volt dry cell batt]y1 7#h7 a fix$ resi/ance unit1 or leak grid z x is call$1 & 7#i7 a pair ( head-phones4 ,! tun+ coil1 v>iable cond5s]1 fix$ cond5s]s1 cry/al detectors & head-phones are exactly ! same z ^? describ$ 9 ,set ,no4 #b 9 ,*apt] ,,iii4 ,! ,a & ,b batt]ies are exactly ! same z ^? describ$ 9 ,*apt] ,,viii4 ,! vacuum tube amplifi] & ! grid leak are ! only new pieces ( app>atus y ne$ & n describ$ be=e4 ,! ,vacuum ,tube ,amplifi]4--,?is consi/s ( a ?ree electrode vacuum tube exactly l ! vacuum tube detector describ$ 9 ,*apt] ,,viii & pictur$ 9 ,fig4 #ch1 except t in/ead ( be+ fill$ ) a non-combu/ible gas x is evacuat$1 t is1 ! air has be5 completely pump$ out ( x4 ,! gas fill$ tube1 h[ev]1 c be us$ z an amplifi] & ei!r k9d ( tube c be us$ = ei!r radio frequ5cy or audio frequ5cy amplification1 ?\gh ) ! exhau/$ tube x is easi] to obta9 ! "r plate & filam5t voltages = good work+4 ,! ,fix$ ,resi/ance ,unit1 or ,grid ,leak4--,grid leaks are made 9 diff]5t ways b all ( !m h an enorm\sly high resi/ance4 ,"o way ( mak+ !m consi/s ( deposit+ a ?9 film ( gold on a %eet ( mica & plac+ ano!r %eet ( mica on top to protect x ! :ole be+ enclos$ 9 a glass tube z %[n at ,a 9 ,fig4 #db4 ,^! grid leaks are made 9 units ( f #ej1jjj ohms 74#je megohm7 to #e1jjj1jjj ohms 7#e megohms7 & co/ f #a to #b4 ,illu/ration3 ,fig4 #db4--;,grid ,leaks & ,h[ to ,connect ,!m up4 ,z ! value ( ! grid leak y w ne$ dep5ds v l>gely ^u ! con/ruction ( ! diff]5t p>ts ( y\r receiv+ set & on ! k9d ( a]ial wire sy/em y use ) x y w h to try out v>i\s resi/ances until y hit ! "r "o4 ,! resi/ance t w give ! be/ results1 h[ev]1 lies some:]e betwe5 #ejj1jjj ohms 7#a_/b a megohm7 & #c1jjj1jjj ohms 7#c megohms7 & ! only way = y to f9d ?is out is to buy #a_/b1 #a & #b megohm grid leak resi/ances & connect !m up 9 diff]5t ways1 z %[n at ,b1 until y f9d ! "r value4 ,assembl+ ! ,p>ts = a ,cry/al ,detector ,set4--,beg9 by lay+ ! v>i\s p>ts out on a base or a panel ) ! loose c\pl$ tun+ coil on ! left h& side1 b ) ! adju/able swit* ( ! second>y coil on ! "r h& end or 9 front accord+ to ! way x is made4 ,!n place ! v>iable cond5s]1 ! rheo/at1 ! cry/al detector & ! b9d+ po/s = ! head phones 9 front ( & 9 a l9e ) ea* o!r4 ,set ! vacuum tube amplifi] back ( ! rheo/at & ! ,a & ,b batt]ies back ( ! p>ts or 9 any o!r place t may be conv5i5t4 ,! fix$ cond5s]s & ! grid leak c be plac$ any:]e s t x w be easy to connect !m 9 & y are ready to wire up ! set4 ,connect+ ,up ! ,p>ts = a ,cry/al ,detector4--,fir/ connect ! slid+ contact ( ! prim>y ( ! tun+ coil to ! lead+-9 wire & "o ( ! end wires ( ! prim>y to ! wat] pipe1 z %[n 9 ,fig4 #dc4 ,n[ connect ! adju/able arm t makes contact ) "o end ( ! second>y ( ! tun+ coil to "o ( ! po/s ( ! v>iable cond5s]2 !n connect ! o!r po/ ( ! latt] ) a po/ ( ! fix$ cond5s] & ! o!r po/ ( ?is ) ! grid ( ! amplify+ tube4 ,illu/ration3 ,fig4 #dc4--;,cry/al ,detector ,receiv+ ,set ) ,vacuum ,tube ,amplifi] 7,resi/ance ,c\pl$74 ,connect ! fir/ po/ ( ! v>iable cond5s] to ! or positive electrode ( ! ,a batt]y & its - or negative electrode ) ! rotat+ contact arm ( ! rheo/at4 ,next connect "o end ( ! resi/ance coil ( ! rheo/at to "o ( ! po/s ( ! amplifi] tube t leads to ! filam5t & ! o!r filam5t po/ to ! or positive electrode ( ! ,a batt]y4 ,?is done connect ! negative1 t is1 ! z9c pole ( ! ,b batt]y to ! positive electrode ( ! ,a batt]y & connect ! positive1 or c>bon pole ( ! =m] ) "o end ( ! grid leak & connect ! o!r end ( ?is to ! plate ( ! amplifi] tube4 ,to ! end ( ! grid leak connect$ ) ! plate ( ! amplifi] tube connect ! metal po9t ( y\r cry/al detector1 ! cry/al ( ! latt] ) "o po/ ( ! head phones & ! o!r po/ ( !m ) ! o!r end ( ! grid leak &1 f9ally1 connect a fix$ cond5s] 9 p>allel )--t is across ! ends ( ! grid leak1 all ( :i* is %[n 9 ! wir+ diagram 9 ,fig4 #dc4 ,a ,grid ,leak ,amplify+ ,receiv+ ,set ,) ,vacuum ,tube ,detector4--,a bett] amplify+ receiv+ set c be made ?an ! "o j describ$ by us+ a vacuum tube detector in/ead ( ! cry/al detector4 ,?is set is built up exactly l ! cry/al detector describ$ above & %[n 9 ,fig4 #dc up to & includ+ ! grid leak resi/ance1 b %unt$ across ! latt] is a vacuum tube detector1 :i* is made & wir$ up precisely l ! "o %[n at ,a 9 ,fig4 #da 9 ! *apt] ahead ( ?is "o4 ,! way a grid leak & vacuum tube detector ) a "o-/ep amplifi] are connect$ up is %[n at ,a 9 ,fig4 #dd4 ,:]e y h a vacuum tube detector & "o or m amplify+ tubes connect$ up1 or 9 cascade z x is call$1 y c use an ,a1 or /orage batt]y ( #f volts = all ( !m z %[n at ,b 9 ,fig4 #dd1 b = e vacuum tube y use y mu/ h a ,b or #bb-a_/b volt dry batt]y to *>ge ! plate )4 ,illu/ration3 7,a7 ,fig4 #dd--,vacuum ,tube ,detector ,set ) ,"o ,/ep ,amplifi] 7,resi/ance ,c\pl$74 ,illu/ration3 7,b7 ,fig4 #dd4--,wir+ ,diagram = ,us+ ,"o ,a or ,/orage ,batt]y ) an ,amplifi] & a ,detector ,tube4 ,a ,radio ,frequ5cy ,trans=m] ,amplify+ ,receiv+ ,set4--,in/ead ( us+ a grid leak resi/ance to c\ple up ! amplifi] & detector tube circuits y c use a radio frequ5cy trans=m]1 t is1 a trans=m] made l a loose c\pl$ tun+ coil1 & )\t an iron core1 z %[n 9 ! wir+ diagram at ,a 9 ,fig4 #de4 ,9 ?is set1 :i* gives bett] results ?an :]e a grid leak is us$1 ! amplifi] tube is plac$ 9 ! fir/ oscillation circuit & ! detector tube 9 ! second circuit4 ,illu/ration3 7,a7 ,fig4 #de4--,wir+ ,diagram = a ,radio ,frequ5cy ,trans=m] ,amplify+ ,receiv+ ,set4 ,illu/ration3 7,b7 ,fig4 #de4--,radio ,frequ5cy ,trans=m]4 ,s9ce ! radio frequ5cy trans=m] has no iron core ! high frequ5cy1 or radio frequ5cy oscillat+ curr5ts1 z !y are call$1 surge ?r\gh x & are n *ang$ into l[ frequ5cy1 or audio frequ5cy pulsat+ curr5ts1 until !y fl[ ?r\gh ! detector4 ,s9ce ! diagram %[s only "o amplifi] & "o radio frequ5cy trans=m]1 x is consequ5tly a "o /ep amplifi]2 h[ev]1 two1 ?ree or m1 amplify+ tubes c be connect$ up by means ( an equal numb] ( radio frequ5cy trans=m]s :5 y w get wond]ful results4 ,:]e a six /ep amplifi]1 t is1 :]e six amplify+ tubes are connect$ toge!r1 or 9 cascade1 ! fir/ ?ree are usually c\pl$ up ) radio frequ5cy trans=m]s & ! la/ ?ree ) audio frequ5cy trans=m]s4 ,a radio frequ5cy trans=m] is %[n at ,b & co/s #f to #g4 ,an ,audio ,frequ5cy ,trans=m] ,amplify+ ,receiv+ ,set4--,:]e audio frequ5cy trans=m]s are us$ = /epp+ up ! voltage ( ! curr5t ( ! detector & amplifi] tubes1 ! radio frequ5cy curr5t does n get into ! plate circuit ( ! detector at all = ! reason t ! iron core ( ! trans=m] *okes !m (f1 h5ce1 ! succe$+ amplifi]s op]ate at audio frequ5cies4 ,an audio frequ5cy trans=m] is %[n at ,a 9 ,fig4 #df & a wir+ diagram %[+ h[ ! tubes are connect$ 9 cascade ) ! trans=m]s is %[n at ,b2 x is !re=e a two-/ep audio frequ5cy receiv+ set4 ,illu/ration3 7,a7 ,fig4 #df4--;,audio ,frequ5cy ,trans=m]4 ,illu/ration3 7,b7 ,fig4 #df--,wir+ ,diagram = an ,audio ,frequ5cy ,trans=m] ,amplify+ ,receiv+ ,set4 7,) ,vacuum ,tube ,detector & ,two ,/ep ,amplifi] ,tubes47 ,a ,six ,/ep ,amplifi] ,receiv+ ,set ,) a ,loop ,a]ial4--,by us+ a receiv+ set hav+ a ?ree /ep radio frequ5cy & a ?ree /ep audio frequ5cy1 t is1 a set 9 :i* !re are c\pl$ ?ree amplify+ tubes ) radio frequ5cy trans=m]s & ?ree amplify+ tubes ) audio frequ5cy trans=m]s z describ$ "u ! caption ,a ,radio ,frequ5cy ,trans=m] ,receiv+ ,set1 y c use a loop a]ial 9 y\r room ?us gett+ ar\nd ! difficulties--if su* !re be--9 erect+ an out-door a]ial4 ,y c easily make a loop a]ial by w9d+ #aj turns ( ,no4 #ad or #af copp] wire ab\t #a_/af in* ap>t on a wood5 frame two feet on ! side z %[n 9 ,fig4 #dg4 ,) ?is six /ep amplifi] set & loop a]ial y c receive wave l5g?s ( #aej to #fjj met]s f v>i\s high p[] /ations :i* are at consid]able di/ances away4 ,illu/ration3 7,a7 ,fig4 #dg4--,six ,/ep ,amplifi] ) ,loop ,a]ial4 ,illu/ration3 7,b7 ,fig4 #dg4--;,effici5t ,reg5]ative ,receiv+ ,set4 7,) ,?ree ,coil ,loose ,c\pl] ,tun]47 ,h[ to ,prev5t ,h[l+4--,:]e radio frequ5cy or audio frequ5cy amplifi]s are us$ to c\ple y\r amplifi] tubes 9 cascade y mu/ take p>ticul> pa9s to %ield !m f "o ano!r 9 ord] to prev5t ! fe$ back ( ! curr5ts ?r\gh !m1 :i* makes ! head phones or l\d speak] h[l4 ,to %ield !m f ea* o!r ! tubes %\ld be enclos$ 9 metal boxes & plac$ at lea/ #f in*es ap>t :ile ! trans=m]s %\ld be set s t _! cores are at "r angles to ea* o!r & ^! also %\ld be n less ?an six in*es ap>t4 ,,*apt] ,x ,,reg5]ative ,,amplification ,,receiv+ ,,sets ,:ile a vacuum tube detector has an amplify+ action ( its own1 & ?is acc\nts = its great s5sitiv5ess1 its amplify+ action c be fur!r increas$ to an enorm\s ext5t by mak+ ! radio frequ5cy curr5ts t are set up 9 ! oscillation circuits react on ! detector4 ,su* curr5ts are call$ fe$-back or reg5]ative curr5ts & :5 circuits are s arrang$ z to cause ! curr5ts to fl[ back ?r\gh ! detector tube ! amplification keeps on increas+ until ! capacity ( ! tube itself is rea*$4 ,x is l us+ /eam ov] & ov] aga9 9 a /eam turb9e until !re is no m en]gy left 9 x4 ,a sy/em ( circuits :i* w cause ?is reg5]ative action to take place is kn[n z ! ,arm/rong circuits & is s call$ aft] ! "y man :o discov]$ x4 ,s9ce ! reg5]ative action ( ! radio frequ5cy curr5ts is produc$ by ! detector tube itself & :i* sets up an amplify+ effect )\t ! addition ( an amplify+ tube1 ?is type ( receiv+ set has f\nd great favor ) amateurs1 :ile 9 comb9ation ) amplify+ tubes x multiplies _! p[] proportionately & x is 9 consequ5ce us$ 9 "o =m or ano!r 9 all ! bett] sets4 ,!re are _m diff]5t k9ds ( circuits :i* c be us$ to produce ! reg5]ative amplification effect :ile ! v>i\s k9ds ( tun+ coils w s]ve = c\pl+ !m2 = in/ance a two or ?ree slide s+le tun+ coil w answ] ! purpose b z x does n give good results x is n advisable to sp5d ei!r "t or money on x4 ,a bett] s*eme is to use a loose c\pl] =m$ ( two or ?ree honeycomb or o!r compact coils1 :ile a v>ioc\pl] or a v>iomet] or two w produce ! maximum reg5]ative action4 ,! ,simple/ ,type ( ,reg5]ative ,receiv+ ,set4 ,) ,loose ,c\pl$ ,tun+ ,coil4--,:ile ?is reg5]ative set is ! simple/ t w give any?+ l fair results x is "h describ$ n on acc\nt ( its desirability1 b because x w s]ve to give y ! fundam5tal idea ( h[ ! fe$-back circuit is =m$4 ,= ?is set y ne$3 7#a7 a loose-c\pl$ tun+ coil su* z describ$ 9 ,*apt] ,,iii1 7#b7 a v>iable cond5s] ( 4#jja mfd4 7micr(>ad7 capacitance2 7#c7 "o fix$ cond5s] ( 4#jja mfd42 7#d7 "o fix$ cond5s] = ! grid leak circuit ( 4#jjjbe mfd42 7#e7 a grid leak ( #a_/b to #b megohms resi/ance2 7#f7 a vacuum tube detector2 7#g7 an ,a #f volt batt]y2 7#h7 a rheo/at2 7#i7 a ,b #bb #a_/b volt batt]y2 & 7#aj7 a pair ( #bjjj ohm head phones4 ,connect+ ,up ! ,p>ts4--,beg9 by connect+ ! lead+-9 wire ( ! a]ial ) ! b9d+ po/ end ( ! prim>y coil ( ! loose c\pl] z %[n 9 ! wir+ diagram ,fig4 #dh & !n connect ! slid+ contact ) ! wat] pipe or o!r gr\nd4 ,connect ! b9d+ po/ end ( ! prim>y coil ) "o po/ ( ! v>iable cond5s]1 connect ! o!r po/ ( ?is ) "o ( ! po/s ( ! 4#jjjbe mfd4 cond5s] & ! o!r end ( ?is ) ! grid ( ! detector tube2 !n ar\nd ?is cond5s] %unt ! grid leak resi/ance4 ,illu/ration3 ,fig4 #dh4--,simple ,reg5]ative ,receiv+ ,set4 7,) ,loose ,c\pl] ,tun]47 ,next connect ! slid+ contact ( ! prim>y coil ) ! o!r po/ ( ! v>iable cond5s] & f ?is lead a wire on ov] to "o ( ! t]m9als ( ! filam5t ( ! vacuum tube2 to ! o!r t]m9al ( ! filam5t connect "o ( ! po/s ( ! rheo/at & connect ! o!r po/ to ! - or negative electrode ( ! ,a batt]y & !n connect ! or positive electrode ( x to ! o!r t]m9al ( ! filam5t4 ,connect ! or positive electrode ( ! ,a batt]y ) "o po/ ( ! 4#jja mfd4 fix$ cond5s] & connect ! o!r po/ ( ?is to "o ( ! ends ( ! second>y coil ( ! tun+ coil & :i* is n[ kn[n z ! tickl] coil2 !n connect ! o!r end ( ! second>y1 or tickl] coil to ! plate ( ! vacuum tube4 ,9 ! wir+ diagram ! second>y1 or tickl] coil is %[n above & 9 a l9e ) ! prim>y coil b ?is is only = ! sake ( mak+ ! connections cle>2 9 reality ! second>y1 or tickl] coil slides to & fro 9 ! prim>y coil z %[n & describ$ 9 ,*apt] ,,iii4 ,f9ally connect ! negative1 or z9c pole ( ! ,b batt]y to "o side ( ! fix$ cond5s]1 ! positive1 or c>bon1 pole to "o ( ! t]m9als ( ! head phones & ! o!r t]m9al ( ?is to ! o!r po/ ( ! fix$ cond5s] :5 y\r reg5]ative set is complete4 ,an ,effici5t ,reg5]ative ,receiv+ ,set4 ,) ,?ree ,coil ,loose ,c\pl]4--,to con/ruct a really good reg5]ative set y mu/ use a loose c\pl$ tun] t has ?ree coils1 namely a prim>y1 a second>y & a tickl] coil4 ,a tun] ( ?is k9d is made l an ord9>y loose c\pl$ tun+ coil b x has a ?ird coil z %[n at ,a & ,b 9 ,fig4 #di4 ,! middle coil1 :i* is ! second>y1 is fix$ to ! base1 & ! l>ge outside coil1 :i* is ! prim>y1 is movable1 t is x slides to & fro ov] ! middle coil1 :ile ! small inside coil1 :i* is ! tickl]1 is also movable & c slide 9 or out ( ! middle coil4 ,none ( ^! coils is v>iable2 all are w\nd to receive waves up to #cfj met]s 9 l5g? :5 us$ ) a v>iable cond5s] ( 4#jja mfd4 capacitance4 ,9 o!r words y slide ! coils 9 & out to get ! "r am\nt ( c\pl+ & y tune by adju/+ ! v>iable cond5s] to get ! exact wave l5g? y want4 ,illu/ration3 7,a7 ,fig4 #di4--;,diagram ( a ,?ree ,coil ,c\pl]4 ,illu/ration3 7,b7 ,fig4 #di4--,?ree ,coil ,loose ,c\pl] ,tun]4 ,) ,compact ,coils4--,compact coil tun]s are =m$ ( ?ree fix$ inductances w\nd 9 flat coils1 & ^! are pivot$ 9 a m\nt+ s t ! di/ance betwe5 !m &1 !re=e1 ! c\pl+1 c be v>i$1 z %[n at ,a 9 ,fig4 #ej4 ,^! coils are w\nd up by ! mak]s = v>i\s wave l5g?s rang+ f a small "o t w receive waves ( any l5g? up to #cfj met]s to a l>ge "o t has a maximum ( #bd1jjj met]s4 ,= an amateur set get ?ree ( ! smalle/ coils :5 y c n only he> amateur /ations t s5d on a #bjj met] wave b broadca/+ /ations t s5d on a #cfj met] wave4 ,illu/ration3 ,fig4 #ej4--;,honeycomb ,inductance ,coil4 ,^! ?ree coils are m\nt$ ) panel plugs :i* latt] fit into a /&1 or m\nt+1 s t ! middle coil is fix$1 t is1 /ation>y1 :ile ! two outside coils c be swung to & fro l a door2 ?is s*eme p]mits small v>iations ( c\pl+ to be _h betwe5 ! coils & ?is c be done ei!r by h&les or by means ( knobs on a panel bo>d4 ,:ile ,i h sugge/$ ! use ( ! smalle/ size coils1 y c get & use ^? w\nd = any wave l5g? y want to receive & :5 ^? are connect$ ) v>iomet]s & v>iable cond5s]s1 & ) a prop] a]ial1 y w h a highly effici5t receptor t w "w ov] all ranges ( wave l5g?s4 ,! smalle/ size coils co/ ab\t #a4ej apiece & ! m\nt+ co/s ab\t #f or #g ea*4 ,! ,a ,batt]y ,pot5tiomet]4--,?is device is simply a resi/ance l ! rheo/at describ$ 9 connection ) ! prec$+ vacuum tube receiv+ sets b x is w\nd to #bjj or #cjj ohms resi/ance z aga9/ #a-a_/b to #f ohms ( ! rheo/at4 ,x is1 h[ev]1 us$ z well z ! rheo/at4 ,) a vacuum tube detector1 & especially ) "o hav+ a gas-cont5t1 a pot5tiomet] is v necess>y z x is only by means ( x t ! pot5tial ( ! plate ( ! detector c be accurately regulat$4 ,! result ( prop] regulation is t :5 ! critical pot5tial value is rea*$ !re is a m>k$ increase 9 ! l\dness ( ! s\nds t are emitt$ by ! head phones4 ,z y w see f ,a 9 ,fig4 #ea x has ?ree taps4 ,! two taps :i* are connect$ ) ! ends ( ! resi/ance coil are %unt$ ar\nd ! ,a batt]y & ! ?ird tap1 :i* is atta*$ to ! movable contact arm1 is connect$ ) ! ,b batt]y tap1 see ,b1 at :i* ?is batt]y gives #ah volts4 ,s9ce ! ,a batt]y gives #f volts y c v>y ! pot5tial ( ! plate f #ah to #bd volts4 ,! pot5tiomet] mu/ nev] be %unt$ ar\nd ! ,b batt]y or ! latt] w soon run d[n4 ,a pot5tiomet] co/s a c\ple ( doll>s4 ,illu/ration3 7,a7 ,fig4 #ea4--,! ,use ( ! ,pot5tiomet]4 ,! ,p>ts & ,h[ to ,connect ,!m ,up4--,= ?is reg5]ative set y w ne$3 7#a7 a honeycomb or o!r compact ?ree-coil tun]1 7#b7 two v>iable 74#jja & 4#jjje mfd47 cond5s]s2 7#c7 a 4#jjjbe mfd4 fix$ cond5s]2 7#d7 a #a_/b to #b megohm grid leak2 7#e7 a tube detector2 7#f7 a #f volt ,a batt]y2 7#g7 a rheo/at2 7#h7 a pot5tiomet]2 7#i7 an #ah or #bj volt ,b batt]y2 7#aj7 a fix$ cond5s] ( 4#jja mfd4 fix$ cond5s]2 & 7#aa7 a pair ( #bjjj ohm head phones4 ,to wire up ! p>ts connect ! lead+-9 wire ( ! a]ial ) ! prim>y coil1 :i* is ! middle "o ( ! tun]1 & connect ! o!r t]m9al ) ! gr\nd4 ,connect ! ends ( ! second>y coil1 :i* is ! middle "o1 ) ! po/s ( ! v>iable cond5s] & connect "o ( ! po/s ( ! latt] ) "o po/ ( ! fix$ 4#jjjbe mfd4 cond5s] & ! o!r po/ ( ?is ) ! grid2 !n %unt ! grid leak ar\nd x4 ,next connect ! o!r po/ ( ! v>iable cond5s] to ! - or negative electrode ( ! ,a batt]y2 ! or positive electrode ( ?is to "o t]m9al ( ! detector filam5t & ! o!r end ( ! latt] to ! electrode ( ! ,a batt]y4 ,n[ connect "o end ( ! tickl] coil ) ! detector plate & ! o!r po/ to ! fix$ 4#jja mfd4 cond5s]1 !n ! o!r end ( ?is to ! positive or c>bon pole ( ! ,b batt]y4 ,?is done %unt ! pot5tiomet] ar\nd ! ,a batt]y & run a wire f ! movable contact ( x 7! pot5tiomet]7 ov] to ! #ah volt tap1 7see ,b1 ,fig4 #ea71 ( ! ,b batt]y4 ,f9ally1 %unt ! head phones & ! 4#jja mfd4 fix$ cond5s] & y are ready to try out conclusions4 ,a ,reg5]ative ,audio ,frequ5cy ,amplifi] ,receiv+ ,set4--,! use ( amateur reg5]ative cascade audio frequ5cy receiv+ sets is gett+ to be q common4 ,to get ! greate/ amplification possible ) amplify+ tubes y h to keep a negative pot5tial on ! grids4 ,y c1 h[ev]1 get v good results )\t any special *>g+ arrangem5t by simply connect+ "o po/ ( ! rheo/at ) ! negative t]m9al ( ! filam5t & connect+ ! l[ pot5tial end ( ! second>y ( ! tun+ coil ) ! - or negative electrode ( ! ,a batt]y4 ,?is s*eme w give ! grids a negative bias ( ab\t #a volt4 ,y d n ne$ to bo!r ab\t ^! add$ factors t make = high effici5cy until aft] y h got y\r receiv+ set 9 work+ ord] & und]/& all ab\t x4 ,! ,p>ts & ,h[ to ,connect ,!m ,up4--,exactly ! same p>ts are ne$$ = ?is set z ! "o describ$ above1 b 9 addition y w want3 7#a7 two m rheo/ats2 7#b7 two m sets ( ,b #bb-a_/b volt batt]ies2 7#c7 two amplifi] tubes1 & 7#d7 two audio frequ5cy trans=m]s z describ$ 9 ,*apt] ,,ix & pictur$ at ,a 9 ,fig4 #df4 ,to wire up ! p>ts beg9 by connect+ ! lead+-9 wire to "o end ( ! prim>y ( ! tun+ coil & !n connect ! o!r end ( ! coil ) ! gr\nd4 ,a v>iable cond5s] ( 4#jja mfd4 capacitance c be connect$ 9 ! gr\nd wire1 z %[n 9 ,fig4 #eb1 to good advantage al?\gh x is n absolutely ne$$4 ,n[ connect "o end ( ! second>y coil to "o po/ ( a 4#jja mfd4 v>iable cond5s] & ! o!r end ( ! second>y to ! o!r po/ ( ! cond5s]4 ,illu/ration3 ,fig4 #eb4--,reg5]ative ,audio ,frequ5cy ,amplifi] ,receiv+ ,set4 ,next br+ a lead 7wire7 f ! fir/ po/ ( ! v>iable cond5s] ov] to ! po/ ( ! fir/ fix$ cond5s] & connect ! o!r po/ ( ! latt] ) ! grid ( ! detector tube4 ,%unt #a_/b to #b megohm grid leak resi/ance ar\nd ! fix$ cond5s] & !n connect ! second po/ ( ! v>iable cond5s] to "o t]m9al ( ! detector tube filam5t4 ,run ?is wire on ov] & connect x ) ! fir/ po/ ( ! second rheo/at1 ! second po/ ( :i* is connect$ ) "o t]m9al ( ! filam5t ( ! fir/ amplify+ tube2 !n connect ! fir/ po/ ( ! rheo/at ) "o end ( ! second>y coil ( ! fir/ audio frequ5cy trans=m]1 & ! o!r end ( ?is coil ) ! grid ( ! fir/ amplifi] tube4 ,connect ! lead t runs f ! second po/ ( v>iable cond5s] to ! fir/ po/ ( ! ?ird rheo/at1 ! second po/ ( :i* is connect$ ) "o t]m9al ( ! second amplify+ tube2 !n connect ! fir/ po/ ( ! rheo/at ) "o end ( ! second>y coil ( ! second audio frequ5cy trans=m] & ! o!r end ( ?is coil ) ! grid ( ! second amplifi] tube4 ,?is done connect ! - or negative electrode ( ! ,a batt]y ) ! second po/ ( ! v>iable cond5s] & connect ! or positive electrode ) ! free po/ ( ! fir/ rheo/at1 ! o!r po/ ( :i* connects ) ! free t]m9al ( ! filam5t ( ! detector4 ,f ?is lead tap (f a wire & connect x to ! free t]m9al ( ! filam5t ( ! fir/ amplifi] tube1 & f9ally connect ! end ( ! lead ) ! free t]m9al ( ! filam5t ( ! second amplifi] tube4 ,next %unt a pot5tiomet] ar\nd ! ,a batt]y & connect ! ?ird po/1 :i* connects ) ! slid+ contact1 to ! negative or z9c pole ( a ,b batt]y1 !n connect ! positive or c>bon pole ( x to ! negative or z9c pole ( a second ,b batt]y & ! positive or c>bon pole ( ! latt] ) "o end ( ! prim>y coil ( ! second audio frequ5cy trans=m] & ! o!r end ( x to ! plate ( ! fir/ amplify+ tube4 ,run ! lead on ov] & connect x to "o ( ! t]m9als ( ! second fix$ cond5s] & ! o!r t]m9al ( ?is ) ! plate ( ! second amplify+ tube4 ,!n %unt ! headphones ar\nd ! cond5s]4 ,f9ally connect "o end ( ! tickl] coil ( ! tun] ) ! plate ( ! detector tube & connect ! o!r end ( ! tickl] to "o end ( ! prim>y coil ( ! fir/ audio frequ5cy trans=m] & ! o!r end ( x to ! wire t connects ! two ,b batt]ies toge!r4 ,,*apt] ,,xi ,,%ort ,,wave ,,reg5]ative ,,receiv+ ,,sets ,a %ort wave receiv+ set is "o t w receive a range ( wave l5g?s ( f #aej to #fjj met]s :ile ! di/ance ov] :i* ! waves c be receiv$ z well z ! int5sity ( ! s\nds reproduc$ by ! headphones dep5ds on3 7#a7 :e!r x is a reg5]ative set & 7#b7 :e!r x is provid$ ) amplify+ tubes4 ,high-grade reg5]ative sets design$ especially = receiv+ amateur s5d+ /ations t mu/ use a %ort wave l5g? are built on ! reg5]ative pr9ciple j l ^? describ$ 9 ! la/ *apt] & fur!r amplification c be _h by ! use ( amplifi] tubes z expla9$ 9 ,*apt] ,,ix1 b ! new feature ( ^! sets is ! use ( ! v>ioc\pl] & "o or m v>iomet]s4 ,^! tun+ devices c be connect$ up 9 diff]5t ways & are v popul> ) amateurs at ! pres5t "t4 ,diff]+ f ! ord9>y loose c\pl] ! v>iomet] has no movable contacts :ile ! v>iomet] is provid$ ) taps s t y c connect x up = ! wave l5g? y want to receive4 ,all y h to d is to tune ! oscillation circuits to ea* o!r is to turn ! rotor1 :i* is ! second>y coil1 ar\nd 9 ! /ator1 z ! prim>y coil is call$ 9 ord] to get a v f9e v>iation ( ! wave l5g?4 ,x is ?is con/ruction t makes %>p tun+ ) ^! sets possible1 by :i* is meant t all wave l5g?s are tun$ out except ! "o :i* ! receiv+ set is tun$ =4 ,a ,%ort ,wave ,reg5]ative ,receiv]--,) ,"o ,v>iomet] & ,?ree ,v>iable ,cond5s]s4--,?is set also includes a v>ioc\pl] & a grid coil4 ,! way t ! p>ts are connect$ toge!r makes x a simple & at ! same "t a v effici5t reg5]ative receiv] = %ort waves4 ,:ile ?is set c be us$ )\t %ield+ ! p>ts f ea* o!r ! be/ results are _h :5 %ields are us$4 ,! p>ts y ne$ = ?is set include3 7#a7 "o v>ioc\pl]2 7#b7 "o 4#jja micr(>ad v>iable cond5s]2 7#c7 "o 4#jjje micr(>ad v>iable cond5s]2 7#d7 "o 4#jjjg micr(>ad v>iable cond5s]2 7#e7 "o #b megohm grid leak2 7#f7 "o vacuum tube detector2 7#g7 "o #f volt ,a batt]y2 7#h7 "o #f ohm1 #a-a_/b amp]e rheo/at2 7#i7 "o #bjj ohm pot5tiomet]2 7#aj7 "o #bb-a_/b volt ,b batt]y2 7#aa7 "o 4#jja micr(>ad fix$ cond5s]1 7#ab7 "o pair ( #b1jjj ohm headphones1 & 7#ac7 a v>iomet]4 ,! ,v>ioc\pl]4--,a v>ioc\pl] consi/s ( a prim>y coil w\nd on ! outside ( a tube ( insulat+ mat]ial & to c]ta9 turns ( ?is taps are connect$ s t y c fix ! wave l5g? :i* y\r a]ial sy/em is to receive f ! %orte/ wave2 i4e41 #aej met]s on up by /eps to ! longe/ wave1 i4e41 #fjj met]s1 :i* is ! range ( mo/ amateur v>ioc\pl]s t are sold 9 ! op5 m>ket4 ,?is is ! "p ( ! v>ioc\pl] t is call$ ! /ator4 ,! second>y coil is w\nd on ! section ( a ball m\nt$ on a %aft & ?is is swung 9 be>+s on ! /ator s t x c turn 9 x4 ,?is "p ( ! v>ioc\pl] is call$ ! rotor & is arrang$ s t x c be m\nt$ on a panel & adju/$ by means ( a knob or a dial4 ,a diagram ( a v>ioc\pl] is %[n at ,a 9 ,fig4 #ec1 & ! c\pl] itself at ,b4 ,!re are v>i\s makes & modifications ( v>ioc\pl]s on ! m>ket b all ( !m are ab\t ! same price :i* is #f4jj or #h4jj4 ,illu/ration3 ,fig4 #ec4--;,h[ ! ,v>ioc\pl] is ,made & ,works4 ,! ,v>iomet]4--,?is device is q l ! v>ioc\pl]1 b ) ^! diff]5ces3 7#a7 ! rotor turns 9 ! /ator1 :i* is also ! section ( a ball1 & 7#b7 "o end ( ! prim>y is connect$ ) "o end ( ! second>y coil4 ,to be really effici5t a v>iomet] mu/ h a small resi/ance & a l>ge inductance z well z a small dielectric loss4 ,to secure ! fir/ two ( ^! factors ! wire %\ld be =m$ ( a numb] ( f9e1 pure copp] wires ea* ( :i* is insulat$ & ! :ole /r& !n cov]$ ) silk4 ,?is k9d ( wire is ! be/ t has yet be5 devis$ = ! purpose & is sold "u ! trade "n ( litz5draht4 ,a new type ( v>iomet] has :at is kn[n z a basket weave1 or wavy w\nd /ator & rotor4 ,!re is no wood1 insulat+ comp\nd or o!r dielectric mat]ials 9 l>ge en\gh quantities to absorb ! weak curr5ts t fl[ betwe5 !m1 h5ce weak] s\nds c be he>d :5 ?is k9d ( a v>iomet] is us$4 ,) x y c tune %>ply to waves "u #bjj met]s 9 l5g? & up to & includ+ wave l5g?s ( #cfj met]s4 ,:5 amateur /ations ( small p[] are s5d+ on ^! %ort waves ?is /yle ( v>iomet] keeps ! electric oscillations at _! greate/ /r5g? &1 h5ce1 ! reproduc$ s\nds w be ( maximum int5sity4 ,a wir+ diagram ( a v>iomet] is %[n at ,a 9 ,fig4 #ed & a basketball v>iomet] is %[n complete at ,b4 ,illu/ration3 ,fig4 #ed4--;,h[ ! ,v>iomet] is ,made & ,works4 ,connect+ ,up ! ,p>ts4--,to hook-up ! set connect ! lead+-9 wire to "o end ( ! prim>y coil1 or /ator1 ( ! v>ioc\pl] & sold] a wire to "o ( ! taps t gives ! longe/ wave l5g? y want to receive4 ,connect ! o!r end ( ?is wire ) "o po/ ( a 4#jja micr(>ad v>iable cond5s] & connect ! o!r po/ ) ! gr\nd z %[n 9 ,fig4 #ee4 ,n[ connect "o end ( ! second>y coil1 or rotor1 to "o po/ ( a 4#jjjg mfd4 v>iable cond5s]1 ! o!r po/ ( ?is to "o end ( ! grid coil & ! o!r end ( ?is ) ! rema9+ end ( ! rotor ( ! v>ioc\pl]4 ,illu/ration3 ,fig4 #ee4--,%ort ,wave ,reg5]ative ,receiv+ ,set 7"o ,v>iomet] & ?ree ,v>iable ,cond5s]s47 ,next connect "o po/ ( ! 4#jjjg mfd4 cond5s] ) "o ( ! t]m9als ( ! detector filam5t2 !n connect ! o!r po/ ( ?is cond5s] ) "o po/ ( ! 4#jjje mfd4 v>iable cond5s] & ! o!r po/ ( ?is ) ! grid ( ! detector1 !n %unt ! megohm grid leak ar\nd ! latt] cond5s]4 ,?is done connect ! o!r t]m9al ( ! filam5t to "o po/ ( ! rheo/at1 ! o!r po/ ( ?is to ! - or negative electrode ( ! #f volt ,a batt]y & ! or positive electrode ( ! latt] to ! o!r t]m9al ( ! filam5t4 ,%unt ! pot5tiomet] ar\nd ! ,a batt]y & connect ! slid+ contact ) ! - or z9c pole ( ! ,b batt]y & ! or c>bon pole ) "o t]m9al ( ! headphone2 connect ! o!r t]m9al to "o ( ! po/s ( ! v>iomet] & ! o!r po/ ( ! v>iomet] to ! plate ( ! detector4 ,f9ally %unt a 4#jja mfd4 fix$ cond5s] ar\nd ! headphones4 ,if y want to amplify ! curr5t ) a vacuum tube amplifi] connect 9 ! t]m9als ( ! amplifi] circuit %[n at ,a 9 ,figs4 #dd or #de at ! po9t :]e !y are connect$ ) ! second>y coil ( ! loose c\pl$ tun+ coil1 9 ^? diagrams ) ! b9d+ po/s ( ,fig4 #ee :]e ! phones are usually connect$ 94 ,%ort ,wave ,reg5]ative ,receiv]4 ,) ,two ,v>iomet]s & ,two ,v>iable ,cond5s]s4--,?is type ( reg5]ative receptor is v popul> ) amateurs :o are us+ high-grade %ort-wave sets4 ,:5 y connect up ?is receptor y mu/ keep ! v>i\s p>ts well sep>at$4 ,screw ! v>ioc\pl] to ! middle ( ! base bo>d or panel1 & secure ! v>iomet]s on ei!r side ( x s t ! di/ance betwe5 !m w be #i or #aj in*es4 ,by s plac+ !m ! c\pl+ w be ! same on bo? sides & besides y c %ield !m f ea* o!r easi]4 ,= ! %ield use a %eet ( copp] on ! back ( ! panel & place a %eet ( copp] betwe5 ! p>ts1 or bett]1 enclose ! v>iomet]s & detector & amplify+ tubes if y use ! latt] 9 %eet copp] boxes4 ,:5 y set up ! v>iomet]s place !m s t _! /ators are at "r angles to ea* o!r = o!rwise ! magnetic l9es ( =ce set up by ! coils ( ea* "o w be mutually inductive & ?is w make ! headphones or l\d speak] h[l4 ,:atev] t5d5cy ! receptor has to h[l ) ?is arrangem5t c be ov]come by putt+ 9 a grid leak ( ! "r resi/ance & adju/+ ! cond5s]4 ,! ,p>ts & ,h[ to ,connect ,!m ,up4--,= ?is set y require3 7#a7 "o v>ioc\pl]2 7#b7 two v>iomet]s2 7#c7 "o 4#jja micr(>ad v>iable cond5s]2 7#d7 "o 4#jjje micr(>ad v>iable cond5s]2 7#e7 "o #b megohm grid leak resi/ance2 7#f7 "o vacuum tube detector2 7#g7 "o #f volt ,a batt]y2 7#h7 "o #bjj ohm pot5tiomet]2 7#i7 "o #bb-a_/b volt ,b batt]y2 7#aj7 "o 4#jja micr(>ad fix$ cond5s]1 & 7#aa7 "o pair ( #b1jjj ohm headphones4 ,to wire up ! set beg9 by connect+ ! lead+-9 wire to ! fix$ end ( ! prim>y coil1 or /ator1 ( ! v>ioc\pl]1 z %[n 9 ,fig4 #ef1 & connect "o po/ ( ! 4#jja mfd4 v>iable cond5s] to ! /ator by sold]+ a %ort l5g? ( wire to ! tap ( ! latt] t gives ! longe/ wave y want to receive4 ,n[ connect "o end ( ! second>y coil1 or rotor1 ( ! v>ioc\pl] ) "o po/ ( ! 4#jjje mfd4 v>iable cond5s] & ! o!r "p to ! grid ( ! detector tube4 ,connect ! o!r end ( ! rotor ( ! v>ioc\pl] to "o ( ! po/s ( ! fir/ v>iomet] & ! o!r po/ ( ?is to "o ( ! t]m9als ( ! detector filam5t4 ,illu/ration3 ,fig4 #ef4--,%ort ,wave ,reg5]ative ,receiv+ ,set 7two ,v>iomet]s & two ,v>iable ,cond5s]s47 ,connect ?is filam5t t]m9al ) ! - or negative electrode ( ! ,a batt]y & ! or positive electrode ( ?is ) "o po/ ( ! rheo/at & lead a wire f ! o!r po/ to ! free t]m9al ( ! filam5t4 ,?is done %unt ! pot5tial ar\nd ! ,a batt]y & connect ! slid+ contact to ! - or z9c pole ( ! ,b batt]y & ! or c>bon pole ( ?is to "o t]m9al ( ! headphones1 :ile ! o!r t]m9al ( ?is leads to "o ( ! po/s ( ! second v>iomet]1 ! o!r po/ ( :i* is connect$ to ! plate ( ! detector tube4 ,if y want to add an amplifi] tube !n connect x to ! po/s in/ead ( ! headphones z describ$ 9 ! =ego+ set4 ,,*apt] ,,xii ,,int]m$iate ,,& ,,long ,,wave ,,reg5]ative ,,receiv+ ,,sets ,all receiv+ sets t receive ov] a range ( wave l5g?s ( f #aej met]s to #c1jjj met]s are call$ int]m$iate wave sets & all sets t receive wave l5g?s ov] a range ( any?+ m ?an #c1jjj met]s are call$ long wave sets4 ,! range ( int]m$iate wave receptors is su* t !y w receive amateur1 broadca/+1 %ip & %ore ,navy1 comm]cial1 ,arl+ton's "t & all o!r /ations us+ sp>k telegraph damp$ waves or arc or vacuum tube telephone cont9u\s waves b n cont9u\s wave telegraph signals1 unless ^! h be5 brok5 up into gr\ps at ! transmitt+ /ation4 ,to receive cont9u\s wave telegraph signals requires receiv+ sets ( special k9d & ^! w be describ$ 9 ! next *apt]4 ,int]m$iate ,wave ,receiv+ ,sets4--,!re are two *ief s*emes employ$ to increase ! range ( wave l5g?s t a set c receive & ^! are by us+3 7#a7 load+ coils & %unt cond5s]s1 & 7#b7 bank-w\nd coils & v>iable cond5s]s4 ,if y h a %ort-wave set & plan to receive int]m$iate waves ) x !n load+ coils & fix$ cond5s]s %unt$ ar\nd !m af=ds y ! way to d x1 b if y pref] to buy a new receptor !n ! bett] way is to get "o ) bank-w\nd coils & v>iable cond5s]s2 ?is latt] way pres]ves ! electrical balance ( ! oscillation circuits bett]1 ! electrical losses are less & ! tun+ easi] & %>p]4 ,int]m$iate ,wave ,set ,) ,load+ ,coils4--,= ?is int]m$iate wave set y c use ei!r ( ! %ort-wave sets describ$ 9 ! =ego+ *apt]4 ,= ! load+ coils use honeycomb coils1 or o!r good compact inductance coils1 z %[n 9 ,*apt] ,x & hav+ a range ( :atev] wave l5g? y wi% to receive4 ,! foll[+ table %[s ! range ( wave l5g? ( ! v>i\s siz$ coils :5 us$ ) a v>iable cond5s] hav+ a 4#jja micr(>ad capacitance1 ! approximate inductance ( ea* coil 9 millih5ries & prices at ! pres5t writ+3 ,,table ,,( ,,*>act]i/ics ,,( ,,honeycomb ,,coils ,approximate ,wave ,l5g? 9 ,met]s 9 ,millih5ries ,inductance 4#jja mfd4 ,v>iable ,m\nt$ ,appx4 ,air ,cond5s]4 on ,plug 4#jdj #acj-- #cge #a4dj 4#jge #ahj-- #eae #a4dj 4#ae #bdj-- #gcj #a4ej 4#c #ccj-- #ajcj #a4ej 4#f #dej-- #adfj #a4ee #a4c #ffj-- #bbjj #a4fj #b4c #icj-- #bhej #a4fe #d4e #acjj-- #djjj #a4gj #f4e #aeej-- #dhjj #a4ge #aa4 #bjej-- #fcjj #a4hj #bj4 #cjjj-- #hejj #b4jj #dj4 #djjj--abjjj #b4ae #fe4 #ejjj--aejjj #b4ce #ajj4 #fbjj--aijjj #b4fj #abe4 #gjjj--bajjj #c4jj #age4 #hbjj--bdjjj #c4ej ,^! & o!r k9ds ( compact coils c be b\ght at electrical supply h\ses t sell wireless goods4 ,if y\r a]ial is n v high or long y c use load+ coils1 b to get any?+ l effici5t results ) !m y mu/ h an a]ial ( l>ge capacitance & ! only way to get ?is is to put up a high & long "o ) two or m p>allel wires spac$ a goodly di/ance ap>t4 ,! ,p>ts & ,h[ to ,connect ,!m ,up4--,get 7#a7 two honeycomb or o!r coils ( ! greate/ wave l5g? y want to receive1 = 9 ord] to prop]ly balance ! a]ial1 or prim>y oscillation circuit1 & ! clos$1 or second>y oscillation circuit1 y h to tune !m to ! same wave l5g?2 7#b7 two 4#jja mfd4 v>iable cond5s]s1 ?\gh fix$ cond5s]s w d1 & 7#c7 two small s+le-?r[ d\ble-pole knife swit*es m\nt$ on porcela9 bases4 ,to use ! load+ coils all y h to d is to connect "o ( !m 9 ! a]ial above ! prim>y coil ( ! loose c\pl]1 or v>ioc\pl] z %[n 9 ! wir+ diagram 9 ,fig4 #eg1 !n %unt "o ( ! cond5s]s ar\nd x & connect "o ( ! swit*es ar\nd ?is2 ?is swit* enables y to cut 9 or out ! load+ coil at w4 ,likewise connect ! o!r load+ coil 9 "o side ( ! clos$1 or second>y circuit betwe5 ! v>iable 4#jjjg mfd4 cond5s] & ! second>y coil ( ! loose c\pl] or v>ioc\pl] z %[n 9 ,fig4 #ec4 ,! o!r connections are exactly ! same z %[n 9 ,figs4 #dd & #de4 ,illu/ration3 ,fig4 #eg4--,wir+ ,diagram ,%[+ ,fix$ ,load+ ,coils = ,int]m$iate ,wave ,set4 ,an ,int]m$iate ,wave ,set ,) ,v>ioc\pl] ,inductance ,coils4--,by us+ ! coil w\nd on ! rotor ( ! v>ioc\pl] z ! tickl] ! c\pl+ betwe5 ! detector tube circuits & ! a]ial wire sy/em increases z ! set is tun$ = great] wave l5g?s4 ,?is s*eme makes ! control ( ! reg5]ative circuit f> m /able ?an x is :]e an ord9>y loose c\pl$ tun+ coil is us$4 ,:5 ! v>ioc\pl] is adju/$ = receiv+ v long waves ! rotor sets at "r angles to ! /ator &1 s9ce :5 x is 9 ?is position !re is no mutual induction betwe5 !m1 ! tickl] coil s]ves z a load+ coil = ! detector plate oscillation circuit4 ,inductance coils = %ort wave l5g?s are usually w\nd 9 s+le lay]s b bank-w\nd coils1 z !y are call$ are necess>y to get compactness :]e long wave l5g?s are to be receiv$4 ,by w9d+ inductance coils ) two or m lay]s ! highe/ inductance values c be obta9$ ) ! lea/ resi/ance4 ,a wir+ diagram ( a multipo9t inductance coil is %[n 9 ,fig4 #eh4 ,y c buy ?is int]m$iate wave set assembl$ & ready to use or get ! p>ts & connect !m up y\rself4 ,illu/ration3 ,fig4 #eh4--,wir+ ,diagram = ,int]m$iate ,wave ,receptor ) "o ,v>ioc\pl] & #ab section ,bank-w\nd ,inductance ,coil4 ,! ,p>ts & ,h[ to ,connect ,!m ,up4--,= ?is reg5]ative int]m$iate wave set get3 7#a7 "o #ab section triple bank-w\nd inductance coil1 7#b7 "o v>iomet]1 & 7#c7 all ! o!r p>ts %[n 9 ! diagram ,fig4 #eh except ! v>ioc\pl]4 ,fir/ connect ! free end ( ! cond5s] 9 ! a]ial to "o ( ! t]m9als ( ! /ator ( ! v>ioc\pl]2 !n connect ! o!r t]m9al ( ! /ator ) "o ( ! ends ( ! bank-w\nd inductance coil & connect ! movable contact ( ?is ) ! gr\nd4 ,next connect a wire to ! a]ial betwe5 ! v>iable cond5s] & ! /ator & connect ?is to "o po/ ( a 4#jjje micr(>ad fix$ cond5s]1 !n connect ! o!r po/ ( ?is ) ! grid ( ! detector & %unt a #b megohm grid leak ar\nd x4 ,connect a wire to ! gr\nd wire betwe5 ! bank-w\nd inductance coil & ! gr\nd prop]1 i4e41 ! radiator or wat] pipe1 connect ! o!r end ( ?is to ! electrode ( ! ,a batt]y & connect ?is end also to "o ( ! t]m9als ( ! filam5t4 ,?is done connect ! o!r t]m9al ( ! filam5t to "o po/ ( ! rheo/at & ! o!r po/ ( ?is to ! - or negative side ( ! ,a batt]y4 ,to ! electrode ( ! ,a batt]y connect ! - or z9c pole ( ! ,b batt]y & connect ! or c>bon pole ( ! latt] ) "o po/ ( ! fix$ 4#jja micr(>ad cond5s]4 ,?is done connect "o t]m9al ( ! tickl] coil :i* is on ! rotor ( ! v>iomet] to ! plate ( ! detector & ! o!r t]m9al ( ! tickl] to ! o!r po/ ( ! 4#jja cond5s] & ar\nd ?is %unt y\r headphones4 ,or if y want to use "o or m amplify+ tubes connect ! circuit ( ! fir/ "o1 see ,fig4 #de1 to ! po/s on ei!r side ( ! fix$ cond5s] in/ead ( ! headphones4 ,a ,long ,wave ,receiv+ ,set4--,! vivid imag9ation ( ,jules ,v]ne nev] conceiv$ any?+ s fasc9at+ z ! reception ( messages )\t wires s5t out by /ations half way r\nd ! _w2 & 9 ^! days ( high p[] cableless /ations on ! five cont95ts y c li/5-9 to ! messages & he> :at is be+ s5t out by ! ,lyons1 ,p>is & o!r ,fr5* /ations1 by ,great ,brita91 ,italy1 ,g]many & ev5 f> (f ,russia & ,japan4 ,a long wave set = receiv+ ^! /ations mu/ be able to tune to wave l5g?s up to #bj1jjj met]s4 ,diff]+ f ! way 9 :i* ! reg5]ative action ( ! %ort wave sets describ$ 9 ! prec$+ *apt] is secur$ & :i* dep5ds on a tickl] coil & ! c\pl+ action ( ! detector 9 ?is long wave set1 ,footnote3 ,all ( ! %ort wave & int]m$iate wave receiv]s describ$1 are connect$ up accord+ to ! wir+ diagram us$ by ! ,a4 ,h4 ,grebe ,company1 ,ri*mond ,hill1 ,long ,isl&1 ,n4 ,y4 ?is action is obta9$ by ! use ( a tickl] coil 9 ! plate circuit :i* is inductively c\pl$ to ! grid circuit & ?is fe$s back ! necess>y am\nt ( curr5t4 ,?is is a v good way to connect up ! circuits = ! reason t3 7#a7 ! wir+ is simplifi$1 & 7#b7 x gives a s+le v>iable adju/m5t = ! entire range ( wave l5g?s ! receptor is int5d$ to cov]4 ,! ,p>ts & ,h[ to ,connect ,!m ,up4--,! two *ief features z f> z ! p>ts are conc]n$ ( ?is long wave l5g? receiv+ set are 7#a7 ! v>iable cond5s]s1 & 7#b7 ! tun+ inductance coils4 ,! v>iable cond5s] us$ 9 s]ies ) ! a]ial wire sy/em has #bf plates & is equal to a capacitance ( 4#jjjh mfd4 :i* is ! normal a]ial capacitance4 ,! cond5s] us$ 9 ! second>y coil circuit has #ad plates & ?is is equal to a capacitance ( 4#jjjd mfd4 ,!re are a numb] ( inductance coils & ^! are arrang$ s t !y c be connect$ 9 or cut out & comb9ations are ?us =m$ :i* give a high effici5cy & yet all[ !m to be compactly m\nt$4 ,! inductance coils ( ! a]ial wire sy/em & ^? ( ! second>y coil circuit are practically alike4 ,= wave l5g?s up to #b1bjj met]s bank litz-w\nd coils are us$ & ^! are w\nd up 9 #b1 #d & #f banks 9 ord] to give ! prop] degree ( c\pl+ & inductance values4 ,:]e wave l5g?s ( m ?an #b1bjj met]s are to be receiv$ coto-coils are us$ z ^! are ! la/ ^w 9 inductance coil design1 & are especially adapt$ = m$ium z well z long wave l5g?s4 ,footnote3 ,c be _h ( ! ,coto ,coil ,co41 ,provid5ce1 ,r4 ,i4 ,^! v>i\s coils are cut 9 & out by means ( two five-po9t swit*es :i* are provid$ ) auxili>y lev]s & contactors = dead-end+ ! "r am\nt ( ! coils4 ,9 cutt+ 9 coils = increas$ wave l5g?s1 t is f #aj1jjj to #bj1jjj met]s1 all ( ! coils ( ! a]ial are connect$ 9 s]ies z well z all ( ! coils ( ! second>y circuit4 ,! connections = a long wave receptor are %[n 9 ! wir+ diagram 9 ,fig4 #ei4 ,illu/ration3 ,fig4 #ei4--,wir+ ,diagram ,%[+ ,long ,wave ,receptor ) ,v>ioc\pl]s & ,bank-w\nd ,inductance ,coils ,,*apt] ,,xiii ,,het]odyne ,,or ,,beat ,,long ,,wave ,,telegraph ,,receiv+ ,,set ,any ( ! receiv+ sets describ$ 9 ! =ego+ *apt]s w respond to ei!r3 7#a7 a wireless telegraph transmitt] t uses a sp>k gap & :i* s5ds out p]iodic electric waves1 or to 7#b7 a wireless telephone transmitt] t uses an arc or a vacuum tube oscillator & :i* s5ds out cont9u\s electric waves4 ,to receive wireless telegraph signals1 h[ev]1 f a transmitt] t uses an arc or a vacuum tube oscillator & :i* s5ds out cont9u\s waves1 ei!r ! transmitt] or ! receptor mu/ be s con/ruct$ t ! cont9u\s waves w be brok5 up into gr\ps ( audio frequ5cy & ?is is done 9 sev]al diff]5t ways4 ,!re are f\r diff]5t ways employ$ at ! pres5t "t to break up ! cont9u\s waves ( a wireless telegraph transmitt] into gr\ps & ^! are3 7a7 ! het]odyne1 or beat1 me?od1 9 :i* waves ( diff]5t l5g?s are impress$ on ! receiv$ waves & s produces beats2 7b7 ! tikk]1 or *opp] me?od1 9 :i* ! high frequ5cy curr5ts are rapidly brok5 up2 7c7 ! v>iable cond5s] me?od1 9 :i* ! movable plates are made to rapidly rotate2 7d7 ! tone :eel1 or frequ5cy trans=m]1 z x is (t5 call$1 & :i* is really a modifi$ =m ( & an improvem5t on ! tikk]4 ,! het]odyne me?od w be describ$ 9 ?is *apt]4 ,:at ! ,het]odyne or ,beat ,me?od ,is4--,! ^w het]odyne 0 co9$ f ! ,greek words het]os :i* means o!r1 or diff]5t1 & dyne :i* means p[]2 9 o!r words x means :5 us$ 9 connection ) a wireless receptor t ano!r & diff]5t high frequ5cy curr5t is us$ besides ! "o t is receiv$ f ! s5d+ /ation4 ,9 music a beat means a regul>ly recurr5t swell+ caus$ by ! re9=cem5t ( a s\nd & ?is is set up by ! int]f]5ce ( s\nd waves :i* h slightly diff]5t p]iods ( vibration z1 = in/ance1 :5 two tones take place t are n q 9 tune ) ea* o!r4 ,?is1 !n1 is ! pr9ciple ( ! het]odyne1 or beat1 receptor4 ,9 ! het]odyne1 or beat me?od1 sep>ate su/a9$ oscillations1 t are j ab\t z /rong z ^? ( ! incom+ waves1 are set up 9 ! receiv+ circuits & _! frequ5cy is j a little high] or a little l[] ?an ^? t are set up by ! waves receiv$ f ! di/ant transmitt]4 ,! result is t ^! oscillations ( diff]5t frequ5cies int]f]e & re9=ce ea* o!r :5 beats are produc$1 ! p]iod ( :i* is sl[ en\gh to be he>d 9 ! headphones1 h5ce ! incom+ signals c be he>d only :5 waves f ! s5d+ /ation are be+ receiv$4 ,a full] explanation ( h[ ?is is done w be f\nd 9 ,*apt] ,,xv4 ,! ,autodyne or ,self-,het]odyne ,long-,wave ,receiv+ ,set4--,?is is ! simple/ type ( het]odyne receptor & x w receive p]iodic waves f sp>k telegraph transmitt]s or cont9u\s waves f an arc or vacuum tube telegraph transmitt]4 ,9 ?is type ( receptor ! detector tube itself is made to set up ! het]odyne oscillations :i* int]f]e ) ^? t are produc$ by ! incom+ waves t are a little out ( tune ) x4 ,) a long wave autodyne1 or self-het]odyne receptor1 z ?is type is call$1 & a two-/ep audio-frequ5cy amplifi] y c cle>ly he> _m ( ! cableless /ations ( ,europe & o!rs t s5d out long waves4 ,= receiv+ long wave /ations1 h[ev]1 y mu/ h a long a]ial--a s+le wire #bjj or m feet 9 l5g? w d--& ! high] x is ! l\d] w be ! signals4 ,:]e x is n possible to put ! a]ial up a hundr$ feet or m above ! gr\nd1 y c use a l[] "o & /ill get messages 9 ,int]national ,morse fairly /rong4 ,! ,p>ts & ,connections ( an ,autodyne1 or ,self-,het]odyne1 ,receiv+ ,set4--,= ?is long wave receiv+ set y w ne$3 7#a7 "o v>ioc\pl] ) ! prim>y coil w\nd on ! /ator & ! second>y coil & tickl] coil w\nd on ! rotor1 or y c use ?ree honeycomb or o!r good compact coils ( ! longe/ wave y want to receive1 a table ( :i* is giv5 9 ,*apt] ,,xii2 7#b7 two 4#jja mfd4 v>iable cond5s]s2 7#c7 "o 4#jjje mfd4 v>iable cond5s]2 7#d7 "o 4#e to #b megohm grid leak resi/ance2 7#e7 "o vacuum tube detector2 7#f7 "o ,a batt]y2 7#g7 "o rheo/at2 7#h7 "o ,b batt]y2 7#i7 "o pot5tiomet]2 7#aj7 "o 4#jja mfd4 fix$ cond5s] & 7#aa7 "o pair ( headphones4 ,= ! two-/ep amplifi] y mu/1 ( c\rse1 h besides ! above p>ts ! amplifi] tubes1 v>iable cond5s]s1 batt]ies rheo/ats1 pot5tiomet]s & fix$ cond5s]s z expla9$ 9 ,*apt] ,,ix4 ,! connections = ! autodyne1 or self-het]odyne1 receiv+ set are %[n 9 ,fig4 #fj4 ,illu/ration3 ,fig4 #fj4--,wir+ ,diagram ( ,long ,wave ,antodyne1 or ,self-,het]odyne ,receptor4 ,! ,sep>ate ,het]odyne ,long ,wave ,receiv+ ,set4--,?is is a bett] long wave receptor ?an ! self het]odyne set describ$ above = receiv+ wireless telegraph signals s5t out by a cont9u\s long wave transmitt]4 ,! great advantage ( us+ a sep>ate vacuum tube to g5]ate ! het]odyne oscillations is t y c make ! frequ5cy ( ! oscillations j :at y want x to be & h5ce y c make x a little high] or a little l[] ?an ! oscillations set up by ! receiv$ waves4 ,! ,p>ts & ,connections ( a ,sep>ate ,het]odyne ,long ,wave ,receiv+ ,set4--,! p>ts requir$ = ?is long wave receiv+ set are3 7#a7 f\r honeycomb or o!r good compact inductance coils ( ! longe/ wave l5g? t y want to receive2 7#b7 ?ree 4#jja mfd4 v>iable cond5s]s2 7#c7 "o 4#jjje mfd4 v>iable cond5s]2 7#d7 "o #a megohm grid leak resi/ance2 7#e7 "o vacuum tube detector2 7#f7 "o ,a batt]y2 7#g7 two rheo/ats2 7#h7 two ,b batt]ies1 "o ( :i* is suppli$ ) taps2 7#i7 "o pot5tiomet]2 7#aj7 "o vacuum tube amplifi]1 = sett+ up ! het]odyne oscillations2 7#aa7 a pair ( headphones & 7#ab7 all ( ! p>ts = a two-/ep amplifi] z detail$ 9 ,*apt] ,,ix1 t is if y are go+ to use amplifi]s4 ,! connections are %[n 9 ,fig4 #fa4 ,illu/ration3 ,fig4 #fa4--,wir+ ,diagram ( ,long ,wave ,sep>ate ,het]odyne ,receiv+ ,set4 ,9 us+ ei!r ( ^! het]odyne receiv]s be sure to c>efully adju/ ! ,b batt]y by means ( ! pot5tiomet]4 ,footnote3 ,! amplifi] tube 9 ?is case is us$ z a g5]ator ( oscillations4 ,,*apt] ,,xiv ,,headphones ,,& ,,l\d ,,speak]s ,wireless ,headphones4--,a telephone receiv] = a wireless receiv+ set is made exactly on ! same pr9ciple z an ord9>y ,bell telephone receiv]4 ,! only diff]5ce betwe5 !m is t ! =m] is made flat & compact s t a pair ( !m c be fa/5$ toge!r ) a b& & worn on ! head 7:5 x is call$ a headset71 :ile ! latt] is long & cyl9drical s t x c be held to ! e>4 ,a fur!r diff]5ce betwe5 !m is t ! wireless headphone is made z s5sitive z possible s t x w respond to v feeble curr5ts1 :ile ! ord9>y telephone receiv] is f> f be+ s5sitive & w respond only to comp>atively l>ge curr5ts4 ,h[ a ,bell ,telephone ,receiv] ,is ,made4--,an ord9>y telephone receiv] consi/s ( ?ree *ief p>ts & ^! are3 7#a7 a h>d-rubb]1 or composition1 %ell & cap1 7#b7 a p]man5t /eel b> magnet on "o end ( :i* is w\nd a coil ( f9e insulat$ copp] wire1 & 7#c7 a s(t iron disk1 or diaphragm1 all ( :i* are %[n 9 ! cross-section 9 ,fig4 #fb4 ,! b> magnet is securely fix$ inside ( ! h&le s t ! outside end comes to )9 ab\t #a_/cb ( an in* ( ! diaphragm :5 ?is is laid on top ( ! %ell & ! cap is screw$ on4 ,illu/ration3 ,fig4 #fb4--;,cross-section ( ,bell telephone ,receiv]4 ,illu/ration3 orig9al ,und]wood & ,und]wood4 ,alex&] ,graham ,bell1 ,inv5tor ( ! ,telephone1 n[ an ard5t ,radio ,en?usia/4 ,! ends ( ! coil ( wire are connect$ ) two b9d+ po/s :i* are 9 ! end ( ! %ell1 b are %[n 9 ! picture at ! sides = ! sake ( cle>ness4 ,?is coil usually has a resi/ance ( ab\t #ge ohms & ! mean+ ( ! ohmic resi/ance ( a receiv] & its be>+ on ! s5sitiv5ess ( x w be expla9$ a little f>!r along4 ,aft] ! disk1 or diaphragm1 :i* is g5]ally made ( ?91 s(t %eet iron t has be5 t9n$ or japann$1 ,footnote3 ,a disk ( photographic t9-type plate is g5]ally us$4 is plac$ ov] ! end ( ! magnet1 ! cap1 :i* has a small op5+ 9 x1 is screw$ on & ! receiv] is ready to use4 ,h[ a ,wireless ,headphone ,is ,made4--,= wireless "w a receiv] ( ! wat*-case type is us$ & ne>ly always two su* receiv]s are connect$ ) a headb&4 ,x consi/s ( a p]man5t b> magnet b5t s t x w fit into ! %ell ( ! receiv] z %[n at ,a 9 ,fig4 #fc4 ,illu/ration3 ,fig4 #fc4--,wireless ,headphone4 ,! ends ( ?is magnet1 :i* are call$ poles1 are b5t up1 & h5ce ?is type is call$ a bipol> receiv]4 ,! magnets are w\nd ) f9e insulat$ wire z be=e & ! diaphragm is held securely 9 place ov] !m by screw+ on ! cap4 ,ab\t ,resi/ance1 ,turns ( ,wire & ,s5sitivity ( ,headphones4--,if y are a beg9n] 9 wireless y w he> ^? :o are exp]i5c$ speak ( a telephone receiv] z hav+ a resi/ance ( #ge ohms1 #a1jjj ohms1 #b1jjj or #c1jjj ohms1 z ! case may be2 f ?is y w ga!r t ! high] ! resi/ance ( ! wire on ! magnets ! m s5sitive ! receiv] is4 ,9 a s5se ?is is true1 b x is n ! resi/ance ( ! magnet coils t makes x s5sitive1 9 fact1 x cuts d[n ! curr5t1 b x is ! numb] ( turns ( wire on !m t det]m9es its s5sitiv5ess2 x is easy to see t ?is is s1 = ! l>g] ! numb] ( turns ! m (t5 w ! same curr5t fl[ r\nd ! cores ( ! magnet & s magnetize !m to a great] ext5t4 ,b to w9d a l>ge numb] ( turns ( wire close en\gh to ! cores to be effective ! wire mu/ be v small & s1 ( c\rse1 ! high] ! resi/ance w be4 ,n[ ! wire us$ = w9d+ good receiv]s is usually ,no4 #dj1 & ?is has a diamet] ( 4#jjca in*2 consequ5tly1 :5 y "k ! ohmic resi/ance y get an idea ( ! numb] ( turns ( wire & f ?is y ga!r 9 a g5]al way :at ! s5sitivity ( ! receiv] is4 ,a receiv] t is s5sitive en\gh = wireless "w %\ld be w\nd to n less ?an #a1jjj ohms 7?is means ea* e> phone71 :ile ^? ( a bett] grade are w\nd to z high z #c1jjj ohms = ea* "o4 ,a high-grade headset is %[n 9 ,fig4 #fd4 ,ea* phone ( a headset %\ld be w\nd to ! same resi/ance1 & ^! are connect$ 9 s]ies z %[n4 ,:]e two or m headsets are us$ ) "o wireless receiv+ set !y mu/ all be ( ! same resi/ance & connect$ 9 s]ies1 t is1 ! coils ( "o head set are connect$ ) ! coils ( ! next head set & s on to =m a cont9u\s circuit4 ,illu/ration3 ,fig4 #fd4--,wireless ,headphone4 ,! ,imp$ance ( ,headphones4--,:5 a curr5t is fl[+ ?r\gh a circuit ! mat]ial ( :i* ! wire is made n only opposes its passage--?is is call$ its ohmic resi/ance--b a c\nt]-electromotive =ce to ! curr5t is set up due to ! inductive effects ( ! curr5t on itself & ?is is call$ imp$ance4 ,:]e a wire is w\nd 9 a coil ! imp$ance ( ! circuit is increas$ & :]e an alt]nat+ curr5t is us$ ! imp$ance gr[s great] z ! frequ5cy gets high]4 ,! imp$ance ( ! magnet coils ( a receiv] is s great = high frequ5cy oscillations t ! latt] _c pass ?r\gh !m2 9 o!r words1 !y are *ok$ (f4 ,h[ ! ,headphones ,"w4--,z y w see f ! cross-sections 9 ,figs4 #fb & #fc !re is no connection1 electrical or me*anical1 betwe5 ! diaphragm & ! o!r p>ts ( ! receiv]4 ,n[ :5 ei!r feeble oscillations1 :i* h be5 rectifi$ by a detector1 or small curr5ts f a ,b batt]y1 fl[ ?r\gh ! magnet coils ! p]man5t /eel magnet is en]giz$ to a great] ext5t ?an :5 no curr5t is fl[+ ?r\gh x4 ,?is add$ magnetic en]gy makes ! magnet attract ! diaphragm m ?an x w\ld d by its own =ce4 ,if1 on ! o!r h&1 ! curr5t is cut (f ! pull ( ! magnet is less5$ & z its attraction = ! diaphragm is decreas$ ! latt] spr+s back to its orig9al position4 ,:5 v>y+ curr5ts fl[ ?r\gh ! coils ! diaphragm vibrates accord+ly & s5ds out s\nd waves4 ,ab\t ,l\d ,speak]s4--,! simple/ ac\/ic in/rum5t ev] inv5t$ is ! megaphone1 :i* latt] is a ,greek ^w mean+ great s\nd4 ,x is a v primitive device & our ,indians made x out ( bir*-b>k be=e ,columbus discov]$ ,am]ica4 ,9 its simple/ =m x consi/s ( a cone-%ap$ horn & z ! speak] talks into ! small end ! conc5trat$ s\nd waves pass out ( ! l>ge end 9 :atev] direction x is held4 ,n[ a l\d speak] ( :atev] k9d consi/s ( two *ief p>ts & ^! are3 7#a7 a telephone receiv]1 & 7#b7 a megaphone1 or horn z x is call$4 ,a l\d speak] :5 connect$ ) a wireless receiv+ set makes x possible = a room1 or an auditorium1 full ( p1 or an outdoor cr[d1 to he> :at is be+ s5t out by a di/ant /ation in/ead ( be+ limit$ to a few p]sons li/5+-9 ) headphones4 ,to use a l\d speak] y %\ld h a vacuum tube detector receiv+ set & ?is mu/ be provid$ ) a "o-/ep amplifi] at lea/4 ,to get really good results y ne$ a two-/ep amplifi] & !n en]gize ! plate ( ! second vacuum tube amplifi] ) a #ajj volt ,b batt]y2 or if y h a ?ree-/ep amplifi] !n use ! high voltage on ! plate ( ! ?ird amplifi] tube4 ,amplify+ tubes are made to /& a plate pot5tial ( #ajj volts & ?is is ! k9d y mu/ use4 ,n[ x may seem curi\s1 b :5 ! curr5t fl[s ?r\gh ! coils ( ! telephone receiv] 9 "o direction x gives bett] results ?an :5 x fl[s ?r\gh 9 ! o!r direction2 to f9d out ! way ! curr5t gives ! be/ results try x out bo? ways & ?is y c d by simply rev]s+ ! connections4 ,! ,simple/ ,type ( ,l\d ,speak]4--,?is l\d speak]1 :i* is call$1 ! ,arkay1 ,footnote3 ,made by ! ,riley-,klotz ,mfg4 ,co41 ,new>k1 ,n4 ,j4 w "w on a "o- or two-/ep amplifi]4 ,x consi/s ( a brass horn ) a curve 9 x & 9 ! bottom !re is an adapt]1 or frame1 ) a set screw 9 x s t y c fit 9 "o ( y\r headphones & ?is is all !re is to x4 ,! con/ruction is rigid en\gh to prev5t ov]tones1 or di/ortion ( spee* or music4 ,x is %[n 9 ,fig4 #fe4 ,illu/ration3 ,fig4 #fe4--;,arkay ,l\d ,speak]4 ,ano!r ,simple ,k9d ( ,l\d ,speak]4--,ano!r l\d speak]1 see ,fig4 #ff1 is kn[n z ! ,amplitone ,footnote3 ,made by ! ,am]ican ,patt]n1 ,f\ndry & ,ma*9e ,co41 #hb ,*ur* ,/reet1 ,n4 ,y4 ,c4 & x likewise makes use ( ! headphones z ! s\nd produc]4 ,?is device has a ca/ metal horn :i* improves ! quality ( ! s\nd1 & all y h to d is to slip ! headphones on ! inlet tubes ( ! horn & x is ready = use4 ,! two headphones n only give a long] volume ( s\nd ?an :]e a s+le "o is us$ b !re is a c]ta9 bl5d$ quality :i* results f "o phone smoo?+ out ! imp]fections ( ! o!r4 ,illu/ration3 ,fig4 #ff4--;,amplitone ,l\d ,speak]4 ,a ,?ird ,k9d ( ,simple ,l\d ,speak]4--,! op]ation ( ! ,amplitron1 ,footnote3 ,made by ! ,radio ,s]vice ,co41 #aaj ,w4 #dj? ,/reet1 ,n4 ,y4 z ?is l\d speak] is call$1 is slightly diff]5t f o!rs us$ = ! same purpose4 ,! s\nds set up by ! headphone are convey$ to ! apex ( an inv]t$ copp] cone :i* is #g in*es long & #aj in*es 9 diamet]4 ,"h x is reflect$ by a p>abolic mirror :i* greatly amplifies ! s\nds4 ,! amplification takes place )\t di/ortion1 ! s\nds rema9+ z cle> & crisp z :5 project$ by ! transmitt+ /ation4 ,by remov+ ! cap f ! receiv] ! %ell is screw$ into a receptacle on ! end ( ! l\d speak] & ! in/rum5t is ready = use4 ,x is pictur$ 9 ,fig4 #fg4 ,illu/ration3 ,fig4 #fg4--;,amplitron ,l\d ,speak]4 ,a ,sup] ,l\d ,speak]4--,?is l\d speak]1 :i* is kn[n z ! ,magnavox ,telemegafone1 0 ! in/rum5t us$ by ,lt4 ,h]b]t ,e4 ,metcalf1 #c1jjj feet 9 ! air1 & :i* />tl$ ! ,city ( ,wa%+ton on ,april #b1 #aiai1 by repeat+ ,presid5t ,wilson's ,victory ,loan ,message f an airplane 9 flight s t x 0 di/9ctly he>d by #bj1jjj p bel[4 ,?is wond]ful a*ievem5t 0 accompli%$ ?r\gh ! in/allation ( ! ,magnavox & amplifi]s 9 front ( ! ,treasury ,build+4 ,e ^w ,lt4 ,metcalf spoke into 8 wireless telephone transmitt] 0 caught & swell$ 9 volume by ! ,telemegafones bel[ & p]sons blocks away c\ld he> ! message pla9ly4 ,two k9ds ( ^! l\d speak]s are made & ^! are3 7#a7 a small l\d speak] = ! use ( op]ators s t headphones ne$ n be worn1 & 7#b7 a l>ge l\d speak] = auditorium & out-door audi5ces4 ,illu/ration3 orig9al ,und]wood & ,und]wood4 ,_w's ,l>ge/ ,l\d ,speak] ev] made4 ,in/all$ 9 ,lytle ,p>k1 ,c9c9nati1 ,ohio1 to p]mit ,presid5t ,h>d+'s ,address at ,po9t ,pleasant1 ,ohio1 dur+ ! ,grant ,c5t5>y ,celebration to be he>d )9 a radius ( "o squ>e4 ,ei!r k9d may be us$ ) a "o- or two-/ep amplifi] or ) a cascade ( half a doz5 amplifi]s1 accord+ to ! degree ( l\dness desir$4 ,! ,telemegafone itself is n an amplifi] 9 ! true s5se inasmu* z x conta9s no elem5ts :i* w locally increase ! incom+ curr5t4 ,x does1 h[ev]1 trans=m ! v>iable electric curr5ts ( ! wireless receiv+ set into s\nd vibrations 9 a mo/ wond]ful mann]4 ,a telemegafone ( ei!r k9d is =m$ (3 7#a7 a telephone receiv] ( l>ge proportions1 7#b7 a /ep-d[n induction coil1 & 7#c7 a #f volt /orage batt]y t en]gizes a p[]ful electromagnet :i* works ! diaphragm4 ,an electromagnet is us$ in/ead ( a p]man5t magnet & ?is is en]giz$ by a #f-volt /orage batt]y z %[n 9 ! wir+ diagram at ,a 9 ,fig4 #fh4 ,"o end ( ! core ( ?is magnet is fix$ to ! iron case ( ! speak] & toge!r ^! =m ! equival5t ( a horse%oe magnet4 ,a movable coil ( wire is support$ f ! c5t] ( ! diaphragm ! edge ( :i* is rigidly held betwe5 ! case & ! small end ( ! horn4 ,?is coil is plac$ ov] ! upp] end ( ! magnet & its t]m9als are connect$ to ! second>y ( ! induction coil4 ,n[ :5 ! coil is en]giz$ by ! curr5t f ! amplifi]s x & ! core act l a sol5oid 9 t ! coil t5ds to suck ! core into x2 b s9ce ! core is fix$ & ! coil is movable ! core draws ! coil d[n in/ead4 ,! result is t ) e v>iation ( ! curr5t t fl[s ?r\gh ! coil x moves up & d[n & pulls & pu%es ! diaphragm d[n & up ) x4 ,! l>ge amplitude ( ! vibrations ( ! latt] set up p[]ful s\nd waves :i* c be he>d sev]al blocks away f ! horn4 ,9 ?is way !n are ! fa9t incom+ signals1 spee* & music :i* are receiv$ by ! amplify+ receiv+ set reproduc$ & magnifi$ enorm\sly4 ,! ,telemegafone is %[n complete at ,b4 ,illu/ration3 ,fig4 #fh4--,magnavox ,l\d ,speak]4 ,,*apt] ,,xv ,,op]ation ,,( ,,vacuum ,,tube ,,receptors ,f ! =ego+ *apt]s y h se5 t ! vacuum tube c be us$ ei!r z a detector or an amplifi] or z a g5]ator ( electric oscillations1 z 9 ! case ( ! het]odyne receiv+ set4 ,to und]/& h[ a vacuum tube acts z a detector & z an amplifi] y mu/ fir/ "k :at electrons are4 ,! way 9 :i* ! vacuum tube sets up su/a9$ oscillations w be expla9$ 9 ,*apt] ,,xviii 9 connection ) ! ,op]ation ( ,vacuum ,tube ,transmitt]s4 ,:at ,electrons ,are4--,sci5ce tea*es u t masses ( matt] are made up ( molecules1 t ea* ( ^! is made up ( atoms1 & ea* ( ^!1 9 turn1 is made up ( a c5tral core ( positive p>ticles ( electricity surr\nd$ by negative p>ticles ( electricity z %[n 9 ! s*ematic diagram1 ,fig4 #fi4 ,! little black circles inside ! l>ge circle repres5t positive p>ticles ( electricity & ! little :ite circles outside ( ! l>ge circle repres5t negative p>ticles ( electricity1 or electrons z !y are call$4 ,illu/ration3 ,fig4 #fi4--,s*ematic ,diagram ( an ,atom4 ,x is ! numb] ( positive p>ticles ( electricity an atom has t det]m9es ! k9d ( an elem5t t is =m$ :5 en\gh atoms ( ! same k9d are jo9$ toge!r to build x up4 ,?us hydrog51 :i* is ! lighte/ kn[n elem5t1 has "o positive p>ticle = its nucleus1 :ile uranium1 ! heavie/ elem5t n[ kn[n1 has #ib positive p>ticles4 ,n[ be=e leav+ ! atom please note t x is z mu* small] ?an ! diagram z ! latt] is small] ?an our sol> sy/em4 ,:at ,is ,meant by ,ionization4--,a hydrog5 atom is n only light] b x is small] ?an ! atom ( any o!r elem5t :ile an electron is m ?an a ?\s& times small] ?an ! atom ( :i* x is a "p4 ,n[ z long z all ( ! electrons rema9 atta*$ to ! surface ( an atom its positive & negative *>ges are equaliz$ & x w1 !re=e1 be nei!r positive nor negative1 t is1 x w be p]fectly neutral4 ,:51 h[ev]1 "o or m ( its electrons are sep>at$ f x1 & !re are sev]al ways by :i* ?is c be done1 ! atom w %[ a positive *>ge & x is !n call$ a positive ion4 ,9 o!r words a positive ion is an atom t has lo/ "s ( its negative electrons :ile a negative ion is "o t has acquir$ "s additional negative electrons4 ,:5 a numb] ( electrons are be+ con/antly giv5 by ! atoms ( an elem5t1 :i* let u suppose is a metal1 & are be+ attract$ to atoms ( ano!r elem5t1 :i* we w say is also a metal1 a fl[ ( electrons takes place betwe5 ! two oppositely *>g$ elem5ts & =m a curr5t ( negative electricity z repres5t$ by ! arr[s at ,a 9 ,fig4 #gj4 ,illu/ration3 ,fig4 #gj4--;,action ( ,two-electrode ,vacuum ,tube4 ,:5 a /ream ( electrons is fl[+ betwe5 two metal elem5ts1 z a filam5t & a plate 9 a vacuum tube detector1 or an amplifi]1 !y act z c>ri]s = m negative electrons & ^! are suppli$ by a batt]y z we %all pres5tly expla94 ,x has always be5 cu/om>y = u to ?9k ( a curr5t ( electricity z fl[+ f ! positive pole ( a batt]y to ! negative pole ( x & h5ce we h call$ ?is ! direction ( ! curr5t4 ,s9ce ! electronic !ory has be5 evolv$ x has be5 %[n t ! electrons1 or negative *>ges ( electricity1 fl[ f ! negative to ! positive pole & t ! ioniz$ atoms1 :i* are m positive ?an negative1 fl[ 9 ! opposite direction z %[n at ,b4 ,h[ ,electrons are ,sep>at$ f ,atoms4--,! next "q t arises is h[ to make a metal ?r[ (f "s ( ! electrons ( ! atoms ( :i* x is =m$4 ,!re are sev]al ways t ?is c be done b 9 any ev5t ea* atom mu/ be giv5 a good1 h>d bl[4 ,a simple way to d ?is is to heat a metal to inc&esc5ce :5 ! atoms w bomb>d ea* o!r ) t]rific =ce & _m ( ! electrons w be knock$ (f & ?r[n out into ! surr\nd+ space4 ,b all1 or ne>ly all1 ( !m w return to ! atoms f :5ce !y came unless a means ( "s k9d is employ$ to attract !m to ! atoms ( "s o!r elem5t4 ,?is c be done by giv+ ! latt] piece ( metal a positive *>ge4 ,if n[ ^! two pieces ( metal are plac$ 9 a bulb f :i* ! air has be5 exhau/$ & ! fir/ piece ( metal is heat$ to brilliancy :ile ! second piece ( metal is kept positively electrifi$ !n a /ream ( electrons w fl[ betwe5 !m4 ,action ( ! ,two ,electrode ,vacuum ,tube4--,n[ 9 a vacuum tube detector a wire filam5t1 l t ( an inc&esc5t lamp1 is connect$ ) a batt]y & ?is =ms ! hot elem5t f :i* ! electrons are ?r[n (f1 & a metal plate ) a t]m9al wire secur$ to x is connect$ to ! positive or c>bon tap ( a dry batt]y2 n[ connect ! negative or z9c tap ( ?is ) "o end ( a telephone receiv] & ! o!r end ( ?is ) ! t]m9als ( ! filam5t z %[n at ,a 9 ,fig4 #ga4 ,if n[ y heat ! filam5t & hold ! phone to y\r e> y c he> ! curr5t f ! ,b batt]y fl[+ ?r\gh ! circuit4 ,illu/ration3 7,a7 & 7,b7 ,fig4 #ga4--;,h[ a ,two ,electrode ,tube ,acts z a ,relay or a ,detector4 ,illu/ration3 7,c7 ,fig4 #ga4--,only ! ,positive ,"p ( ,oscillations ,goes ?r\gh ! ,tube4 ,s9ce ! electrons are negative *>ges ( electricity !y are n only ?r[n (f by ! hot wire b !y are attract$ by ! positive *>g$ metal plate & :5 en\gh electrons pass1 or fl[1 f ! hot wire to ! plate !y =m a conduct+ pa? & s complete ! circuit :i* includes ! filam5t1 ! plate & ! ,b or plate batt]y1 :5 ! curr5t c !n fl[ ?r\gh x4 ,z ! numb] ( electrons t are ?r[n (f by ! filam5t is n great & ! voltage ( ! plate is n high ! curr5t t fl[s betwe5 ! filam5t & ! plate is always q small4 ,h[ ! ,two ,electrode ,tube ,acts z a ,detector4--,z ! action ( a two electrode tube z a detector ,footnote3 ,! ?ree electrode vacuum tube has entirely tak5 ! place ( ! two electrode type4 is simpl] ?an t ( ! ?ree electrode vacuum tube we %all describe x fir/4 ,! two electrode vacuum tube 0 fir/ made by ,mr4 ,edison :5 he 0 work+ on ! inc&esc5t lamp b t x w\ld s]ve z a detector ( electric waves 0 discov]$ by ,pr(4 ,flem+1 ( ,ox=d ,univ]sity1 ,london4 ,z a matt] ( fact1 x is n really a detector ( electric waves1 b x acts z3 7#a7 a rectifi] ( ! oscillations t are set up 9 ! receiv+ circuits1 t is1 x *anges !m into pulsat+ direct curr5ts s t !y w fl[ ?r\gh & affect a telephone receiv]1 & 7#b7 x acts z a relay & ! feeble receiv$ oscillat+ curr5t controls ! l>g] direct curr5t f ! ,b batt]y 9 v mu* ! same way t a telegraph relay does4 ,?is latt] relay action w be expla9$ :5 we come to its op]ation z an amplifi]4 ,we h j le>n$ t :5 ! /ream ( electrons fl[ f ! hot wire to ! cold positive plate 9 ! tube !y =m a conduct+ pa? ?r\gh :i* ! batt]y curr5t c fl[4 ,n[ :5 ! electric oscillations surge ?r\gh ! clos$ oscillation circuit1 :i* includes ! second>y ( ! tun+ coil1 ! v>iable cond5s]1 ! filam5t & ! plate z %[n at ,b 9 ,fig4 #ga ! positive "p ( !m passes ?r\gh ! tube easily :ile ! negative "p _c get ?r\gh1 t is1 ! top1 or positive1 "p ( ! wave-=m rema9s intact :ile ! l[]1 or negative1 "p is cut (f z %[n 9 ! diagram at ,c4 ,z ! receiv$ oscillations are ei!r brok5 up into wave tra9s ( audio frequ5cy by ! telegraph transmitt] or are modulat$ by a telephone transmitt] !y c>ry ! l>g] impulses ( ! direct curr5t f ! ,b batt]y along ) !m & ^! fl[ ?r\gh ! headphones4 ,?is is ! reason ! vacuum tube amplifies z well z detects4 ,h[ ! ,?ree ,electrode ,tube ,acts z a ,detector4--,! vacuum tube z a detector has be5 made v mu* m s5sitive by ! use ( a ?ird electrode %[n 9 ,fig4 #gb4 ,9 ?is type ( vacuum tube ! ?ird electrode1 or grid1 is plac$ betwe5 ! filam5t & ! plate & ?is controls ! numb] ( electrons fl[+ f ! filam5t to ! plate2 9 pass+ betwe5 ^! two electrodes !y h to g ?r\gh ! holes =m$ by ! grid wires4 ,illu/ration3 7,a7 & 7,b7 ,fig4 #gb4--;,h[ ! ,positive & ,negative ,voltages ( ,oscillations ,act on ! ,electrons4 ,illu/ration3 7,c7 ,fig4 #gb4--;,h[ ! ,?ree ,electrode ,tube ,acts z a ,detector & ,amplifi]4 ,illu/ration3 7,d7 ,fig4 #gb4--;,h[ ! ,oscillations ,control ! ,fl[ ( ! ,batt]y ,curr5t ?r\gh ! ,tube4 ,if n[ ! grid is *>g$ to a high] negative voltage ?an ! filam5t ! electrons w be /opp$ by ! latt]1 see ,a1 ?\gh "s ( !m w g ?r\gh to ! plate because !y travel at a high rate ( spe$4 ,! high] ! negative *>ge on ! grid ! small] w be ! numb] ( electrons t w rea* ! plate &1 ( c\rse1 ! small] w be ! am\nt ( curr5t t w fl[ ?r\gh ! tube & ! headphones f ! ,b batt]y4 ,on ! o!r h& if ! grid is *>g$ positively1 see ,b1 !n m electrons w /rike ! plate ?an :5 ! grid is n us$ or :5 x is negatively *>g$4 ,b :5 ! ?ree electrode tube is us$ z a detector ! oscillations set up 9 ! circuits *ange ! grid alt]nately f negative to positive z %[n at ,c & h5ce ! voltage ( ! ,b batt]y curr5t t is all[$ to fl[ ?r\gh ! detector f ! plate to ! filam5t rises & falls 9 unison ) ! voltage ( ! oscillat+ curr5ts4 ,! way ! positive & negative voltages ( ! oscillations :i* are set up by ! incom+ waves1 en]gize ! grid2 h[ ! oscillator tube clips (f ! negative p>ts ( !m1 &1 f9ally1 h[ ^! c>ry ! batt]y curr5t ?r\gh ! tube are %[n graphically by ! curves at ,d4 ,h[ ! ,vacuum ,tube ,acts z an ,amplifi]4--,if y connect up ! filam5t & ! plate ( a ?ree electrode tube ) ! batt]ies & d n connect 9 ! grid1 y w f9d t ! electrons :i* are ?r[n (f by ! filam5t w n get f>!r ?an ! grid reg>dless ( h[ high ! voltage is t y apply to ! plate4 ,?is is due to ! fact t a l>ge numb] ( electrons :i* are ?r[n (f by ! filam5t /rike ! grid & give x a negative *>ge1 & consequ5tly1 !y _c get any f>!r4 ,s9ce ! electrons d n rea* ! plate ! curr5t f ! ,b batt]y _c fl[ betwe5 x & ! filam5t4 ,n[ ) a prop]ly design$ amplifi] tube a v small negative voltage on ! grid w keep a v l>ge positive voltage on ! plate f s5d+ a curr5t ?r\gh ! tube1 & oppositely1 a v small positive voltage on ! grid w let a v l>ge plate curr5t fl[ ?r\gh ! tube2 ?is be+ true x foll[s t any small v>iation ( ! voltage f positive to negative on ! grid & ! o!r way ab\t w v>y a l>ge curr5t fl[+ f ! plate to ! filam5t4 ,9 ! ,morse telegraph ! relay p]mits ! small curr5t t is receiv$ f ! di/ant s5d+ /ation to en]gize a pair ( magnets1 & ^! draw an armature t[>d !m & close a second circuit :5 a l>ge curr5t f a local batt]y is available = work+ ! s\nd]4 ,! amplifi] tube is a v>iable relay 9 t ! feeble curr5ts set up by ! incom+ waves con/antly & proportionately v>y a l>ge curr5t t fl[s ?r\gh ! headphones4 ,?is !n is ! pr9ciple on :i* ! amplify+ tube works4 ,! ,op]ation ( a ,simple ,vacuum ,tube ,receiv+ ,set4--,! way a simple vacuum tube detector receiv+ set works is l ?is3 :5 ! filam5t is heat$ to brilliancy x gives (f electrons z previ\sly describ$4 ,n[ :5 ! electric waves imp+e on ! a]ial wire !y set up oscillations 9 x & ^! surge ?r\gh ! prim>y coil ( ! loose c\pl$ tun+ coil1 a diagram ( :i* is %[n at ,b 9 ,fig4 #da4 ,! en]gy ( ^! oscillations sets up oscillations ( ! same frequ5cy 9 ! second>y coil & ^! high frequ5cy curr5ts ^: voltage is fir/ positive & !n negative1 surge 9 ! clos$ circuit :i* includes ! second>y coil & ! v>iable cond5s]4 ,at ! same "t ! alt]nat+ positive & negative voltage ( ! oscillat+ curr5ts is impress$ on ! grid2 at ea* *ange f to - & back aga9 x all[s ! electrons to /rike ! plate & !n %uts !m (f2 z ! electrons =m ! conduct+ pa? betwe5 ! filam5t & ! plate ! l>g] direct curr5t f ! ,b batt]y is p]mitt$ to fl[ ?r\gh ! detector tube & ! headphones4 ,op]ation ( a ,reg5]ative ,vacuum ,tube ,receiv+ ,set4--,by fe$+ back ! pulsat+ direct curr5t f ! ,b batt]y ?r\gh ! tickl] coil x sets up o!r & /rong] oscillations 9 ! second>y ( ! tun+ coil :5 ^! act on ! detector tube & increase its s5sitiv5ess to a rem>kable ext5t4 ,! reg5]ative1 or fe$ back1 action ( ! receiv+ circuits us$ w be easily und]/ood by ref]r+ back to ,b 9 ,fig4 #dg4 ,:5 ! waves set up oscillations 9 ! prim>y ( ! tun+ coil ! en]gy ( !m produces l oscillations 9 ! clos$ circuit :i* includes ! second>y coil & ! cond5s]2 ! alt]nat+ positive & negative voltages ( ^! are impress$ on ! grid & ^!1 z we h se5 be=e1 cause simil> v>iations ( ! direct curr5t f ! ,b batt]y :i* acts on ! plate & :i* fl[s betwe5 ! latt] & ! filam5t4 ,?is v>y+ direct curr5t1 h[ev]1 is made to fl[ back ?r\gh ! ?ird1 or tickl] coil ( ! tun+ coil & sets up 9 ! second>y coil & circuits o!r & l>g] oscillat+ curr5ts & ^! augm5t ! action ( ! oscillations produc$ by ! incom+ waves4 ,^! extra & l>g] curr5ts :i* are ! result ( ! fe$back !n act on ! grid & cause /ill l>g] v>iations ( ! curr5t 9 ! plate voltage & h5ce ( ! curr5t ( ! ,b batt]y t fl[s ?r\gh ! detector & ! headphones4 ,at ! same "t ! tube keeps on respond+ to ! feeble electric oscillations set up 9 ! circuits by ! incom+ waves4 ,?is reg5]ative action ( ! batt]y curr5t augm5ts ! orig9al oscillations _m times & h5ce produce s\nds 9 ! headphones t are _m times great] ?an :]e ! vacuum tube detector alone is us$4 ,op]ation ( ,autodyne & ,het]odyne ,receiv+ ,sets4--,on page #aji ,*apt] ,,vii we discuss$ & at ,a 9 ,fig4 #cf is %[n a picture ( two tun+ =ks m\nt$ on s\nd+ boxes to illu/rate ! pr9ciple ( electrical tun+4 ,:5 a pair ( ^! =ks are made to vibrate exactly ! same numb] ( times p] second !re w be a cond5sation ( ! air betwe5 !m & ! s\nd waves t are s5t out w be augm5t$4 ,b if y adju/ "o ( ! =ks s t x w vibrate #bef times a second & ! o!r =k s t x w vibrate #bfj times a second !n !re w be a phase diff]5ce betwe5 ! two sets ( waves & ! latt] w augm5t ea* o!r #d times e second & y w he> ^! ris+ & fall+ s\nds z beats4 ,n[ electric oscillations set up 9 two circuits t are c\pl$ toge!r act 9 exactly ! same way z s\nd waves produc$ by two tun+ =ks t are close to ea* o!r4 ,s9ce ?is is true if y tune "o ( ! clos$ circuits s t ! oscillations 9 x w h a frequ5cy ( a #a1jjj1jjj & tune ! o!r circuit s t ! oscillations 9 x h a frequ5cy ( #a1jja1jjj a second !n ! oscillations w augm5t ea* o!r #a1jjj times e second4 ,z ^! ris+ & fall+ curr5ts act on ! pulsat+ curr5ts f ! ,b batt]y :i* fl[ ?r\gh ! detector tube & ! headphones y w he> !m z beats4 ,a graphic repres5tation ( ! oscillat+ curr5ts set up by ! incom+ waves1 ^? produc$ by ! het]odyne oscillator & ! beats !y =m is %[n 9 ,fig4 #gc4 ,to produce ^! beats a receptor c use3 7#a7 a s+le vacuum tube = sett+ up oscillations ( bo? frequ5cies :5 x is call$ an autodyne1 or self-het]odyne receptor1 or 7#b7 a sep>ate vacuum tube = sett+ up ! oscillations = ! second circuit :5 x is call$ a het]odyne receptor4 ,illu/ration3 ,fig4 #gc4--;,h[ ! ,het]odyne ,receptor ,works4 ,! ,autodyne1 or ,self-,het]odyne ,receiv+ ,set4--,:]e only "o vacuum tube is us$ = produc+ bo? frequ5cies y ne$ only a reg5]ative1 or fe$-back receptor2 !n y c tune ! a]ial wire sy/em to ! incom+ waves & tune ! clos$ circuit ( ! second>y coil s t x w be out ( /ep ) ! =m] by #a1jjj oscillations p] second1 m or less1 ! exact numb] does n matt] 9 ! lea/4 ,f ?is y w see t any reg5]ative set c be us$ = autodyne1 or self-het]odyne1 reception4 ,! ,sep>ate ,het]odyne ,receiv+ ,set4--,! bett] way1 h[ev]1 is to use a sep>ate vacuum tube = sett+ up ! het]odyne oscillations4 ,! latt] !n act on ! oscillations t are produc$ by ! incom+ waves & :i* en]gize ! grid ( ! detector tube4 ,note t ! vacuum tube us$ = produc+ ! het]odyne oscillations is a g5]ator ( electric oscillations2 ! latt] are impress$ on ! detector circuits ?r\gh ! v>iable c\pl+1 ! second>y ( :i* is 9 s]ies ) ! a]ial wire z %[n 9 ,fig4 #gd4 ,! way 9 :i* ! tube acts z a g5]ator ( oscillations w be told 9 ,*apt] ,,xviii4 ,illu/ration3 ,fig4 #gd4--,sep>ate ,het]odyne ,oscillator4 ,,*apt] ,,xvi ,,cont9u\s ,,wave ,,telegraph ,,transmitt+ ,,sets ,,) ,,direct ,,curr5t ,9 ! fir/ "p ( ?is book we le>n$ ab\t sp>k-gap telegraph sets & h[ ! oscillations !y set up are damp$ & ! waves !y s5d out are p]iodic4 ,9 ?is & ! next *apt] we %all f9d out h[ vacuum tube telegraph transmitt]s are made & h[ !y set up oscillations t are su/a9$ & radiate waves t are cont9u\s4 ,s5d+ wireless telegraph messages by cont9u\s waves has _m features to recomm5d x z aga9/ s5d+ !m by p]iodic waves & among ! mo/ important ( ^! are t ! transmitt] c be3 7#a7 m %>ply tun$1 7#b7 x w s5d signals f>!r ) ! same am\nt ( p[]1 & 7#c7 x is noiseless 9 op]ation4 ,! disadvantage\s features are t3 7#a7 a batt]y curr5t is n satisfactory1 7#b7 its circuits are some:at m complicat$1 & 7#c7 ! oscillator tubes burn out occasionally4 ,!re is1 h[ev]1 a gr[+ t5d5cy among amateurs to use cont9u\s wave transmitt]s & !y are c]ta9ly m up-to-date & int]e/+ ?an sp>k gap sets4 ,n[ !re are two practical ways by :i* cont9u\s waves c be set up = s5d+ ei!r telegraphic signals or telephonic spee* & music & ^! are )3 7a7 an oscillation arc lamp1 & 7b7 a vacuum tube oscillator4 ,! oscillation arc 0 ! e>lie/ kn[n way ( sett+ up su/a9$ oscillations1 & x is n[ l>gely us$ = comm]cial high p[]1 long di/ance "w4 ,b s9ce ! vacuum tube has be5 develop$ to a high degree ( effici5cy & is ! s*eme t is n[ 9 vogue = amateur /ations we %all conf9e our ef=ts "h to expla9+ ! app>atus necess>y & h[ to wire ! v>i\s p>ts toge!r to produce sev]al sizes ( vacuum tube telegraph transmitt]s4 ,s\rces ( ,curr5t = ,telegraph ,transmitt+ ,sets4--,diff]+ f a sp>k-gap transmitt] y _c get any appreciable results ) a l[ voltage batt]y curr5t to />t )4 ,= a purely exp]im5tal vacuum tube telegraph transmitt] y c use en\gh ,b batt]ies to op]ate x b ! curr5t /r5g? ( ^! drops s fact :5 !y are 9 use1 t !y are n at all satisfactory = ! "w4 ,y c1 h[ev]1 use #aaj volt direct curr5t f a light+ circuit z y\r initial s\rce ( p[] to en]gize ! plate ( ! vacuum tube oscillator ( y\r exp]im5tal transmitt]4 ,:]e y h a #aaj volt direct curr5t light+ s]vice 9 y\r home & y want a high] voltage = y\r plate1 y w !n h to use a motor-g5]ator set & ?is co/s money4 ,if y h #aaj volt alt]nat+ curr5t light+ s]vice at h& y\r tr\bles are ov] s f> z co/ is conc]n$ = y c /ep x up to any voltage y want ) a p[] trans=m]4 ,9 ?is *apt] w be %[n h[ to use a direct curr5t = y\r s\rce ( initial p[] & 9 ! next *apt] h[ to use an alt]nat+ curr5t = ! initial p[]4 ,an ,exp]im5tal ,cont9u\s ,wave ,telegraph ,transmitt]4--,y w rememb] t 9 ,*apt] ,,xv we le>n$ h[ ! het]odyne receiv] works & t 9 ! sep>ate het]odyne receiv+ set ! second vacuum tube is us$ solely to set up oscillations4 ,n[ :ile ?is extra tube is us$ z a g5]ator ( oscillations ^! are1 ( c\rse1 v weak & h5ce a detector tube _c be us$ to g5]ate oscillations t are useful = o!r purposes ?an het]odyne receptors & measurem5ts4 ,!re is a vacuum tube amplifi] ,footnote3 ,?is is ! radiation ,,uv-#bja1 made by ! ,radio ,corporation ( ,am]ica1 ,woolwor? ,bldg41 ,new ,york ,city4 made t w /& a plate pot5tial ( #ajj volts1 & ?is c be us$ z a g5]ator ( oscillations by en]giz+ x ) a #aaj volt direct curr5t f y\r light+ s]vice4 ,or 9 a p9* y c use five /&>d ,b batt]ies to develop ! plate voltage1 b ^! w soon run d[n4 ,b :atev] y d1 nev] use a curr5t f a light+ circuit on a tube ( any k9d t has a rat$ plate pot5tial ( less ?an #ajj volts4 ,! ,app>atus ,y ,ne$4--,= ?is exp]im5tal cont9u\s wave telegraph transmitt] get ! foll[+ pieces ( app>atus3 7#a7 "o s+le coil tun] ) ?ree clips2 7#b7 "o 4#jjb mfd4 fix$ cond5s]2 7#c7 ?ree 4#jja mfd4 cond5s]s2 7#d7 "o adju/able grid leak2 7#e7 "o hot-wire ammet]2 7#f7 "o buzz]2 7#g7 "o dry cell2 7#h7 "o telegraph key2 7#i7 "o #ajj volt plate vacuum tube amplifi]2 7#aj7 "o #f volt /orage batt]y2 7#aa7 "o rheo/at2 7#ab7 "o oscillation *oke coil2 7#ac7 "o panel cut-out ) a s+le-?r[1 d\ble-pole swit*1 & a pair ( fuse sockets on x4 ,! ,tun+ ,coil4--,y c ei!r make ?is tun+ coil or buy "o4 ,to make x get two disks ( wood #c_/d-;in* ?ick & #e in*es 9 diamet] & f\r /rips ( h>d wood1 or bett]1 h>d rubb] or composition /rips1 su* z bakelite1 #a_/b-;in* ?ick1 #a in* wide & #e-c_/d in*es long1 & screw !m to ! disks z %[n at ,a 9 ,fig4 #ge4 ,n[ wrap on ?is =m ab\t #be turns ( ,no4 #h or #aj1 ,br[n & ,%>pe gauge1 b>e copp] wire ) a space ( #a_/h-;in* betwe5 ea* turn4 ,get ?ree ( ! smalle/ size t]m9al clips1 see ,b1 & clip !m on to ! diff]5t turns1 :5 y\r tun+ coil is ready = use4 ,y c buy a coil ( ?is k9d = #d4jj or #e4jj4 ,! ,cond5s]s4--,= ! a]ial s]ies cond5s] get "o t has a capacitance ( 4#jjb mfd4 & t w /& a pot5tial ( #c1jjj volts4 ,footnote3 ,! ,u ,c-#ajad ,f>adon cond5s] made by ! ,radio ,corporation ( ,am]ica w s]ve ! purpose4 ,x is %[n at ,c4 ,! o!r ?ree cond5s]s1 see ,d1 are also ( ! fix$ type & may h a capacitance ( 4#jja mfd42 ,footnote3 ,li/ ,no4 #bff2 fix$ receiv+ cond5s]1 sold by ! ,manhattan ,electrical ,supply ,co4 ! block+ cond5s] %\ld pref]ably h a capacitance ( #a_/b a mfd4 ,9 ^! cond5s]s ! leaves ( ! %eet metal are emb$d$ 9 composition4 ,! a]ial cond5s] w co/ y #b4jj & ! o!rs #ge c5ts ea*4 ,illu/ration3 7,a7 ,fig4 #ge4--;,app>atus = ,exp]im5tal ,c4 ,w4 ,telegraph ,transmitt]4 ,illu/ration3 ,fig4 #ge4--;,app>atus = ,exp]im5tal ,c4 ,w4 ,telegraph ,transmitt]4 ,! ,a]ial ,ammet]4--,?is in/rum5t is also call$ a hot-wire ammet] because ! oscillat+ curr5ts fl[+ ?r\gh a piece ( wire heat x accord+ to _! curr5t /r5g? & z ! wire contracts & exp&s x moves a ne$le ov] a scale4 ,! ammet] is connect$ 9 ! a]ial wire sy/em1 ei!r 9 ! a]ial side or ! gr\nd side--! latt] place is usually ! mo/ conv5i5t4 ,:5 y tune ! transmitt] s t ! ammet] %[s ! l>ge/ am\nt ( curr5t surg+ 9 ! a]ial wire sy/em y c consid] t ! oscillation circuits are 9 tune4 ,a hot-wire ammet] read+ to #b4e amp]es w s]ve y\r ne$s1 x co/s #f4jj & is %[n at ,e 9 ,fig4 #ge4 ,illu/ration3 ,unit$ ,/ates ,naval ,high ,p[] ,/ation1 ,arl+ton ,va4 ,g5]al view ( ,p[] ,room4 ,at ! left c be se5 ! ,control ,swit*bo>ds1 & ov]head1 ! great #cj ,k4,w4 ,arc ,transmitt] ) ,accessories4 ,! ,buzz] & ,dry ,cell4--,:ile a het]odyne1 or beat1 receptor c receive cont9u\s wave telegraph signals an ord9>y cry/al or vacuum tube detector receiv+ set _c receive !m unless !y are brok5 up into tra9s ei!r at ! s5d+ /ation or at ! receiv+ /ation1 & x is consid]$ ! bett] practice to d ?is at ! =m] r ?an at ! latt] /ation4 ,= ?is small transmitt] y c use an ord9>y buzz] z %[n at ,f4 ,a dry cell or two mu/ be us$ to en]gize ! buzz]4 ,y c get "o = ab\t #ge c5ts4 ,! ,telegraph ,key4--,any k9d ( a telegraph key w s]ve to break up ! tra9s ( su/a9$ oscillations into dots & da%es4 ,! key %[n at ,g is m\nt$ on a composition base & is ! *eape/ key made1 co/+ #a4ej4 ,! ,vacuum ,tube ,oscillator4--,z expla9$ be=e y c use any amplify+ tube t is made = a plate pot5tial ( #ajj volts4 ,! curr5t requir$ = heat+ ! filam5t is ab\t #a amp]e at #f volts4 ,a porcela9 socket %\ld be us$ = ?is tube z x is ! be/ insulat+ mat]ial = ! purpose4 ,an amplifi] tube ( ?is type is %[n at ,h & co/s #f4ej4 ,! ,/orage ,batt]y4--,a /orage batt]y is us$ to heat ! filam5t ( ! tube1 j z x is ) a detector tube1 & x c be ( any make or capacity z long z x w develop #f volts4 ,! *eape/ #f volt /orage batt]y on ! m>ket has a #bj to #dj amp]e-h\r capacity & sells = #ac4jj4 ,! ,batt]y ,rheo/at4--,z ) ! receptors a rheo/at is ne$$ to regulate ! curr5t t heats ! filam5t4 ,a rheo/at ( ?is k9d is %[n at ,i & is li/$ at #a4be4 ,! ,oscillation ,*oke ,coil4--,?is coil is connect$ 9 betwe5 ! oscillation circuits & ! s\rce ( curr5t :i* fe$s ! oscillator tube to keep ! oscillations set up by ! latt] f surg+ back into ! s]vice wires :]e !y w\ld break d[n ! insulation4 ,y c make an oscillation *oke coil by w9d+ say #ajj turns ( ,no4 #bh ,br[n & ,%>pe gauge d\ble cotton cov]$ magnet wire on a c>dbo>d cyl9d] #b in*es 9 diamet] & #b-a_/b in*es long4 ,transmitt] ,connectors4--,= connect+ up ! diff]5t pieces ( app>atus ( ! transmitt] x is a good s*eme to use copp] braid2 ?is is made ( braid$ copp] wire 9 ?ree sizes & sells = #g1ae & #bj c5ts a foot respectively4 ,a piece ( x is pictur$ at ,j4 ,! ,panel ,cut-,out4--,?is is us$ to connect ! cord ( ! #aaj-volt lamp socket ) ! transmitt]4 ,x consi/s ( a pair ( plug cut\ts & a s+le-?r[1 d\ble-pole swit* m\nt$ on a porcela9 base z %[n at ,k4 ,9 "s localities x is necess>y to place ^! 9 an iron box to con=m to ! requirem5ts ( ! fire und]writ]s4 ,connect+ ,up ! ,transmitt+ ,app>atus4--,! way ! v>i\s pieces ( app>atus are connect$ toge!r is %[n 9 ! wir+ diagram4 ,fig4 #gf4 ,beg9 by connect+ "o po/ ( ! ammet] ) ! wire t leads to ! a]ial & ! o!r po/ ( x to "o end ( ! tun+ coil2 connect clip #a to "o t]m9al ( ! 4#jjb mfd4 #c1jjj volt a]ial cond5s] & ! o!r po/ ( ?is ) ! gr\nd4 ,illu/ration3 ,fig4 #gf--;,exp]im5tal ,c4,w4 ,telegraph ,transmitt] ,n[ connect ! end ( ! tun+ coil t leads to ! ammet] ) "o end ( ! 4#jja mfd4 grid cond5s] & ! o!r end ( ?is ) ! grid ( ! vacuum tube4 ,connect ! telegraph key1 ! buzz] & ! dry cell 9 s]ies & !n %unt !m ar\nd ! grid cond5s]4 ,next connect ! plate ( ! tube ) "o end ( ! 4#jja mfd4 block+ cond5s] & ! o!r end ( ?is ) ! clip #b on ! tun+ coil4 ,connect "o end ( ! filam5t ) ! or positive electrode ( ! /orage batt]y1 ! - or negative electrode ( ?is ) "o po/ ( ! rheo/at & ! o!r po/ ( ! latt] ) ! o!r end ( ! filam5t2 !n connect clip #c ) ! or positive side ( ! /orage batt]y4 ,?is done connect "o end ( ! *oke coil to ! conductor t leads to ! plate & connect ! o!r end ( ! *oke coil to "o ( ! taps ( ! swit* on ! panel cut-out4 ,connect ! or positive electrode ( ! /orage batt]y to ! o!r swit* tap & betwe5 ! swit* & ! *oke coil connect ! protective cond5s] across ! #aaj volt fe$ wires4 ,f9ally connect ! lamp cord f ! socket to ! plug fuse taps :5 y\r exp]im5tal cont9u\s wave telegraph transmitt] is ready to use4 ,a #ajj ,mile ,c4 ,w4 ,telegraph ,transmitt]4--,"h is a cont9u\s wave telegraph transmitt] t w cov] di/ances up to #ajj miles t y c rely on4 ,x is built on exactly ! same l9es z ! exp]im5tal transmitt] j describ$1 b in/ead ( us+ a #ajj volt plate amplifi] z a make%ift g5]ator ( oscillations x employs a vacuum tube made especially = sett+ up oscillations & in/ead ( hav+ a l[ plate voltage x is en]giz$ ) #cej volts4 ,! ,app>atus ,y ,ne$4--,= ?is transmitt] y require3 7#a7 "o oscillation trans=m]2 7#b7 "o hot-wire ammet]2 7#c7 "o a]ial s]ies cond5s]2 7#d7 "o grid leak resi/ance2 7#e7 "o *opp]2 7#f7 "o key circuit *oke coil2 7#g7 "o #e watt vacuum tube oscillator2 7#h7 "o #f volt /orage batt]y2 7#i7 "o batt]y rheo/at2 7#aj7 "o batt]y voltmet]2 7#aa7 "o block+ cond5s]2 7#ab7 "o p[] circuit *oke coil1 & 7#ac7 "o motor-g5]ator4 ,! ,oscillation ,trans=m]4--,! tun+ coil1 or oscillation trans=m] z ?is "o is call$1 is a conductively c\pl$ tun]--t is1 ! prim>y & second>y coils =m "o cont9u\s coil in/ead ( two sep>ate coils4 ,?is tun] is made up ( #be turns ( ?9 copp] /rip1 #c_/h in* wide & ) its edges r\nd$1 & ?is is secur$ to a wood base z %[n at ,a 9 ,fig4 #gg4 ,x is fitt$ ) "o fix$ tap & ?ree clips to ea* ( :i* a l5g? ( copp] braid is atta*$4 ,x has a diamet] ( #f-a_/d in*es1 a height ( #g-g_/h in*es & a l5g? ( #i-c_/h in*es1 & x co/s #aa4jj4 ,illu/ration3 ,fig4 #gg4--;,app>atus ( #ajj ,mile ,c4 ,w4 ,telegraph ,transmitt]4 ,! ,a]ial ,cond5s]4--,?is cond5s] is made up ( ?ree fix$ cond5s]s ( diff]5t capacitances1 namely 4#jjjc1 4#jjjd & 4#jjje mfd41 & ^! are made to /& a pot5tial ( #gejj volts4 ,! cond5s] is !re=e adju/able &1 z y w see f ! picture ,b1 x has "o t]m9al wire at "o end & ?ree t]m9al wires at ! o!r end s t "o1 two or ?ree cond5s]s c be us$ 9 s]ies ) ! a]ial4 ,a cond5s] ( ?is k9d co/s #e4dj4 ,! ,a]ial ,ammet]4--,?is is ! same k9d ( a hot-wire ammet] already describ$ 9 connection ) ! exp]im5tal set1 b x reads to #e amp]es4 ,! ,grid & ,block+ ,cond5s]s4--,ea* ( ^! is a fix$ cond5s] ( 4#jjb mfd4 capacitance & is rat$ to /& #c1jjj volts4 ,x is made l ! a]ial cond5s] b has only two t]m9als4 ,x co/s #b4jj4 ,! ,key ,circuit ,app>atus4--,?is consi/s (3 7#a7 ! grid leak2 7#b7 ! *opp]2 7#c7 ! *oke coil1 & 7#d7 ! key4 ,! grid leak is connect$ 9 ! lead f ! grid to ! a]ial to keep ! voltage on ! grid at ! "r pot5tial4 ,x has a resi/ance ( #ejjj ohms ) a mid-tap at #bejj ohms z %[n at ,c4 ,x co/s #b4jj4 ,! *opp] is simply a rot>y int]rupt] driv5 by a small motor4 ,x comprises a :eel ( insulat+ mat]ial 9 :i* #cj or m metal segm5ts are set 9 an insulat+ disk z %[n at ,d4 ,a metal contact call$ a bru% is fix$ on ei!r side ( ! :eel4 ,x co/s ab\t #g4jj & ! motor to drive x is extra4 ,! *oke coil is w\nd up ( ab\t #bej turns ( ,no4 #cj ,br[n & ,%>pe gauge cotton cov]$ magnet wire on a spool :i* has a diamet] ( #b in*es & a l5g? ( #c-a_/d in*es4 ,! #e ,watt ,oscillator ,vacuum ,tube4--,?is tube is made l ! amplifi] tube describ$ = use ) ! prec$+ exp]im5tal transmitt]1 b x is l>g]1 has a m p]fect vacuum1 & w /& a plate pot5tial ( #cej volts :ile ! plate curr5t is 4#jde amp]e4 ,! filam5t takes a curr5t ( a little m ?an #b amp]es at #g4e volts4 ,a /&>d #d-tap base is us$ ) x4 ,! tube co/s #h4jj & ! porcela9 base is #a4jj extra4 ,x is %[n at ,e4 ,! ,/orage ,batt]y & ,rheo/at4--,?is mu/ be a #e-;cell batt]y s t x w develop #aj volts4 ,a /orage batt]y ( any capacity c be us$ b ! l[e/ pric$ "o co/s ab\t #bb4jj4 ,! rheo/at = regulat+ ! batt]y curr5t is ! same z t us$ 9 ! prec$+ exp]im5tal transmitt]4 ,! ,filam5t ,voltmet]4--,to get ! be/ results x is necess>y t ! voltage ( ! curr5t :i* heats ! filam5t be kept at ! same value all ( ! "t4 ,= ?is transmitt] a direct curr5t voltmet] read+ f #j to #ae volts is us$4 ,x is %[n at ,f & co/s #g4ej4 ,! ,oscillation ,*oke ,coil4--,?is is made exactly l ! "o describ$ 9 connection ) ! exp]im5tal transmitt]4 ,! ,motor-,g5]ator ,set4--,:]e y h only a #aaj or a #bbj volt direct curr5t available z a s\rce ( p[] y ne$ a motor-g5]ator to *ange x to #cej volts1 & ?is is an exp5sive piece ( app>atus4 ,x consi/s ( a s+le armature core ) a motor w9d+ & a g5]ator w9d+ on x & ea* ( ^! has its own commutator4 ,:]e ! l[ voltage curr5t fl[s into "o ( ! w9d+s x drives its z a motor & ?is 9 turn g5]ates ! high] voltage curr5t 9 ! o!r w9d+4 ,get a #ajj watt #cej volt motor-g5]ator2 x is %[n at ,f & co/s ab\t #ge4jj4 ,! ,panel ,cut-,out4--,?is swit* & fuse block is ! same z t us$ 9 ! exp]im5tal set4 ,! ,protective ,cond5s]4--,?is is a fix$ cond5s] hav+ a capacitance ( #a mfd4 & w /& #gej volts4 ,x co/s #b4jj4 ,connect+ ,up ! ,transmitt+ ,app>atus4--,f all t has gone be=e y h se5 t ea* piece ( app>atus is fitt$ ) t]m9al1 wires1 taps or b9d+ po/s4 ,to connect up ! p>ts ( ?is transmitt] x is only necess>y to make ! connections z %[n 9 ! wir+ diagram ,fig4 #gh4 ,illu/ration3 ,fig4 #gh4--e to #ej ,watt ,c4 ,w4 ,telegraph ,transmitt]4 7,) ,s+le ,oscillation ,tube47 ,a #bjj ,mile ,c4 ,w4 ,telegraph ,transmitt]4--,to make a cont9u\s wave telegraph transmitt] t w cov] di/ances up to #bjj miles all y h to d is to use two #e watt vacuum tubes 9 p>allel1 all ( ! re/ ( ! app>atus be+ exactly ! same4 ,connect+ ! oscillator tubes up 9 p>allel means t ! two filam5ts are connect$ across ! leads ( ! /orage batt]y1 ! two grids on ! same lead t goes to ! a]ial & ! two plates on ! same lead t goes to ! positive pole ( ! g5]ator4 ,:]e two or m oscillator tubes are us$ only "o /orage batt]y is ne$$1 b ea* filam5t mu/ h its own rheo/at4 ,! wir+ diagram ,fig4 #gi %[s h[ ! two tubes are connect$ up 9 p>allel4 ,illu/ration3 ,fig4 #gi4--bjj ,mile ,c4,w4 ,telegraph ,transmitt] 7,) ,two ,tubes 9 ,p>allel47 ,a #ejj ,mile ,c4 ,w4 ,telegraph ,transmitt]4--,= s5d+ to di/ances ( ov] #bjj miles & up to #ejj miles y c use ei!r3 7#a7 ?ree or f\r #e watt oscillator tubes 9 p>allel z describ$ above1 or 7#b7 "o #ej watt oscillator tube4 ,mu* ( ! app>atus = a #ej watt tube set is exactly ! same z t us$ = ! #e watt sets4 ,"s ( ! p>ts1 h[ev]1 mu/ be proportionately l>g] ?\gh ! design all ! way ?r\gh rema9s ! same4 ,! ,app>atus & ,connections4--,! a]ial s]ies cond5s]1 ! block+ cond5s]1 ! grid cond5s]1 ! telegraph key1 ! *opp]1 ! *oke coil 9 ! key circuit1 ! filam5t voltmet] & ! protective cond5s] 9 ! p[] circuit are id5tical ) ^? describ$ = ! #e watt transmitt+ set4 ,! #ej ,watt ,vacuum ,tube ,oscillator4--,?is is ! size ( tube g5]ally us$ by amateurs = long di/ance cont9u\s wave telegraphy4 ,a s+le tube w develop #b to #c amp]es 9 y\r a]ial4 ,! filam5t takes a #aj volt curr5t & a plate pot5tial ( #a1jjj volts is ne$$4 ,"o ( ^! tubes is %[n 9 ,fig4 #hj & ! co/ is #cj4jj4 ,a tube socket to fit x co/s #b4ej extra4 ,illu/ration3 ,fig4 #hj4--ej ,watt ,oscillator ,vacuum ,tube4 ,! ,a]ial ,ammet]4--,?is %\ld read to #e amp]es & ! co/ is #f4be4 ,! ,grid ,leak ,resi/ance4--,x has ! same resi/ance1 namely #e1jjj ohms z ! "o us$ ) ! #e watt tube transmitt]1 b x is a little l>g]4 ,x is li/$ at #a4fe4 ,! ,oscillation ,*oke ,coil4--,! *oke coil 9 ! p[] circuit is made ( ab\t #bfj turns ( ,no4 #cj ,b4 ,s4 cotton cov]$ magnet wire w\nd on a spool #b-a_/d in*es 9 diamet] & #c-a_/d in*es long4 ,! ,filam5t ,rheo/at4--,?is is made to take c>e ( a #aj volt curr5t & x co/s #aj4jj4 ,! ,filam5t ,/orage ,batt]y4--,?is mu/ develop #ab volts & "o hav+ an output ( #dj amp]e-h\rs co/s ab\t #be4jj4 ,! ,protective ,cond5s]4--,?is cond5s] has a capacitance ( #a mfd4 & co/s #b4jj4 ,! ,motor-,g5]ator4--,:]e y use "o #ej watt oscillator tube y w ne$ a motor-g5]ator t develops a plate pot5tial ( #ajjj volts & has an output ( #bjj watts4 ,?is ma*9e w /& y ab\t #ajj4jj4 ,! diff]5t pieces ( app>atus = ?is set are connect$ up exactly ! same z %[n 9 ! wir+ diagram 9 ,fig4 #gh4 ,a #ajjj ,mile ,c4 ,w4 ,telegraph ,transmitt]4--,all ( ! p>ts ( ?is transmitt+ set are ! same z = ! #ejj mile transmitt] j describ$ except ! motor g5]ator & :ile ?is develops ! same plate pot5tial1 i4e41 #a1jjj volts1 x mu/ h an output ( #ejj watts2 x w co/ y 9 ! neighborhood ( #age4jj4 ,= ?is long di/ance transmitt] y use two #ej watt oscillator tubes 9 p>allel & all ( ! p>ts are connect$ toge!r exactly ! same z = ! #bjj mile transmitt] %[n 9 ! wir+ diagram 9 ,fig4 #gi4 ,,*apt] ,,xvii ,,cont9u\s ,,wave ,,telegraph ,,transmitt+ ,,sets ,,) ,,alt]nat+ ,,curr5t ,)9 ! la/ few ye>s alt]nat+ curr5t has l>gely tak5 ! place ( direct curr5t = light1 heat & p[] purposes 9 & ar\nd t[ns & cities & if y h alt]nat+ curr5t s]vice 9 y\r home y c in/all a long di/ance cont9u\s wave telegraph transmitt] ) v little tr\ble & at a comp>atively small exp5se4 ,a #ajj ,mile ,c4 ,w4 ,telegraph ,transmitt+ ,set4--,! pr9cipal pieces ( app>atus = ?is transmitt] are ! same z ^? us$ = ! #ajj ,mile ,cont9u\s ,wave ,telegraph ,transmitt+ ,set describ$ & pictur$ 9 ! prec$+ *apt] :i* us$ direct curr5t1 except t an alt]nat+ curr5t p[] trans=m] is employ$ in/ead ( ! m co/ly motor-g5]ator4 ,! ,app>atus ,requir$4--,! v>i\s pieces ( app>atus y w ne$ = ?is transmitt+ set are3 7#a7 "o hot-wire ammet] = ! a]ial z %[n at ,e 9 ,fig4 #ge1 b :i* reads to #e amp]es in/ead ( to #b4e amp]es2 7#b7 "o tun+ coil z %[n at ,a 9 ,fig4 #gg2 7#c7 "o a]ial cond5s] z %[n at ,b 9 ,fig4 #gg2 7#d7 "o grid leak z %[n at ,c 9 ,fig4 #gg2 7#e7 "o telegraph key z %[n at ,g 9 ,fig4 #ge2 7#f7 "o grid cond5s]1 made l ! a]ial cond5s] b hav+ only two t]m9als2 7#g7 "o #e watt oscillator tube z %[n at ,e 9 ,fig4 #gg2 7#h7 "o 4#jjb mfd4 #c1jjj volt by-pass cond5s]1 made l ! a]ial & grid cond5s]s2 7#i7 "o pair ( *oke coils = ! high voltage second>y circuit2 7#aj7 "o milli-ammet]2 7#aa7 "o ,a4 ,c4 p[] trans=m]2 7#ab7 "o rheo/at z %[n at ,i 9 ,fig4 #ge1 & 7#ac7 "o panel cut-out z %[n at ,k 9 ,fig4 #ge4 ,! ,*oke ,coils4--,ea* ( ^! is made by w9d+ ab\t #ajj turns ( ,no4 #bh1 ,br[n & ,%>pe gauge1 cotton cov]$ magnet wire on a spool #b in*es 9 diamet] & #b-a_/b in*es long1 :5 x w h an inductance ( ab\t #j4e millih5ry ,footnote3 ,a millih5ry is #a_/ajjj? "p ( a h5ry4 at #a1jjj cycles4 ,! ,milli-ammet]4--,?is is an alt]nat+ curr5t ammet] & reads f #j to #bej milliamp]es2 ,footnote3 ,a milliamp]e is ! #a_/ajjj? "p ( an amp]e4 & is us$ = measur+ ! second>y curr5t t en]gizes ! plate ( ! oscillator tube4 ,x looks l ! a]ial ammet] & co/s ab\t #g4ej4 ,! ,a4 ,c4 ,p[] ,trans=m]4--,diff]+ f ! motor g5]ator set ! p[] trans=m] has no mov+ p>ts4 ,= ?is transmitt+ set y ne$ a trans=m] t has an input ( #cbe volts4 ,x is made to "w on a #ej to #fj cycle curr5t at #ajb4e to #aae volts1 :i* is ! range ( voltage ( ! ord9>y alt]nat+ light+ curr5t4 ,?is adju/m5t = voltage is made by means ( taps br\ght out f ! prim>y coil to a rot>y swit*4 ,! high voltage second>y coil :i* en]gizes ! plate has an output ( #age watts & develops a pot5tial ( f #cej to #a1ajj volts4 ,! l[ voltage second>y coil :i* heats ! filam5t has an output ( #age watts & develops #g4e volts4 ,?is trans=m]1 :i* is %[n 9 ,fig4 #ha1 is l>ge en\gh to take c>e ( f "o to f\r #e watt oscillator tubes4 ,x weighs ab\t #ae p\nds & sells = #be4jj4 ,illu/ration3 ,fig4 #ha4--;,alt]nation ,curr5t ,p[] ,trans=m]4 7,= ,c4 ,w4 ,telegraphy & ,wireless ,telephony47 ,illu/ration3 ,! ,trans=m] & ,tun] ( ! ,_w's ,l>ge/ ,radio ,/ation4 ,own$ by ! ,radio ,corporation ( ,am]ica at ,rocky ,po9t ne> ,port ,jeff]son ,l4,i4 ,connect+ ,up ! ,app>atus4--,! wir+ diagram ,fig4 #hb %[s cle>ly h[ all ( ! connections are made4 ,x w be obs]v$ t a /orage batt]y is n ne$$ z ! second>y coil ( ! trans=m] supplies ! curr5t to heat ! filam5t ( ! oscillator4 ,! filam5t voltmet] is connect$ across ! filam5t second>y coil t]m9als1 :ile ! plate milli-ammet] is connect$ to ! mid-taps ( ! plate second>y coil & ! filam5t second>y coil4 ,illu/ration3 ,fig4 #hb4 ,wir+ ,diagram = #bjj to #ejj ,mile ,c4,w4 ,telegraph ,transmitt+ ,set4 7,) ,alt]nat+ ,curr5t7 ,a #bjj to #ejj ,mile ,c4 ,w4 ,telegraph ,transmitt+ ,set4--,di/ances ( f #bjj to #ejj miles c be successfully cov]$ ) a telegraph transmitt] us+ two1 ?ree or f\r #e watt oscillator tubes 9 p>allel4 ,! app>atus ne$$ is id5tical ) t us$ = ! #ajj mile transmitt] j describ$4 ,! tubes are connect$ 9 p>allel z %[n 9 ! wir+ diagram 9 ,fig4 #hc4 ,illu/ration3 ,fig4 #hc4--,wir+ ,diagram = #ejj to #ajjj ,mile ,c4 ,w4 ,telegraph ,transmitt]4 ,a #ejj to #a1jjj ,mile ,c4 ,w4 ,telegraph ,transmitt+ ,set4--,) ! app>atus describ$ = ! above set & a s+le #ej watt oscillator tube a di/ance ( upw>ds ( #ejj miles c be cov]$1 :ile ) two #ej watt oscillator tubes 9 p>allel y c cov] a di/ance ( #a1jjj miles )\t difficulty1 & ne>ly #b1jjj miles h be5 cov]$ ) ?is set4 ,! ,app>atus ,requir$4--,all ( ! app>atus = ?is ,c4 ,w4 telegraph transmitt+ set is ! same z t describ$ = ! #ajj & #bjj mile sets b y w ne$3 7#a7 "o or two #ej watt oscillator tubes ) sockets2 7#b7 "o key cond5s] t has a capacitance ( #a mfd41 & a rat$ pot5tial ( #a1gej volts2 7#c7 "o #j to #ejj milli-ammet]2 7#d7 "o a]ial ammet] read+ to #e amp]es1 & 7#e7 an ,a4 ,c4 p[] trans=m] = "o or two #ej watt tubes4 ,illu/ration3 ,broadca/+ ,gov]nm5t ,reports by ,wireless f ,wa%+ton4 ,?is %[s ,mr4 ,gale at "w ) 8 set 9 ! ,po/ ,(fice ,dep>tm5t4 ,! ,alt]nat+ ,curr5t ,p[] ,trans=m]4--,?is p[] trans=m] is made exactly l ! "o describ$ 9 connection ) ! prec$+ #ajj mile transmitt] & pictur$ 9 ,fig4 #ha1 b x is consid]ably l>g]4 ,l ! small] "o1 h[ev]1 x is made to "w ) a #ej to #fj cycle curr5t at #ajb4e to #aae volts &1 h5ce1 c be us$ ) any ,a4 ,c4 light+ curr5t4 ,x has an input ( #gej volts & ! high voltage second>y coil :i* en]gizes ! plate has an output ( #dej watts & develops #a1ejj to #c1jjj volts4 ,! l[ voltage second>y coil :i* heats ! filam5t develops #aj4e volts4 ,?is trans=m] w supply curr5t = "o or two #ej-watt oscillator tubes & x co/s ab\t #dj4jj4 ,connect+ ,up ! ,app>atus4--,:]e a s+le oscillator tube is us$ ! p>ts are connect$ z %[n 9 ,fig4 #hb1 & :]e two tubes are connect$ 9 p>allel ! v>i\s pieces ( app>atus are wir$ toge!r z %[n 9 ,fig4 #hc4 ,! only diff]5ce betwe5 ! #e watt tube transmitt] & ! #ej watt tube transmitt] is 9 ! size ( ! app>atus ) "o exception2 :]e "o or two #ej watt tubes are us$ a second cond5s] ( l>ge capacitance 7#a mfd47 is plac$ 9 ! grid circuit & ! telegraph key is %unt$ ar\nd x z %[n 9 ! diagram ,fig4 #hc4 ,,*apt] ,,xviii ,,wireless ,,telephone ,,transmitt+ ,,sets ,,) ,,direct ,,& ,,alt]nat+ ,,curr5ts ,9 "t pa/ ! mo/ difficult ( all electrical app>atus = ! amateur to make1 in/all & "w 0 ! wireless telephone4 ,?is 0 because x requir$ a direct curr5t ( n less ?an #ejj volts to set up ! su/a9$ oscillations & all ord9>y direct curr5t = light+ purposes is usually g5]at$ at a pot5tial ( #aaj volts4 ,n[ z y "k x is easy to /ep-up a #aaj volt alt]nat+ curr5t to any voltage y wi% ) a p[] trans=m] b until )9 comp>atively rec5t ye>s an alt]nat+ curr5t c\ld n be us$ = ! production ( su/a9$ oscillations = ! v good reason t ! /ate ( ! art _h n advanc$ t f>4 ,9 ! new ord] ( ?+s ^! difficulties h all b vani%$ & :ile a wireless telephone transmitt] /ill requires a high voltage direct curr5t to op]ate x ?is is easily obta9$ f #aaj volt s\rce ( alt]nat+ curr5t by means ( vacuum tube rectifi]s4 ,! pulsat+ direct curr5ts are !n pass$ ?r\gh a filt]+ reactance coil1 call$ a reactor1 & "o or m cond5s]s1 & ^! smoo? !m out until !y approximate a cont9u\s direct curr5t4 ,! latt] is !n made to fl[ ?r\gh a vacuum tube oscillator :5 x is conv]t$ into high frequ5cy oscillations & ^! are v>i$1 or modulat$1 z x is call$1 by a microphone transmitt] su* z is us$ = ord9>y wire telephony4 ,! en]gy ( ^! su/a9$ modulat$ oscillations is !n radiat$ into space f ! a]ial 9 ! =m ( electric waves4 ,! di/ance t c be cov]$ ) a wireless telephone transmitt] is ab\t "o-f\r? z great z t ( a wireless telegraph transmitt] hav+ ! same input ( initial curr5t1 b x is long en\gh to satisfy ! mo/ en?usia/ic amateur4 ,= in/ance ) a wireless telephone transmitt] :]e an amplifi] tube is us$ to set up ! oscillations & :i* is made = a plate pot5tial ( #ajj volts1 di/ances up to #aj or #ae miles c be cov]$4 ,) a s+le #e watt oscillator tube en]giz$ by a direct curr5t ( #cej volts f ei!r a motor-g5]ator or f a p[] trans=m] 7aft] x has be5 rectifi$ & smoo!d out7 spee* & music c be transmitt$ to upw>ds ( #be miles4 ,:]e two #e watt tubes connect$ 9 p>allel are us$ wireless telephone messages c be transmitt$ to di/ances ( #dj or #ej miles4 ,fur!r1 a s+le #ej watt oscillator tube w s5d to di/ances ( #ej to #ajj miles :ile two ( ^! tubes 9 p>allel w s5d f #ajj to #bjj miles4 ,f9ally1 :]e f\r or five oscillator tubes are connect$ 9 p>allel proportionately great] di/ances c be cov]$4 ,a ,%ort ,di/ance ,wireless ,telephone ,transmitt+ ,set-,) #aaj ,volt ,direct ,light+ ,curr5t4--,= ?is v simple1 %ort di/ance wireless telephone transmitt+ set y ne$ ! same app>atus z t describ$ & pictur$ 9 ! beg9n+ ( ,*apt] ,,xvi = a ,%ort ,di/ance ,c4 ,w4 ,telegraph ,transmitt]1 except t y use a microphone transmitt] in/ead ( a telegraph key4 ,if y h a #aaj volt direct light+ curr5t 9 y\r home y c put up ?is %ort di/ance set = v little money & x w be well wor? y\r :ile to d s4 ,! ,app>atus ,y ,ne$4--,= ?is set y require3 7#a7 "o tun+ coil z %[n at ,a & ,b 9 ,fig4 #ge2 7#b7 "o a]ial ammet] z %[n at ,c 9 ,fig4 #ge2 7#c7 "o a]ial cond5s] z %[n at ,c 9 ,fig4 #ge2 7#d7 "o grid1 block+ & protective cond5s] z %[n at ,d 9 ,fig4 #ge2 7#e7 "o grid leak z %[n at ,c 9 ,fig4 #gg2 7#f7 "o vacuum tube amplifi] :i* is us$ z an oscillator2 7#g7 "o #f volt /orage batt]y2 7#h7 "o rheo/at z %[n at ,i 9 ,fig4 #ge2 7#i7 "o oscillation *oke coil2 7#aj7 "o panel cut-out z %[n at ,k 9 ,fig4 #ge & an ord9>y microphone transmitt]4 ,! ,microphone ,transmitt]4--,! be/ k9d ( a microphone to use ) ?is & o!r telephone transmitt+ sets is a ,we/]n ,electric ,no4 #bhd-,w4 ,footnote3 ,made by ! ,we/]n ,electric ,company1 ,*icago1 ,ill4 ,?is is kn[n z a solid back transmitt] & is ! /&>d comm]cial type us$ on all long di/ance ,bell telephone l9es4 ,x articulates %>ply & di/9ctly & !re are no curr5t v>iations to di/ort ! wave =m ( ! voice & x w n buzz or sizzle4 ,x is %[n 9 ,fig4 #hd & co/s #b4jj4 ,any o!r good microphone transmitt] c be us$ if desir$4 ,illu/ration3 ,fig4 #hd4--,/&>d ,microphone ,transmitt]4 ,connect+ ,up ! ,app>atus4--,beg9 by connect+ ! lead+-9 wire ) "o ( ! t]m9als ( ! microphone transmitt]1 z %[n 9 ! wir+ diagram ,fig4 #he1 & ! o!r t]m9al ( ?is to "o end ( ! tun+ coil4 ,n[ connect clip #a ( ! tun+ coil to "o ( ! po/s ( ! hot-wire ammet]1 ! o!r po/ ( ?is to "o end ( a]ial cond5s] &1 f9ally1 ! o!r end ( ! latt] ) ! wat] pipe or o!r gr\nd4 ,! microphone c be connect$ 9 ! gr\nd wire & ! ammet] 9 ! a]ial wire & ! results w be practically ! same4 ,illu/ration3 ,fig4 #he4--,wir+ ,diagram ( ,%ort ,di/ance ,wireless ,telephone ,set4 7,microphone 9 ,a]ial ,wire47 ,next connect "o end ( ! grid cond5s] to ! po/ ( ! tun+ coil t makes connection ) ! microphone & ! o!r end to ! grid ( ! tube1 & !n %unt ! grid leak ar\nd ! cond5s]4 ,connect ! or positive electrode ( ! /orage batt]y ) "o t]m9al ( ! filam5t ( ! vacuum tube1 ! o!r t]m9al ( ! filam5t ) "o po/ ( ! rheo/at & ! o!r po/ ( ?is ) ! - or negative electrode ( ! batt]y4 ,?is done1 connect clip #b ( ! tun+ coil to ! or positive electrode ( ! batt]y & br+ a lead f x to "o ( ! swit* taps ( ! panel cut-out4 ,n[ connect clip #c ( ! tun+ coil ) "o end ( ! block+ cond5s]1 ! o!r end ( ?is ) "o t]m9al ( ! *oke coil & ! o!r t]m9al ( ! latt] ) ! o!r swit* tap ( ! cut-out4 ,connect ! protective cond5s] across ! direct curr5t fe$ wires betwe5 ! panel cut-out & ! *oke coil4 ,f9ally connect ! ends ( a lamp cord to ! fuse socket taps ( ! cut-out1 & connect ! o!r ends to a lamp plug & screw x into ! lamp socket ( ! fe$ wires4 ,screw 9 a pair ( #e amp]e fuse plugs1 close ! swit* & y are ready to tune ! transmitt] & talk to y\r fri5ds4 ,a #be to #ej ,mile ,wireless ,telephone ,transmitt]--,) ,direct ,curr5t ,motor ,g5]ator4--,:]e y h to />t ) #aaj or #bbj volt direct curr5t & y want to transmit to a di/ance ( #be miles or m y w h to in/all a motor-g5]ator4 ,to make ?is transmitt] y w ne$ exactly ! same app>atus z t describ$ & pictur$ = ! #ajj ,mile ,c4 ,w4 ,telegraph ,transmitt+ ,set 9 ,*apt] ,,xvi1 except t y mu/ sub/itute a microphone transmitt] & a telephone induction coil1 or a microphone trans=m]1 or /ill bett]1 a magnetic modulator1 = ! telegraph key & *opp]4 ,! ,app>atus ,y ,ne$4--,to reit]ate2 ! pieces ( app>atus y ne$ are3 7#a7 "o a]ial ammet] z %[n at ,e 9 ,fig4 #ge2 7#b7 "o tun+ coil z %[n at ,a 9 ,fig4 #gg2 7#c7 "o a]ial cond5s] z %[n at ,b 9 ,fig4 #gg2 7#d7 "o grid leak z %[n at ,c 9 ,fig4 #gg2 7#e7 "o grid1 block+ & protective cond5s]2 7#f7 "o #e watt oscillator tube z %[n at ,e 9 ,fig4 #gg2 7#g7 "o rheo/at z %[n at ,i 9 ,fig4 #ge2 7#h7 "o #aj volt 7#e cell7 /orage batt]y2 7#i7 "o *oke coil2 7#aj7 "o panel cut-out z %[n at ,k 9 ,fig4 #ge1 & 7#aa7 a motor-g5]ator hav+ an input ( #aaj or #bbj volts & an output ( #cej volts4 ,9 addition to ! above app>atus y w ne$3 7#ab7 a microphone transmitt] z %[n 9 ,fig4 #hd2 7#ac7 a batt]y ( f\r dry cells or a #f volt /orage batt]y1 & ei!r 7#ad7 a telephone induction coil z %[n 9 ,fig4 #hf2 7#ae7 a microphone trans=m] z %[n 9 ,fig4 #hg2 or a magnetic modulator z %[n 9 ,fig4 #hh4 ,all ( ^! p>ts h be5 describ$1 z said above1 9 ,*apt] ,,xvi1 except ! microphone modulators4 ,illu/ration3 ,fig4 #hf4--,telephone ,induction ,coil4 7,us$ ) ,microphone ,transmitt]47 ,illu/ration3 ,fig4 #hg4--,microphone ,trans=m]4 7,us$ ) ,microphone ,transmitt]47 ,illu/ration3 ,fig4 #hh4--,magnetic ,modulator4 7,us$ ) ,microphone ,transmitt]47 ,! ,telephone ,induction ,coil4--,?is is a little induction coil t trans=ms ! #f-volt batt]y curr5t aft] x has fl[$ ?r\gh & be5 modulat$ by ! microphone transmitt] into alt]nat+ curr5ts t h a pot5tial ( #a1jjj volts ( m4 ,x consi/s ( a prim>y coil ( ,no4 #bj ,b4 & ,s4 gauge cotton cov]$ magnet wire w\nd on a core ( s(t iron wires :ile ar\nd ! prim>y coil is w\nd a second>y coil ( ,no4 #cj magnet wire4 ,get a /&>d telephone induction coil t has a resi/ance ( #ejj or #gej ohms & ?is w co/ y a c\ple ( doll>s4 ,! ,microphone ,trans=m]4--,?is device is built on exactly ! same pr9ciple z ! telephone induction coil j describ$ b x is m effective because x is design$ especially = modulat+ ! oscillations set up by vacuum tube transmitt]s4 ,z ) ! telephone induction coil1 ! microphone transmitt] is connect$ 9 s]ies ) ! prim>y coil & a #f volt dry or /orage batt]y4 ,9 ! bett] makes ( microphone trans=m]1 !re is a ?ird w9d+1 call$ a side tone coil1 to :i* a headphone c be connect$ s t ! op]ator :o is speak+ into ! microphone c li/5-9 & s le>n if 8 transmitt] is work+ up to /&>d4 ,! ,magnetic ,modulator4--,?is is a small clos$ iron core trans=m] ( peculi> design & hav+ a prim>y & a second>y coil w\nd on x4 ,?is device is us$ to control ! v>iations ( ! oscillat+ curr5ts t are set up by ! oscillator tube4 ,x is made 9 ?ree sizes & = ! transmitt] "h describ$ y want ! smalle/ size1 :i* has an output ( #a_/b to #a-a_/b amp]es4 ,x co/s ab\t #aj4jj4 ,h[ ! ,app>atus ,is ,connect$ ,up4--,! diff]5t pieces ( app>atus are connect$ toge!r 9 exactly ! same way z ! #ajj ,mile ,c4 ,w4 ,telegraph ,set 9 ,*apt] ,,xvi except t ! microphone transmitt] & microphone modulator 7:i*ev] k9d y use7 is sub/itut$ = ! telegraph key & *opp]4 ,n[ !re are ?ree diff]5t ways t ! microphone & its modulator c be connect$ 9 circuit4 ,two ( ! be/ ways are %[n at ,a & ,b 9 ,fig4 #hi4 ,9 ! fir/ way ! second>y t]m9als ( ! modulator are %unt$ ar\nd ! grid leak 9 ! grid circuit z at ,a1 & 9 ! second ! second>y t]m9als are connect$ 9 ! a]ial z at ,b4 ,:]e an induction coil or a microphone trans=m] is us$ !y are %unt$ ar\nd a cond5s]1 b ?is is n necess>y ) ! magnetic modulator4 ,:]e a second tube is us$ z 9 ,fig4 #ij !n ! microphone & its modulator are connect$ ) ! grid circuit & clip #c ( ! tun+ coil4 ,illu/ration3 ,fig4 #hi4--,wir+ ,diagram ( #be to #ej ,mile ,wireless ,telephone4 7,microphone ,modulator ,%unt$ ,ar\nd ,grid-,leak ,cond5s]47 ,illu/ration3 7,b7 ,fig4 #hi4--,microphone ,modulator ,connect$ 9 ,a]ial ,wire4 ,illu/ration3 ,fig4 #ij4--,wir+ ,diagram ( #ej to #ajj ,mile ,wireless ,telephone ,transmitt+ ,set4 ,a #ej to #ajj ,mile ,wireless ,telephone ,transmitt]--,) ,direct ,curr5t ,motor ,g5]ator4--,z ! initial s\rce ( curr5t available is tak5 to be a #aaj or #bbj volt direct curr5t a motor-g5]ator hav+ an output ( #cej volts mu/ be us$ z be=e4 ,! only diff]5ce betwe5 ?is transmitt] & ! prec$+ "o is t3 7#a7 two #e watt tubes are us$1 ! fir/ s]v+ z an oscillator & ! second z a modulator2 7#b7 an oscillation *oke coil is us$ 9 ! plate circuit2 7#c7 a reactance coil or reactor1 is us$ 9 ! plate circuit2 & 7#d7 a reactor is us$ 9 ! grid circuit4 ,! ,oscillation ,*oke ,coil4--,y c make ?is *oke coil by w9d+ ab\t #bge turns ( ,no4 #bh ,b4 & ,s4 gauge cotton cov]$ magnet wire on a spool #b in*es 9 diamet] & #d in*es long4 ,give x a good coat ( %ellac v>ni% & let x dry ?or\ghly4 ,! ,plate & ,grid ,circuit ,reactance ,coils4--,:]e a s+le tube is us$ z an oscillator & a second tube is employ$ z a modulator1 a reactor1 :i* is a coil ( wire w\nd on an iron core1 is us$ 9 ! plate circuit to keep ! high voltage direct curr5t ( ! motor-g5]ator ! same at all times4 ,likewise ! grid circuit reactor is us$ to keep ! voltage ( ! grid at a con/ant value4 ,^! reactors are made alike & a picture ( "o ( !m is %[n 9 ,fig4 #ia & ea* "o w co/ y #e4ge4 ,illu/ration3 ,fig4 #ia4--,plate & ,grid ,circuit ,reactor4 ,connect+ up ! ,app>atus4--,all ( ! diff]5t pieces ( app>atus are connect$ up z %[n 9 ,fig4 #hi4 ,"o ( ! ends ( ! second>y ( ! induction coil1 or ! microphone trans=m]1 or ! magnetic modulator is connect$ to ! grid circuit & ! o!r end to clip #c ( ! tun+ coil4 ,a #ajj to #bjj ,mile ,wireless ,telephone ,transmitt]--,) ,direct ,curr5t ,motor ,g5]ator4--,by us+ ! same connections %[n 9 ! wir+ diagrams 9 ,fig4 #hi & a s+le #ej watt oscillator tube y\r transmitt] w !n h a range ( #ajj miles or s1 :ile if y connect up ! app>atus z %[n 9 ,fig4 #ij & use two #ej watt tubes y c "w up to #bjj miles4 ,mu* ( ! app>atus = a #ej watt oscillator set :]e ei!r "o or two tubes are us$ is ( ! same size & design z t j describ$ = ! #e watt oscillator sets1 b1 z 9 ! ,c4 ,w4 telegraph sets1 "s ( ! p>ts mu/ be proportionately l>g]4 ,! requir$ p>ts are 7#a7 ! #ej watt tube2 7#b7 ! grid leak resi/ance2 7#c7 ! filam5t rheo/at2 7#d7 ! filam5t /orage batt]y2 & 7#e7 ! magnetic modulator4 ,all ( ^! p>ts1 except ! latt]1 are describ$ 9 detail "u ! head+ ( a #ejj ,mile ,c4 ,w4 ,telegraph ,transmitt+ ,set 9 ,*apt] ,,xvi1 & are also pictur$ 9 t *apt]4 ,x is n advisable to use an induction coil = ! modulator = ?is set1 b use1 in/ead1 ei!r a telephone trans=m]1 or bett]1 a magnetic modulator ( ! second size :i* has an output ( f #a-a_/b to #c-a_/b amp]es4 ,! magnetic modulator is describ$ & pictur$ 9 ?is *apt]4 ,a #ej to #ajj ,mile ,wireless ,telephone ,transmitt+ ,set--,) #aaj ,volt ,alt]nat+ ,curr5t4--,if y h a #aaj volt ,footnote3 ,alt]nat+ curr5t = light+ purposes ranges f #ajb4e volts to #aae volts1 s we take ! m$ian & call x #aaj volts4 alt]nat+ curr5t available y c use x = ! initial s\rce ( en]gy = y\r wireless telephone transmitt]4 ,! *ief diff]5ce betwe5 a wireless telephone transmitt+ set t uses an alt]nat+ curr5t & "o t uses a direct curr5t is t3 7#a7 a p[] trans=m] is us$ = /epp+ up ! voltage in/ead ( a motor-g5]ator1 & 7#b7 a vacuum tube rectifi] mu/ be us$ to conv]t ! alt]nat+ curr5t into direct curr5t4 ,! ,app>atus ,y ,ne$4--,= ?is telephone transmitt+ set y ne$3 7#a7 "o a]ial ammet]2 7#b7 "o tun+ coil2 7#c7 "o telephone modulator2 7#d7 "o a]ial s]ies cond5s]2 7#e7 "o #d cell dry batt]y or a #f volt /orage batt]y2 7#f7 "o microphone transmitt]2 7#g7 "o batt]y swit*2 7#h7 "o grid cond5s]2 7#i7 "o grid leak2 7#aj7 two #e watt oscillator tubes ) sockets2 7#aa7 "o block+ cond5s]2 7#ab7 "o oscillation *oke coil2 7#ac7 two filt] cond5s]s2 7#ad7 "o filt] reactance coil2 7#ae7 an alt]nat+ curr5t p[] trans=m]1 & 7#af7 two #bj watt rectifi] vacuum tubes4 ,all ( ! above pieces ( app>atus are ! same z ^? describ$ = ! #ajj ,mile ,c4 ,w4 ,telegraph ,transmitt] 9 ,*apt] ,,xvii1 except3 7a7 ! microphone modulator2 7b7 ! microphone transmitt] & 7c7 ! dry or /orage batt]y1 all ( :i* are describ$ 9 ?is *apt]2 & ! new p>ts :i* are3 7d7 ! rectifi] vacuum tubes2 7e7 ! filt] cond5s]s2 & 7f7 ! filt] reactance coil2 fur!r & f9ally1 ! p[] trans=m] has a ?ird second>y coil on x & x is ?is t fe$s ! alt]nat+ curr5t to ! rectifi] tubes1 :i* 9 turn conv]ts x into a pulsat+ direct curr5t4 ,! ,vacuum ,tube ,rectifi]4--,?is rectifi] has two electrodes1 t is1 x has a filam5t & a plate l ! orig9al vacuum tube detector1 ,! smalle/ size rectifi] tube requires a plate pot5tial ( #eej volts :i* is develop$ by "o ( ! second>y coils ( ! p[] trans=m]4 ,! filam5t t]m9al takes a curr5t ( #g4e volts & ?is is suppli$ by ano!r second>y coil ( ! trans=m]4 ,?is rectifi] tube deliv]s a direct curr5t ( #bj watts at #cej volts4 ,x looks exactly l ! #e watt oscillator tube :i* is pictur$ at ,e 9 ,fig4 #gg4 ,! price is #g4ej4 ,! ,filt] ,cond5s]s4--,^! cond5s]s are us$ 9 connection ) ! reactance coil to smoo? out ! pulsat+ direct curr5t aft] x has pass$ ?r\gh ! rectifi] tube4 ,!y h a capacitance ( #a mfd4 & w /& #gej volts4 ,^! cond5s]s co/ ab\t #b4jj ea*4 ,! ,filt] ,reactance ,coil4--,?is reactor :i* is %[n 9 ,fig4 #ib1 has ab\t ! same appe>ance z ! p[] trans=m] b x is some:at small]4 ,x consi/s ( a coil ( wire w\nd on a s(t iron core & has a l>ge inductance1 h5ce ! capacitance ( ! filt] cond5s]s are proportionately small] ?an :]e a small inductance is us$ :i* has be5 ! g5]al practice4 ,! size y require = ?is set has an output ( #afj milliamp]es & x w supply curr5t = "o to f\r #e watt oscillator tubes4 ,?is size ( reactor co/s #aa4ej4 ,illu/ration3 ,fig4 #ib4--;,filt] ,reactor = ,smoo?+ out ,rectifi$ ,curr5ts4 ,connect+ ,up ! ,app>atus4--,! wir+ diagram 9 ,fig4 #ic %[s h[ ! v>i\s pieces ( app>atus = ?is telephone transmitt] are connect$ up4 ,y w obs]ve3 7#a7 t ! t]m9als ( ! p[] trans=m] second>y coil :i* develops #aj volts are connect$ to ! filam5ts ( ! oscillator tubes2 7#b7 t ! t]m9als ( ! o!r second>y coil :i* develops #aj volts are connect$ ) ! filam5ts ( ! rectifi] tubes2 7#c7 t ! t]m9als ( ! ?ird second>y coil :i* develops #eej volts are connect$ ) ! plates ( ! rectifi] tubes2 7#d7 t ! pair ( filt] cond5s]s are connect$ 9 p>allel & ^! are connect$ to ! mid-taps ( ! two filam5t second>y coils2 7#e7 t ! reactance coil & ! ?ird filt] cond5s] are connect$ toge!r 9 s]ies & ^! are %unt$ across ! filt] cond5s]s1 :i* are 9 p>allel2 &1 f9ally1 7#f7 a lead connects ! mid-tap ( ! #eej-volt second>y coil ( ! p[] trans=m] ) ! connection betwe5 ! reactor & ! ?ird filt] cond5s]4 ,illu/ration3 ,fig #ic4--ajj to #bjj ,mile ,wireless ,telephone ,transmitt]4 ,a #ajj to #bjj ,mile ,wireless ,telephone ,transmitt+ ,set--,) #aaj ,volt ,alt]nat+ ,curr5t4--,?is telephone transmitt] is built up ( exactly ! same pieces ( app>atus & connect$ up 9 precisely ! same way z ! "o j describ$ & %[n 9 ,fig4 #ic4 ,app>atus ,requir$4--,! only diff]5ces betwe5 ?is & ! prec$+ transmitt] are3 7#a7 ! magnetic modulator1 if y use "o1 %\ld h an output ( #c-a_/b to #e amp]es2 7#b7 y w ne$ two #ej watt oscillator tubes ) sockets2 7#c7 two #aej watt rectifi] tubes ) sockets2 7#d7 an a]ial ammet] t reads to #e amp]es2 7#e7 ?ree #a mfd4 filt] cond5s]s 9 p>allel2 7#f7 two filt] cond5s]s ( #a mfd4 capacitance t w /& #agej volts2 & 7#f7 a #cjj milliamp]e filt] reactor4 ,! app>atus is wir$ up z %[n 9 ,fig4 #ic4 ,,*apt] ,,xix ,,! ,,op]ation ,,( ,,vacuum ,,tube ,,transmitt]s ,! ?ree =ego+ *apt]s expla9$ 9 detail ! design & con/ruction ( 7#a7 two k9ds ( ,c4 ,w4 telegraph transmitt]s1 & 7#b7 two k9ds ( wireless telephone transmitt]s1 ! diff]5ce betwe5 !m be+ :e!r !y us$ 7,a7 a direct curr5t1 or 7,b7 an alt]nat+ curr5t z ! initial s\rce ( en]gy4 ,( c\rse !re are o!r diff]5ces betwe5 ^? ( l types z1 = in/ance1 ! app>atus & connections us$ 7a7 9 ! key circuits1 & 7b7 9 ! microphone circuits4 ,b 9 all ( ! transmitt]s describ$ ( :atev] type or k9d ! same fundam5tal device is us$ = sett+ up su/a9$ oscillations & ?is is ! vacuum tube4 ,! ,op]ation ( ! ,vacuum ,tube ,oscillator4--,! op]ation ( ! vacuum tube 9 produc+ su/a9$ oscillations dep5ds on 7#a7 ! action ( ! tube z a valve 9 sett+ up ! oscillations 9 ! fir/ place & 7#b7 ! action ( ! grid 9 amplify+ ! oscillations ?us set up1 bo? ( :i* we expla9$ 9 ,*apt] ,,xiv4 ,9 t *apt] x 0 also po9t$ out t a v small *ange 9 ! grid pot5tial causes a correspond+ & l>g] *ange 9 ! am\nt ( curr5t fl[+ f ! plate to ! filam5t2 & t if a vacuum tube is us$ = ! production ( oscillations ! initial s\rce ( curr5t mu/ h a high voltage1 9 fact ! high] ! plate voltage ! m p[]ful w be ! oscillations4 ,to und]/& h[ oscillations are set up by a vacuum tube :5 a direct curr5t is appli$ to x1 take a look at ! simple circuits %[n 9 ,fig4 #id4 ,n[ :5 y close ! swit* ! voltage f ! batt]y *>ges ! cond5s] & keeps x *>g$ until y op5 x aga92 ! in/ant y d ?is ! cond5s] dis*>ges ?r\gh ! circuit :i* includes x & ! inductance coil1 & ! dis*>ge ( a cond5s] is always oscillatory4 ,illu/ration3 7,a7 & 7,b7 ,fig4 #id4 ,op]ation ( ,vacuum ,tube ,oscillators4 ,:]e an oscillator tube is includ$ 9 ! circuits z %[n at ,a & ,b 9 ,fig4 #id1 ! grid takes ! place ( ! swit* & any slight *ange 9 ! voltage ( ei!r ! grid or ! plate is suffici5t to />t a tra9 ( oscillations go+4 ,z ^! oscillations surge ?r\gh ! tube ! positive p>ts ( !m fl[ f ! plate to ! filam5t & ^! c>ry m ( ! direct curr5t ) !m4 ,to make a tube set up p[]ful oscillations !n1 x is only necess>y t an oscillation circuit %all be provid$ :i* w fe$ "p ( ! oscillations set up by ! tube back to ! grid circuit & :5 ?is is done ! oscillations w keep on be+ amplifi$ until ! tube rea*es ! limit ( its output4 ,illu/ration3 7,c7 ,fig4 #id4--;,h[ a ,direct ,curr5t ,sets up ,oscillations4 ,! ,op]ation ( ,c4 ,w4 ,telegraph ,transmitt]s ,) ,direct ,curr5t--,%ort ,di/ance ,c4 ,w4 ,transmitt]4--,9 ! transmitt] %[n 9 ! wir+ diagram 9 ,fig4 #gf ! positive "p ( ! #aaj volt direct curr5t is c>ri$ d[n f ! lamp socket ?r\gh "o side ( ! panel cut-out1 !nce ?r\gh ! *oke coil & to ! plate ( ! oscillator tube1 :5 ! latt] is *>g$ to ! positive sign4 ,! negative "p ( ! #aaj volt direct curr5t !n fl[s d[n ! o!r wire to ! filam5t s t !re is a diff]5ce ( pot5tial betwe5 ! plate & ! filam5t ( #aaj volts4 ,n[ :5 ! #f-volt batt]y curr5t is swit*$ on ! filam5t is heat$ to brilliancy1 & ! electrons ?r[n (f by x =m a conduct+ pa? betwe5 x & ! plate2 ! #aaj volt curr5t !n fl[s f ! latt] to ! =m]4 ,n[ foll[ ! wir+ f ! plate ov] to ! block+ cond5s]1 !nce to clip #c ( ! tun+ coil1 ?r\gh ! turns ( ! latt] to clip #b & ov] to ! filam5t &1 :5 ! latt] is heat$1 y h a clos$ oscillation circuit4 ,! oscillations surg+ 9 ! latt] set up o!r & l oscillations 9 ! tun+ coil betwe5 ! end ( :i* is connect$ ) ! grid1 ! a]ial & ! clip #b1 & ^! surge ?r\gh ! circuit =m$ by ?is portion ( ! coil1 ! grid cond5s] & ! filam5t2 ?is is ! amplify+ circuit & x corresponds to ! reg5]ative circuit ( a receiv+ set4 ,:5 oscillations are set up 9 x ! grid is alt]nately *>g$ to ! positive & negative signs4 ,^! rev]sals ( voltage set up /rong] & ev] /rong] oscillations 9 ! plate circuit z be=e expla9$4 ,n only d ! oscillations surge 9 ! clos$ circuits b !y run to & fro on ! a]ial wire :5 _! en]gy is radiat$ 9 ! =m ( electric waves4 ,! oscillations are v>i$ by means ( ! telegraph key :i* is plac$ 9 ! grid circuit z %[n 9 ,fig4 #gf4 ,! ,op]ation ( ! ,key ,circuit4--,! effect 9 a ,c4 ,w4 transmitt] :5 a telegraph key is connect$ 9 s]ies ) a buzz] & a batt]y & ^! are %unt$ ar\nd ! cond5s] 9 ! grid circuit1 is to rapidly *ange ! wave =m ( ! su/a9$ oscillations1 & h5ce1 ! l5g? ( ! waves t are s5t out4 ,:ile no s\nd c be he>d 9 ! headphones at ! receiv+ /ation s long z ! po9ts ( ! key are n 9 contact1 :5 !y are 9 contact ! oscillations are modulat$ & s\nds are he>d 9 ! headphones t correspond to ! frequ5cy ( ! buzz] 9 ! key circuit4 ,! ,op]ation ( ,c4 ,w4 ,telegraph ,transmitt]s ) ,direct ,curr5t4--,! *ief diff]5ces betwe5 ! long di/ance sets :i* use a direct curr5t1 i4e41 ^? describ$ 9 ,*apt] ,,xvi1 & ! %ort di/ance transmitt+ sets are t ! =m] use3 7#a7 a motor-g5]ator set = *ang+ ! l[ voltage direct curr5t into high voltage direct curr5t1 & 7#b7 a *opp] 9 ! key circuit4 ,! way ! motor-g5]ator *anges ! l[- into high-voltage curr5t has be5 expla9$ 9 ,*apt] ,,xvi4 ,! *opp] int]rupts ! oscillations surg+ ?r\gh ! grid circuit at a frequ5cy t ! e> c he>1 t is to say1 ab\t #hjj to #a1jjj times p] second4 ,:5 ! key is op51 ( c\rse1 ! su/a9$ oscillations set up 9 ! circuits w s5d out cont9u\s waves b :5 ! key is clos$ ^! oscillations are brok5 up & !n !y s5d out discont9u\s waves4 ,if a het]odyne receiv+ set1 see ,*apt] ,,xv1 is be+ us$ at ! o!r end y c disp5se ) ! *opp] & ! key circuit ne$$ is v mu* simplifi$4 ,! op]ation ( key circuits ( ! latt] k9d w be describ$ pres5tly4 ,! ,op]ation ( ,c4 ,w4 ,telegraph ,transmitt]s ) ,alt]nat+ ,curr5t--,) a ,s+le ,oscillator ,tube4--,:]e an oscillator tube telegraph transmitt] is op]at$ by a #aaj volt alt]nat+ curr5t z ! initial s\rce ( en]gy1 a buzz]1 *opp] or o!r int]ruptor is n ne$$ 9 ! key circuit4 ,?is is because oscillations are set up only :5 ! plate is en]giz$ ) ! positive "p ( ! alt]nat+ curr5t & ?is produces an int]mitt5t musical tone 9 ! headphones4 ,h5ce ?is k9d ( a s5d+ set is call$ a tone transmitt]4 ,s9ce oscillations are set up only by ! positive "p or voltage ( an alt]nat+ curr5t x is cle> t1 z a matt] ( fact1 ?is k9d ( a transmitt] does n s5d out cont9u\s waves & !re=e x is n a ,c4 ,w4 transmitt]4 ,?is is graphically %[n by ! curve ( ! wave =m ( ! alt]nat+ curr5t & ! oscillations t are set up by ! positive "p ( x 9 ,fig4 #ie4 ,:5ev] ! positive half ( ! alt]nat+ curr5t en]gizes ! plate !n oscillations are set up by ! tube &1 conv]sely1 :5 ! negative half ( ! curr5t *>ges ! plate no oscillations are produc$4 ,illu/ration3 ,fig4 #ie4--,positive ,voltage only sets up ,oscillations4 ,y w also obs]ve t ! oscillations set up by ! positive "p ( ! curr5t are n ( con/ant amplitude b />t at z]o ! in/ant ! positive "p beg9s to en]gize ! plate & !y keep on increas+ 9 amplitude z ! curr5t rises 9 voltage until ! latt] rea*es its maximum2 !n z x gradually drops aga9 to z]o ! oscillations decrease proportionately 9 amplitude ) x4 ,heat+ ! ,filam5t ) ,alt]nat+ ,curr5t4--,:]e an alt]nat+ curr5t p[] trans=m] is us$ to develop ! necess>y plate voltage a second second>y coil is g5]ally provid$ = heat+ ! filam5t ( ! oscillation tube4 ,?is is bett] ?an a direct curr5t = x adds to ! life ( ! filam5t4 ,:5 y use an alt]nat+ curr5t to heat ! filam5t keep x at ! same voltage r ?an at ! same amp]age 7curr5t /r5g?74 ,to d ?is y ne$ only to use a voltmet] across ! filam5t t]m9als in/ead ( an ammet] 9 s]ies ) x2 !n regulate ! voltage ( ! filam5t ) a rheo/at4 ,! ,op]ation ( ,c4 ,w4 ,telegraph ,transmitt]s ) ,alt]nat+ ,curr5t--,) ,two ,oscillator ,tubes4--,by us+ two oscillator tubes & connect+ !m up ) ! p[] trans=m] & oscillat+ circuits z %[n 9 ! wir+ diagram 9 ,fig4 #hc ! plates are positively en]giz$ alt]nately ) e rev]sal ( ! curr5t &1 consequ5tly1 !re is no "t p]iod betwe5 ! end+ ( ! oscillations set up by "o tube & ! beg9n+ ( ! oscillations set up by ! o!r tube4 ,9 o!r words ^! oscillations are su/a9$ b z 9 ! case ( ^? ( a s+le tube1 _! amplitude rises & falls4 ,?is k9d ( a set is call$ a full wave rectification transmitt]4 ,! waves radiat$ by ?is transmitt] c be receiv$ by ei!r a cry/al detector or a pla9 vacuum-tube detector b ! het]odyne receptor w give y bett] results ?an ei!r ( ! =ego+ types4 ,! ,op]ation ( ,wireless ,telephone ,transmitt]s ) ,direct ,curr5t--,%ort ,di/ance ,transmitt]4--,! op]ation ( ?is %ort di/ance wireless telephone transmitt]1 a wir+ diagram ( :i* is %[n 9 ,fig4 #he is exactly ! same z t ( ! ,direct ,curr5t ,%ort ,di/ance ,c4 ,w4 ,telegraph ,transmitt] already expla9$ 9 ?is *apt]4 ,! only diff]5ce 9 ! op]ation ( ^! sets is ! sub/itution ( ! microphone transmitt] = ! telegraph key4 ,! ,microphone ,transmitt]4--,! microphone transmitt] t is us$ to v>y1 or modulate1 ! su/a9$ oscillations set up by ! oscillator tube & circuits is %[n 9 ,fig4 #hd4 ,by ref]r+ to ! diagram at ,a 9 ?is figure y w readily und]/& h[ x op]ates4 ,:5 y speak into ! m\?piece ! s\nd waves1 :i* are waves 9 ! air1 imp+e ^u ! diaphragm & ^! set x into vibration--t is1 !y make x move to & fro4 ,:5 ! diaphragm moves t[>d ! back ( ! transmitt] x =ces ! c>bon granules t are 9 ! cup clos] toge!r2 ?is l[]s _! resi/ance & all[s m curr5t f ! batt]y to fl[ ?r\gh !m2 :5 ! pressure ( ! air waves is remov$ f ! diaphragm x spr+s back t[>d ! m\?-piece & ! c>bon granules loos5 up :5 ! resi/ance (f]$ by !m is increas$ & less curr5t c fl[ ?r\gh !m4 ,:]e ! oscillation curr5t 9 ! a]ial wire is small ! transmitt] c be connect$ directly 9 s]ies ) ! latt] :5 ! =m] w surge ?r\gh x4 ,z y speak into ! microphone transmitt] its resi/ance is v>i$ & ! curr5t /r5g? ( ! oscillations is v>i$ accord+ly4 ,! ,op]ation ( ,wireless ,telephone ,transmitt]s ) ,direct ,curr5t--,long ,di/ance ,transmitt]s4--,9 ! wireless telephone transmitt]s = long di/ance "w :i* 7 %[n & describ$ 9 ! prec$+ *apt] a batt]y is us$ to en]gize ! microphone transmitt]1 & ^! two elem5ts are connect$ 9 s]ies ) a microphone modulator4 ,?is latt] device may be ei!r 7#a7 a telephone induction coil1 7#b7 a microphone trans=m]1 or 7#c7 a magnetic modulator2 ! fir/ two ( ^! devices /ep-up ! voltage ( ! batt]y curr5t & ! amplifi$ voltage ?us develop$ is impress$ on ! oscillations t surge ?r\gh ! clos$ oscillation circuit or ! a]ial wire sy/em accord+ to ! place :]e y connect x4 ,! ?ird device works on a diff]5t pr9ciple & ?is w be describ$ a little f>!r along4 ,! ,op]ation ( ,microphone ,modulators--,! ,induction ,coil4--,?is device is really a m9iature trans=m]1 see ,a 9 ,fig4 #hf1 & its purpose is to *ange ! #f volt direct curr5t t fl[s ?r\gh ! microphone into #ajj volts alt]nat+ curr5t2 9 turn1 ?is is impress$ on ! oscillations t are surg+ 9 ei!r 7#a7 ! grid circuit z %[n at ,a 9 ,fig4 #hi1 & 9 ,fig4 #ij1 7#b7 ! a]ial wire sy/em1 z %[n at ,b 9 ,fig4 #hi & ,fig4 #ic4 ,:5 ! curr5t f ! batt]y fl[s ?r\gh ! prim>y coil x magnetizes ! s(t iron core & z ! microphone v>ies ! /r5g? ( ! curr5t ! high voltage alt]nat+ curr5ts set up 9 ! second>y coil ( ! induction coil are likewise v>i$1 :5 !y are impress$ ^u & modulate ! oscillat+ curr5ts4 ,! ,microphone ,trans=m]4--,?is is an induction coil t is design$ especially = wireless telephone modulation4 ,! iron core ( ?is trans=m] is also ( ! op5 magnetic circuit type1 see ,a 9 ,fig4 #hg1 & ! ratio ( ! turns ,footnote3 ,see ,*apt] ,,vi ( ! prim>y & ! second>y coil is su* t :5 ! second>y curr5t is impress$ ^u ei!r ! grid circuit or ! a]ial wire sy/em x controls ! oscillations fl[+ ?r\gh x ) ! greate/ effici5cy4 ,! ,magnetic ,modulator4--,?is piece ( app>atus is also call$ a magnetic amplifi]4 ,! iron core is =m$ ( v ?9 plates1 or lam9ations z !y are call$1 & ?is p]mits high-frequ5cy oscillations to surge 9 a coil w\nd on x4 ,9 ?is trans=m]1 see ,a 9 ,fig4 #hh1 ! curr5t fl[+ ?r\gh ! microphone v>ies ! magnetic p]meability ( ! s(t iron core by ! magnetic saturation ( ! latt]4 ,s9ce ! microphone curr5t is absolutely di/9ct f ! oscillat+ curr5ts surg+ ?r\gh ! coil ( ! trans=m] a v small direct curr5t fl[+ ?r\gh a coil on ! latt] w v>y or modulate v l>ge oscillat+ curr5ts surg+ ?r\gh ! =m]4 ,x is %[n connect$ 9 ! a]ial wire sy/em at ,a 9 ,fig4 #hh1 & 9 ,fig4 #ic4 ,op]ation ( ! ,vacuum ,tube z a ,modulator4--,:]e a microphone modulator ( ! induction coil or microphone trans=m] type is connect$ 9 ! grid circuit or a]ial wire sy/em ! modulation is n v effective1 b by us+ a second tube z a modulator1 z %[n 9 ,fig4 #ij1 an effici5t degree ( modulation c be _h4 ,n[ !re are two me?ods by :i* a vacuum tube c be us$ z a modulator & ^! are3 7#a7 by ! absorption ( ! en]gy ( ! curr5t set up by ! oscillator tube1 & 7#b7 by v>y+ ! direct curr5t t en]gizes ! plate ( ! oscillator tube4 ,! fir/ ( ^! two me?ods is n us$ because x absorbs ! en]gy ( ! oscillat+ curr5t produc$ by ! tube & x is !re=e wa/eful4 ,! second me?od is an effici5t "o1 z ! direct curr5t is v>i$ be=e x passes into ! oscillator tube4 ,?is is suffici5t reason = describ+ only ! second me?od4 ,! voltage ( ! grid ( ! modulator tube is v>i$ by ! second>y coil ( ! induction coil or microphone trans=m]1 above describ$4 ,9 ?is way ! modulator tube acts l a v>iable resi/ance b x amplifies ! v>iations impress$ on ! oscillations set up by ! oscillator tube4 ,z ! magnetic modulator does ! same ?+ a vacuum tube us$ z a modulator is n ne$$ :]e ! =m] is employ$4 ,= ?is reason a magnetic modulator is ! *eape/ 9 ! long run4 ,! ,op]ation ( ,wireless ,telephone ,transmitt]s ) ,alt]nat+ ,curr5t4--,:]e an initial alt]nat+ curr5t is us$ = wireless telephony1 ! curr5t mu/ be rectifi$ fir/ & !n smoo!d out be=e pass+ into ! oscillator tube to be conv]t$ into oscillations4 ,fur!r s t ! oscillations w be su/a9$1 two oscillator tubes mu/ be us$1 &1 f9ally1 9 ord] t ! oscillations may n v>y 9 amplitude ! alt]nat+ curr5t mu/ be fir/ *ang$ into direct curr5t by a pair ( rectifi] vacuum tubes1 z %[n 9 ,fig4 #ic4 ,:5 ?is is done ! plates w be positively *>g$ alt]nately ) e rev]sal ( ! curr5t 9 :i* case !re w be no break 9 ! cont9uity ( ! oscillations set up & !re=e 9 ! waves t are s5t out4 ,! ,op]ation ( ,rectifi] ,vacuum ,tubes4--,! vacuum tube rectifi] is simply a two electrode vacuum tube4 ,! way 9 :i* x *anges a comm]cial alt]nat+ curr5t into pulsat+ direct curr5t is ! same z t 9 :i* a two electrode vacuum tube detector *anges an oscillat+ curr5t into pulsat+ direct curr5ts & ?is has be5 expla9$ 9 detail "u ! head+ ( ,! ,op]ation ( a ,two ,electrode ,vacuum ,tube ,detector 9 ,*apt] ,,xii4 ,9 ! ,c4 ,w4 ,telegraph ,transmitt+ ,sets describ$ 9 ,*apt] ,,xvii1 ! oscillator tubes act z rectifi]s z well z oscillators b = wireless telephony ! alt]nat+ curr5t mu/ be rectifi$ fir/ s t a cont9u\s direct curr5t w result4 ,! ,op]ation ( ,reactors & ,cond5s]s4--,a reactor is a s+le coil ( wire w\nd on an iron core1 see ,fig4 #ij & ,a 9 ,fig4 #ia1 & x %\ld pref]ably h a l>ge inductance4 ,! reactor = ! plate & grid circuit ( a wireless telephone transmitt] :]e "o or m tubes are us$ z modulators z %[n 9 ! wir+ diagram 9 ,fig4 #ij1 & ! filt] reactor %[n 9 ,fig4 #ib1 op]ate 9 ! same way4 ,:5 an alt]nat+ curr5t fl[s ?r\gh a coil ( wire ! rev]sals ( ! curr5t set up a c\nt] electromotive =ce 9 x :i* opposes1 t is reacts1 on ! curr5t1 & ! high] ! frequ5cy ( ! curr5t ! great] w be ! reactance4 ,:5 ! positive half ( an alt]nat+ curr5t is made to fl[ ?r\gh a l>ge resi/ance ! curr5t is smoo!d out b at ! same "t a l>ge am\nt ( its en]gy is us$ up 9 produc+ heat4 ,b :5 ! positive half ( an alt]nat+ curr5t is made to fl[ ?r\gh a l>ge inductance x acts l a l>ge resi/ance z be=e & likewise smoo?s out ! curr5t1 b none ( its en]gy is wa/$ 9 heat & s a coil hav+ a l>ge inductance1 :i* is call$ an inductive reactance1 or j reactor = %ort1 is us$ to smoo? out1 or filt]1 ! alt]nat+ curr5t aft] x has be5 *ang$ into a pulsat+ direct curr5t by ! rectifi] tubes4 ,a cond5s] also has a reactance effect on an alt]nat+ curr5t b diff]5t f an induction coil ! l[] ! frequ5cy ! great] w be ! reactance4 ,= ?is reason bo? a filt] reactor & filt] cond5s]s are us$ to smoo? out ! pulsat+ direct curr5ts4 ,,*apt] ,,xx ,,h[ ,,to ,,make ,a ,,receiv+ ,,set ,,= #e4jj ,,or ,,less ,9 ! *apt]s on ,receptors y h be5 told h[ to build up high-grade sets4 ,b !re are ?\s&s ( boys1 &1 probably1 n a few m51 :o _c af=d to inve/ #be4jj1 m or less1 9 a receiv+ set & w\ld l to exp]im5t 9 a small way4 ,! foll[+ set is inexp5sive1 & ) ?is *eap1 little portable receptor y c get ! ,morse code f /ations a hundr$ miles di/ant & messages & music f broadca/+ /ations if y d n live too f> away f !m4 ,all y ne$ = ?is set are3 7#a7 a cry/al detector1 7#b7 a tun+ coil & 7#c7 an e>phone4 ,y c make a cry/al detector out ( a c\ple ( b9d+ po/s1 a bit ( gal5a & a piece ( brass wire1 or1 bett]1 y c buy "o all ready to use = #ej c5ts4 ,illu/ration3 ,wireless ,receptor1 ! size ( a ,safety ,mat* ,box4 ,a ,y\?ful ,g5ius 9 ! p]son ( ,k5ne? ,r4 ,h9man1 ,:o is only twelve ye>s old1 has made a ,wireless ,receiv+ ,set t fits neatly into a ,safety ,mat* ,box4 ,) ?is ,in/rum5t & a ,pair ( ,ord9>y ,receiv]s1 ,he is able to cat* n only ,code ,messages b ! regul> ,broadca/+ ,programs f ,/ations ,tw5ty & ,?irty ,miles ,di/ant4 ,! ,cry/al ,detector4--,?is is kn[n z ! ,rasco baby detector & x is made & sold by ! ,radio ,specialty ,company1 #if ,p>k ,place1 ,new ,york ,city4 ,x is %[n 9 ,fig4 #if4 ,! base is made ( black composition & on x is m\nt$ a /&>d 9 :i* a rod slides & on "o end ( ?is !re is fix$ a h>d rubb] adju/+ knob :ile ! o!r end c>ries a ?9 piece ( phosphor-bronze wire1 call$ a cat-:isk]4 ,to secure ! gal5a cry/al 9 ! cup y simply unscrew ! knurl$ cap1 place x 9 ! cavity ( ! po/ & screw ! cap back on aga94 ,! free end ( ! cat-:isk] wire is !n adju/$ s t x w re/ lightly on ! expos$ "p ( ! gal5a4 ,illu/ration3 ,fig4 #if4--,rasco ,baby ,cry/al ,detector4 ,! ,tun+ ,coil4--,y w h to make ?is tun+ coil1 :i* y c d at a co/ ( less ?an #a4jj1 z ! *eape/ tun+ coil y c buy co/s at lea/ #c4jj1 & we ne$ ! re/ ( our #e4jj to inve/ 9 ! e>phone4 ,get a c>dbo>d tube1 su* z is us$ = mail+ purposes1 #b in*es 9 diamet] & #c in*es long1 see ,a 9 ,fig4 #ig4 ,n[ w9d on #bej turns ( ,no4 #dj ,br[n & ,%>pe gauge pla9 enamel$ magnet wire4 ,y c use ,no4 #dj d\ble cotton cov]$ magnet wire1 9 :i* case y w h to %ellac ! tube & ! wire aft] y get x on4 ,illu/ration3 ,fig4 #ig4--;,h[ ! ,tun+ ,coil is ,made4 ,z y w9d on ! wire take (f a tap at e #ae? turn1 t is1 scrape ! wire & sold] on a piece ab\t #g in*es long1 z %[n 9 ,fig4 #ii2 & d ?is until y h #f taps tak5 (f4 ,in/ead ( leav+ ! wires outside ( ! tube br+ !m to ! inside ( x & !n out ?r\gh "o ( ! op5 ends4 ,n[ buy a r\nd wood-base swit* ) #g contact po9ts on x z %[n at ,b 9 ,fig4 #ig4 ,?is w co/ y #be or #ej c5ts4 ,! ,headphone4--,an ord9>y ,bell telephone receiv] is ( small use = wireless "w z x is w\nd to too l[ a resi/ance & ! diaphragm is mu* too ?ick4 ,if y happ5 to h a ,bell phone y c rew9d x ) ,no4 #dj s+le cov]$ silk magnet wire1 or enamel$ wire ( ! same size1 :5 its s5sitivity w be v greatly improv$4 ,!n y mu/ get a ?9 diaphragm & ?is %\ld n be enamel$1 z ?is t5ds to damp5 ! vibrations ( x4 ,y c get a diaphragm ( ! "r k9d = #e c5ts4 ,! bett] way1 ?\gh1 is to buy an e>phone made especially = wireless "w4 ,y c get "o w\nd to #ajjj ohms resi/ance = #a4ge & ?is price includes a cord4 ,footnote3 ,?is is ,mesco1 ,no4 #dgj wireless phone4 ,sold by ! ,manhattan ,electrical ,supply ,co41 ,p>k ,place1 ,n4,y4,c4 ,= #a4jj extra y c get a head-b& = x1 & !n y\r phone w look l ! "o pictur$ 9 ,fig4 #ih4 ,illu/ration3 ,fig4 #ih4--,mesco #ajjj ,ohm ,head ,set4 ,h[ to ,m\nt ! ,p>ts4--,n[ m\nt ! coil on a wood base1 #a_/b or #a in* ?ick1 #c-a_/b in*es wide & #e-a_/b in*es long1 & !n connect "o end ( ! coil to "o ( ! end po9ts on ! swit*1 & connect ea* succe$+ tap to "o ( ! swit* po9ts1 z %[n s*ematically 9 ,fig4 #ii & diagrammatically 9 ,fig4 #ajj4 ,?is done1 screw ! swit* d[n to ! base4 ,f9ally screw ! detector to ! base & screw two b9d+ po/s 9 front ( ! coil4 ,^! are = ! e>phone4 ,illu/ration3 ,fig4 #ii4--,s*ematic ,lay\t ( #e4jj ,receiv+ ,set4 ,illu/ration3 ,fig4 #ajj4--,wir+ ,diagram = #e4jj ,receiv+ ,set4 ,! ,cond5s]4--,y d n h to connect a cond5s] across ! e>phone b if y d y w improve ! receiv+ qualities ( ! receptor4 ,h[ to ,connect ,up ! ,receptor4--,n[ connect up all ! p>ts z %[n 9 ,figs4 #ii & #ajj1 !n connect ! lead+-9 wire ( ! a]ial ) ! lev] ( ! swit*2 & connect ! free end ( ! tun+ coil ) ! gr\nd4 ,if y h no a]ial wire try hook+ x up to a ra9 pipe t is n gr\nd$ or ! /eel frame ( an umbrella4 ,= a gr\nd y c use a wat] pipe1 an iron pipe driv5 into ! gr\nd1 or a hydrant4 ,put on y\r headphone1 adju/ ! detector & move ! lev] ov] ! swit* contacts until x is 9 adju/m5t & !n1 if all y\r connections are prop]ly made1 y %\ld be able to pick up messages4 ,illu/ration3 ,wireless ,set made into a ,r+1 design$ by ,alfr$ ,g4 ,r9eh>t1 ( ,elizabe?1 ,new ,j]sey4 ,?is little ,receptor is a ,practical ,set2 x w receive ,messages1 ,conc]ts1 etc41 ,measures #a by #e_/h by #g_/h4 ,an ord9>y ,umbrella is us$ z an ,a]ial4 ,,app5dix ,,useful ,,in=mation ,,abbreviations ,,( ,,units ,unit ,abbreviation amp]e amp4 amp]e-h\rs amp4-hr4 c5timet] cm4 c5timet]-gram-second c4g4s4 cubic c5timet]s cm4#c cubic in*es cu4 94 cycles p] second degrees ,c5tigrade ,c4 degrees ,fahr5heit ,f4 feet ft4 foot-p\nds ft4-lb4 grams g4 h5ries h4 in*es 94 kilograms kg4 kilomet]s km4 kil[atts kw4 kil[att-h\rs kw4-hr4 kilovolt-amp]es kv4-a4 met]s m4 micr(>ads ,greek3 muf4 micromicr(>ads ,greek3 mu muf4 millih5ries mh4 millimet]s mm4 p\nds lb4 seconds sec4 squ>e c5timet]s cm4#b squ>e in*es sq4 94 volts v4 watts w4 ,,prefixes ,,us$ ,,) ,,metric ,,sy/em ,,units ,prefix ,abbreviation ,mean+ micro ,greek3 mu4 #a million? milli m4 #a ?\s&? c5ti c4 #a hundr$? deci d4 #a t5? deka dk4 #aj hekto h4 #a hundr$ kilo k4 #a ?\s& mega m4 #a million ,,symbols ,,us$ ,,= ,,v>i\s ,,quantities ,quantity ,symbol capacitance ,c conductance g c\pl+ co-effici5t k curr5t1 in/antane\s i curr5t1 effective value ,i decrem5t ,greek3 delta dielectric con/ant ,greek3 alpha electric field int5sity ,greek3 epsilon electromotive =ce1 in/antane\s value ,e electromotive =ce1 effective value ,f en]gy ,w =ce ,f frequ5cy f frequ5cy x #b;,greek3 pi ,greek3 omega imp$ance ,z inductance1 self ,l inductance1 mutual ,m magnetic field int5sity ,a magnetic flux ,greek3 ,phi magnetic induction ,b p]iod ( a complete oscillation ,t pot5tial diff]5ce ,v quantity ( electricity ,q ratio ( ! circumf]5ce ( a circle to its diamet] #c4adaf ,greek3 pi reactance ,x resi/ance ,r "t t velocity v velocity ( light c wave l5g? ,greek3 lambda wave l5g? 9 met]s ,greek3 lambdam "w ,w p]meability ,greek3 mu ,squ>e root ,ma?3 squ>e root ,,table ,,( ,,enamel$ ,,wire ,no4 ( ,turns ,turns ,ohms p] ,wire1 p] p] ,cubic ,in* ,b4 ,s4 ,l9e> ,squ>e ( ,gauge ,in* ,in* ,w9d+ #bj #cj #hhe 4#gdh #bb #cg #adjj #a4hh #bd #df #bafj #d4fa #bf #eh #cdfj #aa4hj #bh #gc #edjj #bi4bj #cj #ia #hbfj #gj4ij #cb #aaf #ba1jjj #gedg4jj #cd #ade #ac1dcj #bifh4jj #cf #agh #ca1hbj #ajih4jj #ch #bcb #ed1jhj #def4jj #dj #bid #hf1ejj #ahc4jj ,,table ,,( ,,frequ5cy ,,& ,,wave ,,l5g?s ,w4 ,l4--,wave ,l5g?s 9 ,met]s4 ,f4--,numb] ( ,oscillations p] ,second4 ,o4 or squ>e root ,l4 ,c4 is call$ ,oscillation ,con/ant4 ,c4--,capacity 9 ,micr(>ads4 ,l4--,inductance 9 ,c5timet]s4 #ajjj ,c5timet]s #a ,microh5ry4 ,w4,l4 ,f ,o ,l4,c4 #ej #f1jjj1jjj 4#hci 4#gjci #ajj #c1jjj1jjj #a4fh #b4hb #aej #b1jjj1jjj #b4eb #f4ce #bjj #a1ejj1jjj #c4cf #aa4bi #bej #a1bjj1jjj #d4ai #ag4ee #cjj #a1jjj1jjj #e4je #be4cj #cej #heg1ajj #e4hg #cd4df #djj #gej1jjj #f4ga #de4jc #dej #fff1gjj #g4ee #eg4jj #ejj #fjj1jjj #h4ci #gj4ci #eej #ede1djj #i4bc #he4ai #fjj #ejj1jjj #aj4jg #aja4da #gjj #dbh1fjj #aa4gd #acg4hc #hjj #cge1jjj #ac4db #ahj4aj #ijj #ccc1cjj #ae4aj #bbh4ja #a1jjj #cjj1jjj #af4gh #bha4eg #a1ajj #bgb1gcj #ah4de #cdj4dj #a1bjj #bej1jjj #bj4ac #dje4bj #a1cjj #bcj1gfj #ba4ha #dge4gj #a1djj #bad1chj #bc4di #eea4hj #a1ejj #bjj1jjj #be4ag #fcc4ej #a1fjj #ahg1ejj #bf4hd #gbj4dj #a1gjj #agf1dfj #bh4eb #hac4dj #a1hjj #aff1fgj #cj4bj #iab4jj #a1ijj #aeg1hjj #ca4hh #a1jaf4dj #b1jjj #aej1jjj #cc4ee #a1abe4fj #b1ajj #adb1hej #ce4bc #a1bda4bj #b1bjj #acf1cfj #cf4ia #a1cfb4dj #b1cjj #acj1dcj #ch4ei #a1dhi4cj #b1djj #abe1jjj #dj4bg #a1fba4hj #b1ejj #abj1jjj #da4ie #a1gei4gj #b1fjj #aae1chj #dc4fb #a1ijb4fj #b1gjj #aaa1aaj #de4cj #b1jeb4jj #b1hjj #ajg1adj #df4hi #b1bjg4jj #b1ijj #ajc1dej #dh4ff #b1cff4cj #c1jjj #ajj1jjj #ej4cc #b1ecc4bj #d1jjj #ge1jjj #fg4aa #d1ejd4jj #e1jjj #fj1jjj #hc4hi #g1jch4jj #f1jjj #ej1jjj #ajj4g #aj1acj4jj #g1jjj #da1hjj #aag4c #ac1fcj4jj #h1jjj #cg1ejj #acd4a #ah1jjj4jj #i1jjj #cc1cjj #aea4j #bb1hbj4jj #aj1jjj #cj1jjj #afg4i #bh1aej4jj #aa1jjj #bg1cjj #ahd4h #cd1aej4jj #ab1jjj #be1jjj #bja4e #dj1fjj4jj #ac1jjj #bc1ajj #bah4c #dg1fjj4jj #ad1jjj #ba1djj #bce4j #ee1bjj4jj #ae1jjj #bj1jjj #beb4j #fc1ejj4jj #af1jjj #ah1gej #bfi4j #gb1cjj4jj ,,pronunciation ,,( ,,greek ,,lett]s ,_m ( ! physical quantities use ,greek lett]s = symbols4 ,! foll[+ is ! ,greek alphabet ) ! way ! lett]s are pron\nc$3 a alpha b beta g gamma d delta e epsilon z zeta ae eta ? !ta i iota k kappa l lambda m mu n nu x ,xi7,zi7 o omicron p pi r rho s sigma t tau u upsilon ph phi * *i ps psi o omega ,,table ,,( ,,sp>k+ ,,di/ances ,9 ,air = ,v>i\s ,voltages betwe5 ,ne$le ,po9ts ,volts ,di/ance ,in*es ,c5timet] #e1jjj 4#bbe 4#eg #aj1jjj 4#dgj #a4ai #ae1jjj 4#gbe #a4hd #bj1jjj #a4jjj #b4ed #be1jjj #a4cjj #c4cj #cj1jjj #a4fbe #d4aj #ce1jjj #b4jjj #e4aj #dj1jjj #b4dej #f4bj #de1jjj #b4ie #g4ej #ej1jjj #c4ee #i4ij #fj1jjj #d4fe #aa4h #gj1jjj #e4he #ad4i #hj1jjj #g4aj #ah4j #ij1jjj #h4ce #ba4b #ajj1jjj #i4fj #bd4d #aaj1jjj #aj4ge #bg4c #abj1jjj #aa4he #cj4a #acj1jjj #ab4ie #cb4i #adj1jjj #ac4ie #ce4d #aej1jjj #ae4jj #ch4a ,,feet ,,p] ,,p\nd ,,( ,,insulat$ ,,magnet ,,wire ,no4 ( ,s+le ,d\ble ,s+le ,d\ble ,b4 ,s4 ,cotton1 ,cotton1 ,silk1 ,silk1 ,enamel ,gauge #d-,mils #h-,mils #a-c_/d-,mils #d-,mils #bj #caa #bih #cai #cab #cbj #ba #chi #cgj #djh #chi #djd #bb #dhh #dfa #ejc #dih #eji #bc #fab #ehd #fcf #fca #fdb #bd #gfb #gde #hjj #ggi #haj #be #ieg #ijc #a1jje #iff #a1jai #bf #a1aib #a1aah #a1bfe #a1bjb #a1bhf #bg #a1dhh #a1dbb #a1eij #a1edc #a1fbj #bh #a1heb #a1gei #a1igb #a1iag #b1jdb #bi #b1cge #b1bjg #b1egj #b1dce #b1egj #cj #b1hfj #b1ecd #c1ade #b1ijj #c1bdj #ca #c1hjj #b1gfh #c1idc #c1fhc #d1jhb #cb #d1cge #c1gcg #d1iej #d1fed #e1acb #cc #e1eij #d1fig #f1ahj #e1fhi #f1dde #cd #f1ejj #f1afh #g1gdj #g1aaa #h1jic #ce #h1jej #f1gcg #i1fjj #h1ehd #aj1aig #cf #i1hbj #g1hgg #ab1jjj #aj1jci #ab1hac #cg #aa1hfj #i1cji #ae1jjj #aj1fff #af1aaj #ch #ad1cjj #aj1fcf #ah1ffj #ad1bbb #bj1bgd #ci #ag1acj #aa1ijg #bc1aej #af1eaf #be1eai #dj #ba1eij #ad1bbb #bh1gjj #ba1ccc #cb1ajg ,,int]national ,,morse ,,code ,,& ,,conv5tional ,,signals ,,to ,,be ,,us$ ,,= ,,all ,,g5]al ,,public ,,s]vice ,,radio ,,communication #a4 ,a da% is equal to ?ree dots4 #b4 ,! space betwe5 p>ts ( ! same lett] is equal to "o dot4 #c4 ,! space betwe5 two lett]s is equal to ?ree dots4 #d4 ,! space betwe5 two words is equal to five dots4 ,note3 p]iod d5otes ,morse dot1 hyph5 d5otes ,morse da% ,a 4- ,b -444 ,c -4-4 ,d -44 ,e 4 ,f 44-4 ,g --4 ,h 4444 ,i 44 ,j 4--- ,k -4- ,l 4-44 ,m -- ,n -4 ,o --- ,p 4--4 ,q --4- ,r 4-4 ,s 444 ,t - ,u 44- ,v 444- ,w 4-- ,x -44- ,y -4-- ,z --44 7,g]man7 4-4- or 7,spani%-,sc&9avian7 4--4- ,,* 7,g]man-,spani%7 ---- 7,fr5*7 44-44 7,spani%7 --4-- 7,g]man7 ---4 7,g]man7 44-- #a 4---- #b 44--- #c 444-- #d 4444- #e 44444 #f -4444 #g --444 #h ---44 #i ----4 #j ----- ,p]iod 44 44 44 ,semicolon -4-4-4 ,comma -4-4-4 ,colon ---444 ,int]rogation 44--44 ,exclamation po9t --44-- ,apo/rophe 4----4 ,hyph5 -4444- ,b> indicat+ fraction -44-4 ,p>5!sis -4--4- ,inv]t$ commas 4-44-4 ,und]l9e 44--4- ,d\ble da% -444- ,di/ress ,call 444---444 ,att5tion call to prec$e e transmission -4-4- ,g5]al inquiry call -4-4 --4- ,f 7de7 -44 4 ,invitation to transmit 7g ahead7 -4- ,w>n+--high p[] --44-- ,"q 7please repeat aft] 4447--int]rupt+ long messages 44--44 ,wait 4-444 ,break 7,bk47 7d\ble da%7 -444- ,und]/& 444-4 ,error 44444444 ,receiv$ 7,o4,k47 4-4 ,position report 7to prec$e all position messages7 - 4-4 ,end ( ea* message 7cross7 4-4-4 ,transmission f9i%$ 7end ( "w7 7conclusion ( correspond5ce7 444-4- ,,int]national ,,radiotelegraphic ,,conv5tion ,,li/ ,,( ,,abbreviations ,,to ,,be ,,us$ ,,9 ,,radio ,,communication ,,abbreviation ,,"q ,,answ] ,,or ,,reply ,,prb ,d y wi% to communicate ,i wi% to communicate by means by means ( ! ,int]national ( ! ,int]national ,signal ,code4 ,signal ,code8 ,,qra ,:at %ip or coa/ /ation is ,?is is4444 t8 ,,qrb ,:at is y\r di/ance8 ,my di/ance is4444 ,,qrc ,:at is y\r true be>+8 ,my true be>+ is4444 ,,qrd ,:]e are y b\nd =8 ,i am b\nd =4444 ,,qrf ,:]e are y b\nd f8 ,i am b\nd f4444 ,,qrg ,:at l9e d y belong to8 ,i belong to ! 444 ,l9e4 ,,qrh ,:at is y\r wave l5g? 9 ,my wave l5g? is 444 met]s4 met]s8 ,,qrj ,h[ _m words h y to s5d8 ,i h 444 words to s5d4 ,,qrk ,h[ d y receive me8 ,i am receiv+ well4 ,,qrl ,are y receiv+ badly8 ,i am receiv+ badly4 ,please ,%all ,i s5d #bj8 s5d #bj4 444-4 444-4 = adju/m5t8 = adju/m5t4 ,,qrm ,are y be+ int]f]$ )8 ,i am be+ int]f]$ )4 ,,qrn ,are ! atmosph]ics /rong8 ,atmosph]ics are v /rong4 ,,qro ,%all ,i increase p[]8 ,increase p[]4 ,,qrp ,%all ,i decrease p[]8 ,decrease p[]4 ,,qrq ,%all ,i s5d fa/]8 ,s5d fa/]4 ,,qrs ,%all ,i s5d sl[]8 ,s5d sl[]4 ,,qrt ,%all ,i /op s5d+8 ,/op s5d+4 ,,qru ,h y any?+ = me8 ,i h no?+ = y4 ,,qrv ,are y ready8 ,i am ready4 ,all "r n[4 ,,qrw ,are y busy8 ,i am busy 7or3 ,i am busy )44474 ,please d n int]f]e4 ,,qrx ,%all ,i /& by8 ,/& by4 ,i w call y :5 requir$4 ,,qry ,:5 w be my turn8 ,y\r turn w be ,no4444 ,,qrz ,are my signals weak8 ,y signals are weak4 ,,qsa ,are my signals /rong8 ,y signals are /rong4 ,,qsb ,is my tone bad8 ,! tone is bad4 ,is my sp>k bad8 ,! sp>k is bad4 ,,qsc ,is my spac+ bad8 ,y\r spac+ is bad4 ,,qsd ,:at is y\r "t8 ,my "t is4444 ,,qsf ,is transmission to be 9 ,transmission w be 9 alt]nate ord] or 9 s]ies8 alt]nate ord]4 ,,qsg ,transmission w be 9 a s]ies ( #e messages4 ,,q% ,transmission w be 9 a s]ies ( #aj messages4 ,,qsj ,:at rate %all ,i collect =4448 ,collect4444 ,,qsk ,is ! la/ radiogram cancel$8 ,! la/ radiogram is cancel$4 ,,qsl ,did y get my receipt8 ,please ackn[l$ge4 ,,qsm ,:at is y\r true c\rse8 ,my true c\rse is444degrees4 ,,qsn ,are y 9 communication ) l&8 ,i am n 9 communication ) l&4 ,,qso ,are y 9 communication ) ,i am 9 communication )444 any %ip or /ation 7?r\gh44474 7or3 )44478 ,,qsp ,%all ,i in=m444t y are ,in=m444t ,i am call+ him4 call+ him8 ,,qsq ,is444call+ me8 ,y are be+ call$ by4444 ,,qsr ,w y =w>d ! radiogram8 ,i w =w>d ! radiogram4 ,,q/ ,h y receiv$ ! g5]al ,g5]al call to all /ations4 call8 ,,qsu ,please call me :5 y h ,w call :5 ,i h f9i%$4 f9i%$ 7or3 at444o'clock78 ,,qsv ,is public correspond5ce be+ ,public correspond5ce is be+ h&l$8 h&l$4 ,please d n int]f]e4 ,footnote3 ,public correspond5ce is any radio "w1 (ficial or private1 h&l$ on comm]cial wave l5g?s4 ,,qsw ,%all ,i increase my sp>k ,increase y\r sp>k frequ5cy4 frequ5cy8 ,,qsx ,%all ,i decrease my sp>k ,decrease y\r sp>k frequ5cy4 frequ5cy8 ,,qsy ,%all ,i s5d on a wavel5g? ,let u *ange to ! wave l5g? ( 444 met]s8 ( 444 met]s4 ,,qsz ,s5d ea* ^w twice4 ,i h difficulty 9 receiv+ y4 ,,qta ,repeat ! la/ radiogram4 ,:5 an abbreviation is foll[$ by a m>k ( int]rogation1 x ref]s to ! "q indicat$ = t abbreviation4 ,useful ,in=mation ,symbols ,us$ ,= ,app>atus alt]nator ammet] a]ial arc batt]y buzz] cond5s] v>iable cond5s] connection ( wires no connection c\pl$ coils v>iable c\pl+ detector gap1 pla9 gap1 qu5*$ gr\nd hot wire ammet] inductor v>iable inductor key resi/or v>iable resi/or swit* s4p4s4t4 s4p4d4t4 d4p4s4t4 d4p4d4t4 rev]s+ phone receiv] transmitt] !rmoelem5t trans=m] vacuum tube voltmet] *oke coil ,,def9itions ,,( ,,electric ,,& ,,magnetic ,,units ,! ohm is ! resi/ance ( a ?read ( m]cury at ! temp]ature ( melt+ ice1 #ad4deba grams 9 mass1 ( uni=m cross-section & a l5g? ( #ajf4cjj c5timet]s4 ,! amp]e is ! curr5t :i* :5 pass$ ?r\gh a solution ( nitrate ( silv] 9 wat] accord+ to c]ta9 specifications1 deposits silv] at ! rate ( #j4jjaaahjj ( a gram p] second4 ,! volt is ! electromotive =ce :i* produces a curr5t ( #a amp]e :5 /eadily appli$ to a conductor ! resi/ance ( :i* is #a ohm4 ,! c\lomb is ! quantity ( electricity transf]r$ by a curr5t ( #a amp]e 9 #a second4 ,! amp]e-h\r is ! quantity ( electricity transf]r$ by a curr5t ( #a amp]e 9 #a h\r & is1 !re=e1 equal to #cfjj c\lombs4 ,! f>ad is ! capacitance ( a cond5s] 9 :i* a pot5tial diff]5ce ( #a volt causes x to h a *>ge ( #a c\lomb ( electricity4 ,! h5ry is ! inductance 9 a circuit 9 :i* ! electromotive =ce induc$ is #a volt :5 ! induc+ curr5t v>ies at ! rate ( #a amp]e p] second4 ,! watt is ! p[] sp5t by a curr5t ( #a amp]e 9 a resi/ance ( #a ohm4 ,! j\le is ! en]gy sp5t 9 ,i second by a fl[ ( #a amp]e 9 #a ohm4 ,! horse-p[] is us$ 9 rat+ /eam ma*9]y4 ,x is equal to #gdf watts4 ,! kil[att is #a1jjj watts4 ,! units ( capacitance actually us$ 9 wireless "w are ! micr(>ad1 :i* is ! million? "p ( a f>ad1 because ! f>ad is too l>ge a unit2 & ! ,c4 ,g4 ,s4 electro/atic unit ( capacitance1 :i* is (t5 call$ ! c5timet] ( capacitance1 :i* is ab\t equal to #a4aa micr(>ads4 ,! units ( inductance commonly us$ 9 radio "w are ! millih5ry1 :i* is ! ?\s&? "p ( a h5ry2 & ! c5timet] ( inductance1 :i* is "o "o-?\s&? "p ( a microh5ry4 ,note4--,= fur!r in=mation ab\t electric & magnetic units get ! ,bureau ( ,/&>ds ,circul> ,no4 #fj1 call$ ,electric ,units & ,/&>ds1 ! price ( :i* is #ae c5ts2 also get ,sci5tific ,pap] ,no4 #bib1 call$ ,int]national ,sy/em ( ,electric & ,magnetic ,units1 price #aj c5ts4 ,^! & o!r in=mative pap]s c be _h f ! ,sup]9t5d5t ( ,docum5ts1 ,gov]nm5t ,pr9t+ ,(fice1 ,wa%+ton1 ,d4 ,c4 ,,wireless ,,books ,! ,admiralty ,manual ( ,wireless ,telegraphy4 #aibj4 ,publi%$ by ,8 ,maje/y's ,/ation]y ,(fice1 ,london4 ,ralph ,e4 ,bat*]4--,prep>$ ,radio ,measurem5ts4 #aiba4 ,wireless ,press1 ,inc41 ,new ,york ,city4 ,elm] ,e4 ,bu*]4--,practical ,wireless ,telegraphy4 #aiah4 ,wireless ,press1 ,inc41 ,new ,york ,city4 ,elm] ,e4 ,bu*]4--,vacuum ,tubes 9 ,wireless ,communication4 #aiai4 ,wireless ,press1 ,inc41 ,new ,york ,city4 ,elm] ,e4 ,bu*]4--,! ,wireless ,exp]im5t]'s ,manual4 #aibj4 ,wireless ,press1 ,inc41 ,new ,york ,city4 ,a4 ,fr$]ick ,coll9s4--,wireless ,telegraphy1 ,its ,hi/ory1 ,!ory1 & ,practice4 #aije4 ,mc,graw ,pub4 ,co41 ,new ,york ,city4 ,j4 ,h4 ,dell+]4--,pr9ciples ,und]ly+ ,radio ,communication4 #aiba4 ,signal ,corps1 ,u4 ,s4 ,army1 ,wa%+ton1 ,d4 ,c4 ,h4 ,m4 ,dorsett4--,wireless ,telegraphy & ,telephony4 #aibj4 ,wireless ,press1 ,ltd41 ,london4 ,j4 ,a4 ,flem+4--,pr9ciples ( ,electric ,wave ,telegraphy4 #aiai4 ,longmans1 ,gre5 & ,co41 ,london4 ,*>les ,b4 ,hayw>d4--,h[ to ,become a ,wireless ,op]ator4 #aiah4 ,am]ican ,te*nical ,society1 ,*icago1 ,ill4 ,g4 ,d4 ,rob9son4--,manual ( ,radio ,telegraphy & ,telephony4 #aibj4 ,unit$ ,/ates ,naval ,in/itute1 ,annapolis1 ,md4 ,rup]t ,/anley4--,textbook ( ,wireless ,telegraphy4 #aiai4 ,longmans1 ,gre5 & ,co41 ,london4 ,e4 ,w4 ,/one4--,elem5ts ( ,radio ,telegraphy4 #aiai4 ,d1 ,van ,no/r& ,co41 ,new ,york ,city4 ,l4 ,b4 ,turn]4--,wireless ,telegraphy & ,telephony4 #aiba4 ,cambridge ,univ]sity ,press4 ,cambridge1 ,engl&4 ,s5d to ! ,sup]9t5d5t ( ,docum5ts1 ,gov]nm5t ,pr9t+ ,(fice1 ,wa%+ton1 ,d4 ,c41 = a copy ( ,price ,li/ ,no4 #fd :i* li/s ! ,gov]nm5t's books & pamphlets on wireless4 ,x w be s5t to y free ( *>ge4 ,! ,gov]nm5t publi%es2 7#a7 ,a ,li/ ( ,comm]cial ,gov]nm5t & ,special ,wireless ,/ations1 e ye>1 price #ae c5ts2 7#b7 ,a ,li/ ( ,amateur ,wireless ,/ations1 ye>ly1 price #ae c5ts2 7#c7 ,a ,wireless ,s]vice ,bullet9 is publi%$ mon?ly1 price #e c5ts a copy1 or #be c5ts ye>ly2 & 7#d7 ,wireless ,communication ,laws ( ! ,unit$ ,/ates1 ! ,int]national ,wireless ,telegraphic ,conv5tion & ,regulations ,gov]n+ ,wireless ,op]ators & ! ,use ( ,wireless on ,%ips & ,l& ,/ations1 price #ae c5ts a copy4 ,ord]s = ! above publications %\ld be address$ to ! ,sup]9t5d5t ( ,docum5ts1 ,gov]nm5t ,pr9t+ ,(fice1 ,wa%+ton1 ,d4 ,c4 ,manufactur]s & ,deal]s 9 ,wireless ,app>atus & ,supplies3 ,adams-,morgan ,co41 ,upp] ,montclair1 ,n4 ,j4 ,am]ican ,h>d ,rubb] ,co41 #aa ,m]c] ,/reet1 ,new ,york ,city4 ,am]ican ,radio & ,rese>* ,corporation1 ,m$=d ,hillside1 ,mass4 ,bra* 7,l4 ,s47 ,mfg4 ,co41 #abg ,sussex ,ave41 ,new>k1 ,n4 ,j4 ,br&es 7,c47 ,inc41 #bcg ,lafayette ,/41 ,new ,york ,city4 ,bunnell 7,j4 ,h47 ,company1 ,p>k ,place1 ,new ,york ,city4 ,burgess ,batt]y ,company1 ,h>ris ,tru/ ,co4 ,bldg41 ,*icago1 ,ill4 ,clapp-,ea/man ,co41 #abj ,ma9 ,/41 ,cambridge1 ,mass4 ,connecticut ,telephone & ,telegraph ,co41 ,m]id51 ,conn4 ,cont95tal ,fib] ,co41 ,new>k1 ,del4 ,coto-,coil ,co41 ,provid5ce1 ,r4 ,i4 ,crosley ,mfg4 ,co41 ,c9c9nati1 ,ohio4 ,doolittle 7,f4 ,m471 #hag ,*apel ,/41 ,new ,hav51 ,conn4 ,edelman 7,philip ,e471 #i ,cortl&t ,/41 ,new ,york ,city4 ,edison ,/orage ,batt]y ,co41 ,orange1 ,n4 ,j4 ,electric ,specialty ,co41 ,/am=d1 ,conn4 ,electrose ,mfg4 ,co41 #fj ,wa%+ton ,/41 ,brooklyn1 ,n4 ,y4 ,g5]al ,electric ,co41 ,s*5ectady1 ,n4 ,y4 ,grebe 7,a4 ,h47 & ,co41 ,inc41 ,ri*mond ,hill1 ,n4 ,y4 ,c4 ,int]national ,brass & ,electric ,co41 #agf ,beekman ,/41 ,new ,york ,city4 ,int]national ,insulat+ ,co41 #be ,we/ #de? ,/41 ,new ,york ,city4 ,k+ ,amplitone ,co41 #hb ,*ur* ,/41 ,new ,york ,city4 ,k5n$y 7,col9 ,b47 ,co41 ,rialto ,bldg41 ,san ,francisco1 ,cal4 ,magnavox ,co41 ,oakl&1 ,cal4 ,manhattan ,electrical ,supply ,co41 ,p>k ,place1 ,n4 ,y4 ,m>%all-,g]k5 ,co41 ,tol$o1 ,ohio4 ,mi*igan ,pap] ,tube & ,c ,co41 #becf ,gr& ,riv] ,ave41 ,detroit1 ,mi*4 ,murdock 7,wm4 ,j47 ,co41 ,*elsea1 ,mass4 ,national ,c>bon ,co41 ,inc41 ,long ,isl& ,city1 ,n4 ,y4 ,pittsburgh ,radio & ,appliance ,co41 #aab ,diamond ,/41 ,pittsburgh1 ,pa1 ,radio ,corporation ( ,am]ica1 #bcc ,broadway1 ,new ,york ,city4 ,riley-,klotz ,mfg4 ,co41 #ag-ai ,mulb]ry ,/41 ,new>k1 ,n4 ,j4 ,radio ,specialty ,co41 #if ,p>k ,place1 ,new ,york ,city4 ,roll]-,smi? ,co41 #ae ,b>clay ,/41 ,new ,york ,city4 ,tuska 7,c4 ,d47 ,co41 ,h>t=d1 ,conn4 ,we/]n ,electric ,co41 ,*icago1 ,ill4 ,we/+h\se ,electric ,co41 ,pittsburgh1 ,pa4 ,we/on ,electrical ,in/rum5t ,co41 #agc ,we/on ,ave41 ,new>k1 ,n4 ,j4 ,we/field ,ma*9e ,co41 ,we/field1 ,mass4 ,,abbreviations ,,( ,,common ,,t]ms ,a4 44444444444444,a]ial ,a4,c4 444444444444,alt]nat+ ,curr5t ,a4,f4 444444444444,audio ,frequ5cy ,b4 & ,s4 4444444,br[n ,%>pe ,wire ,gauge ,c4 44444444444444,capacity or ,capacitance ,c4,g4,s4 4444444444,c5timet]-,gra9-,second ,cond4 44444444444,cond5s] ,c\p4 44444444444,c\pl] ,c4,w4 444444444444,cont9u\s ,waves ,d4,c4 444444444444,direct ,curr5t ,d4,p4,d4,t4 44444444,d\ble ,po9t ,d\ble ,?r[ ,d4,p4,s4,t4 44444444,d\ble ,po9t ,s+le ,?r[ ,d4,x4 444444444444,di/ance ,e4 44444444444444,%ort = ,electromotive ,=ce 7,volt7 ,e4,m4,f4 4444444444,electromotive ,=ce ,f4 44444444444444,filam5t or ,frequ5cy ,g4 44444444444444,grid ,gnd4 444444444444,gr\nd ,i4 44444444444444,curr5t ,/r5g? 7,amp]e7 ,i4,c4,w4 4444444444,int]rupt$ ,cont9u\s ,waves ,,kw4 4444444444444,kil[att ,l4 44444444444444,inductance ,l4,c4 444444444444,loose ,c\pl] ,litz4 44444444444,litz5draht ,mfd4 444444444444,micr(>ad ,neg4 444444444444,negative ,o4,t4 444444444444,oscillation ,trans=m] ,p4 44444444444444,plate ,prim4 44444444444,prim>y ,pos4 444444444444,positive ,r4 44444444444444,resi/ance ,r4,f4 444444444444,radio ,frequ5cy ,sec4 444444444444,second>y ,s4,p4,d4,t4 44444444,s+le ,po9t ,d\ble ,?r[ ,s4,p4,s4,t4 44444444,s+le ,po9t ,s+le ,?r[ ,s4,r4 444444444444,self ,rectify+ ,t4 44444444444444,telephone or ,p]iod 7"t7 ( ,complete ,oscillation ,tick4 44444444444,tickl] ,v4 44444444444444,pot5tial ,diff]5ce ,v>4 444444444444,v>iomet] ,v>4 ,cond4 444444,v>iable ,cond5s] ,v4,t4 444444444444,vacuum ,tube ,w4,l4 444444444444,wave ,l5g? ,x4 44444444444444,reactance ,,gloss>y ,a ,,batt]y4--,see ,batt]y ,a4 ,,abbreviations1 ,,code4--,abbreviations ( que/ions & answ]s us$ 9 wireless communication4 ,! abbreviation ( a "q is usually 9 ?ree lett]s ( :i* ! fir/ is ,q4 ,?us ,q ,r ,b is ! code abbreviation ( :at is y\r di/ance8 & ! answ] ,my di/ance is444 ,see ,page #cjf ,app5dix3 ,li/ ( ,abbreviations4 ,,abbreviations1 ,,units4--,abbreviations ( v>i\s units us$ 9 wireless electricity4 ,^! abbreviations are usually l[] case lett]s ( ! ,roman alphabet1 b occasionally ,greek lett]s are us$ & o!r signs4 ,?us amp]es is abbreviat$ amp41 micro1 :i* means "o million?1 ,greek3 mu1 etc4 ,see ,page #cja ,app5dix3 ,useful ,abbreviations4 ,,abbreviations ,,( ,,words ,,& ,,t]ms4--,lett]s us$ in/ead ( words & t]ms = %ort5+ !m up :]e !re is a con/ant repetition ( !m1 z ,a4,c4 = alt]nat+ curr5t2 ,c4,w4 = cont9u\s waves2 ,v4,t4 = vacuum tube1 etc4 ,see ,page #cab ,app5dix3 ,abbreviations ( ,common ,t]ms4 ,,a]ial4--,also call$ ant5na4 ,an a]ial wire4 ,"o or m wires susp5d$ 9 ! air & insulat$ f its supports4 ,x is ! a]ial t s5ds out ! waves & receives !m4 ,,a]ial1 ,,amateur4--,an a]ial suitable = s5d+ out #bjj met] wave l5g?s4 ,su* an a]ial wire sy/em mu/ n exce$ #abj feet 9 l5g? f ! gr\nd up to ! a]ial swit* & f ?is ?r\gh ! lead+-9 wire to ! end ( ! a]ial4 ,,a]ial ,,ammet]4--,see ,ammet]1 ,hot ,wire4 ,,a]ial1 ,,b$-,,spr+s4--,:]e an outdoor a]ial is n practicable b$-spr+s are (t5 made to s]ve ! purpose4 ,,a]ial ,,capacity4--,see ,capacity1 ,a]ial4 ,,a]ial ,,c\nt]poise4--,:]e x is n possible to get a good gr\nd an a]ial c\nt]poise or e>? capacity c be us$ to advantage4 ,! c\nt]poise is made l ! a]ial & is support$ directly "u x close to ! gr\nd b insulat$ f x4 ,,a]ial1 ,,directional4--,a flat-top or o!r a]ial t w transmit & receive ov] great] di/ances to & f "o direction ?an to & f ano!r4 ,,a]ial1 ,,gr\nd4--,signals c be receiv$ on a s+le long wire :5 x is plac$ on or buri$ 9 ! e>? or imm]s$ 9 wat]4 ,x is also call$ a gr\nd ant5na & an und]gr\nd a]ial4 ,,a]ial1 ,,loop4--,also call$ a coil a]ial1 coil ant5na1 loop a]ial1 loop ant5na & :5 us$ = ! purpose a direction f9d]4 ,a coil ( wire w\nd on a v]tical frame4 ,,a]ial ,,resi/ance4--,see ,resi/ance1 ,a]ial4 ,,a]ial ,,swit*4--,see ,swit* ,a]ial4 ,,a]ial ,,wire4--7#a7 ,a wire or wires t =m ! a]ial4 7#b7 ,wire t is us$ = a]ials2 ?is is usually copp] or copp] alloy4 ,,a]ial ,,wire ,,sy/em4--,an a]ial & gr\nd wire & t "p ( ! inductance coil :i* connects !m4 ,! op5 oscillation circuit ( a s5d+ or a receiv+ /ation4 ,,air ,,core ,,trans=m]4--,see ,trans=m]1 ,air ,core4 ,,amateur ,,a]ial ,,or ,,ant5na4--,see ,a]ial1 ,amateur4 ,,alt]nator4--,an electric ma*9e t g5]ates alt]nat+ curr5t4 ,,alphabet1 ,,int]national ,,code4--,a modifi$ ,morse alphabet ( dots & da%es orig9ally us$ 9 ,cont95tal ,europe &1 h5ce1 call$ ! ,cont95tal ,code4 ,x is n[ us$ = all g5]al public s]vice wireless communication all ov] ! _w &1 h5ce1 x is call$ ! ,int]national ,code4 ,see page #cje ,app5dix3 ,int]national ,morse ,code4 ,,alt]nat+ ,,curr5t 7,a4,c47--,see ,curr5t4 ,,alt]nat+ ,,curr5t ,,trans=m]4--,see ,trans=m]4 ,,amateur ,,gr\nd4--,see ,gr\nd1 ,amateur4 ,,ammet]4--,an in/rum5t us$ = measur+ ! curr5t /r5g?1 9 t]ms ( amp]es1 t fl[s 9 a circuit4 ,ammet]s us$ = measur+ direct & alt]nat+ curr5ts make use ( ! magnetic effects ( ! curr5ts4 ,high frequ5cy curr5ts make use ( ! heat+ effects ( ! curr5ts4 ,,ammet]1 ,,hot-,,wire4--,high frequ5cy curr5ts are usually measur$ by means ( an in/rum5t :i* dep5ds on heat+ a wire or metal /rip by ! oscillations4 ,su* an in/rum5t is (t5 call$ a !rmal ammet]1 radio ammet] & a]ial ammet]4 ,,ammet]1 ,,a]ial4--,see ,ammet]1 ,hot ,wire4 ,,ammet]1 ,,radio4--,see ,ammet]1 ,hot ,wire4 ,,amp]e4--,! curr5t :i* :5 pass$ ?r\gh a solution ( nitrate ( silv] 9 wat] accord+ to c]ta9 specifications1 deposits silv] at ! rate ( #j4jjaaahjj ( a gram p] second4 ,,amp]e-,,h\r4--,! quantity ( electricity transf]r$ by a curr5t ( #a amp]e 9 #a h\r & is1 !re=e1 equal to #cfjj c\lombs4 ,,amp]e-,,turns4--,:5 a coil is w\nd up ) a numb] ( turns ( wire & a curr5t is made to fl[ ?r\gh x1 x behaves l a magnet4 ,b ,! /r5g? ( ! magnetic field inside ( ! coil dep5ds on 7#a7 ! /r5g? ( ! curr5t & 7#b7 ! numb] ( turns ( wire on ! coil4 ,?us a feeble curr5t fl[+ ?r\gh a l>ge numb] ( turns w produce z /rong a magnetic field z a /rong curr5t fl[+ ?r\gh a few turns ( wire4 ,?is product ( ! curr5t 9 amp]es times ! numb] ( turns ( wire on ! coil is call$ ! amp]e-turns4 ,,amplification1 ,,audio ,,frequ5cy4--,a curr5t ( audio frequ5cy t is amplifi$ by an amplifi] tube or o!r means4 ,,amplification1 ,,cascade4--,see ,cascade ,amplification4 ,,amplification1 ,,radio ,,frequ5cy4--,a curr5t ( radio frequ5cy t is amplifi$ by an amplifi] tube or o!r means be=e x rea*es ! detector4 ,,amplification1 ,,reg5]ative4--,a s*eme t uses a ?ird circuit to fe$ back "p ( ! oscillations ?r\gh a vacuum tube & :i* increases its s5sitiv5ess :5 us$ z a detector & multiplies its action z an amplifi] & an oscillator4 ,,amplifi]1 ,,audio ,,frequ5cy4--,a vacuum tube or o!r device t amplifies ! signals aft] pass+ ?r\gh ! detector4 ,,amplifi]1 ,,magnetic4--,a device us$ = controll+ radio frequ5cy curr5ts ei!r by means ( a telegraph key or a microphone transmitt]4 ,! controll+ curr5t fl[s ?r\gh a sep>ate circuit f t ( ! radio curr5t & a fraction ( an amp]e w control sev]al amp]es 9 ! a]ial wire4 ,,amplifi]s1 ,,multi-,,/age4--,a receiv+ set us+ two or m amplifi]s4 ,also call$ cascade amplification4 ,,amplifi]1 ,,vacuum ,,tube4--,a vacuum tube t is us$ ei!r to amplify ! radio frequ5cy curr5ts or ! audio frequ5cy curr5ts4 ,,amplitude ,,( ,,wave4--,! greate/ di/ance t a po9t moves f its position ( re/4 ,,amplify+ ,,trans=m]1 ,,audio4--,see ,trans=m]1 ,audio ,amplify+4 ,,amplify+ ,,modulator ,,vacuum ,,tube4--,see ,vacuum ,tube1 ,amplify+ ,modulator4 ,,amplify+ ,,trans=m] ,,radio4--,see ,trans=m]1 ,radio ,amplify+4 ,,ant5na1 ,,amateur4--,see ,a]ial1 ,amateur4 ,,ant5na ,,swit*4--,see ,swit*1 ,a]ial4 ,,app>atus ,,symbols4--,see ,symbols1 ,app>atus4 ,,arm/rong ,,circuit4--,see ,circuit1 ,arm/rong4 ,,atmosph]ics4--,same z ,/atic1 :i* see4 ,,att5uation4--,9 ,s5d+ wireless telegraph & telephone messages ! amplitude ( ! electric waves is damp$ out z ! di/ance increases4 ,?is is call$ att5uation & x increases z ! frequ5cy is increas$4 ,?is is ! reason :y %ort wave l5g?s w n c>ry z f> z long wave l5g?s4 ,,audio ,,frequ5cy ,,amplifi]4--,see ,amplifi]1 ,audio ,frequ5cy4 ,,audio ,,frequ5cy ,,amplification4--,see ,amplification1 ,audio ,frequ5cy4 ,,audibility ,,met]4--,see ,met]1 ,audibility4 ,,audio ,,frequ5cy4--,see ,frequ5cy1 ,audio4 ,,audio ,,frequ5cy ,,curr5t4--,see ,curr5t1 ,audio ,frequ5cy4 ,,audion4--,an e>ly trade "n giv5 to ! vacuum tube detector4 ,,autodyne ,,receptor4--,see ,receptor1 ,autodyne4 ,,auto ,,trans=m]4--,see ,trans=m]1 ,auto4 ,,bakelite4--,a manufactur$ insulat+ comp\nd4 ,b ,,batt]y4--,see ,batt]y ,b4 ,,b&1 ,,wave ,,l5g?4--,see ,wave ,l5g? ,b&4 ,,basket ,,w\nd ,,coils4--,see ,coils1 ,inductance4 ,,batt]y1 ,a4--,! #f-volt /orage batt]y us$ to heat ! filam5t ( a vacuum tube1 detector or amplifi]4 ,,batt]y1 ,b4--,! #bb-a_/b-volt dry cell batt]y us$ to en]gize ! plate ( a vacuum tube detector or amplifi]4 ,,batt]y1 ,,boo/]4--,?is is ! batt]y t is connect$ 9 s]ies ) ! cry/al detector4 ,,batt]y1 ,c4--,a small dry cell batt]y sometimes us$ to give ! grid ( a vacuum tube detector a bias pot5tial4 ,,batt]y1 ,,edison ,,/orage4--,a /orage batt]y 9 :i* ! elem5ts are made ( nickel & iron & imm]s$ 9 an alkal9e electrolyte4 ,,batt]y1 ,,lead ,,/orage4--,a /orage batt]y 9 :i* ! elem5ts are made ( lead & imm]s$ 9 an acid electrolyte4 ,,batt]y ,,poles4--,see ,poles1 ,batt]y4 ,,batt]y1 ,,prim>y4--,a batt]y t g5]ates curr5t by *emical action4 ,,batt]y1 ,,/orage4--,a batt]y t develops a curr5t aft] x has be5 *>g$4 ,,beat ,,reception4--,see ,het]odyne ,reception4 ,,b$ ,,spr+s ,,a]ial4--,see ,a]ial1 ,b$ ,spr+s4 ,,blub ,,blub4--,ov] modulation 9 wireless telephony4 ,,broad ,,wave4--,see ,wave1 ,broad4 ,,bru% ,,dis*>ge4--,see ,dis*>ge4 ,,buzz] ,,modulation4--,see ,modulation1 ,buzz]4 ,,blue ,,gl[ ,,dis*>ge4--,see ,dis*>ge4 ,,boo/] ,,batt]y4--,see ,batt]y1 ,boo/]4 ,,broadca/+4--,s5d+ out intellig5ce & music f a c5tral /ation = ! b5efit ( all :o live )9 range ( x & :o h receiv+ sets4 ,,capacitance4--,also call$ by ! old] "n ( capacity4 ,! capacity ( a cond5s]1 inductance coil or o!r device capable ( reta9+ a *>ge ( electricity4 ,capacitance is measur$ 9 t]ms ( ! micr(>ad4 ,,capacitive ,,c\pl+4--,see ,c\pl+1 ,capacitive4 ,,capacity4--,any object t w reta9 a *>ge ( electricity2 h5ce an a]ial wire1 a cond5s] or a metal plate is sometimes call$ a capacity4 ,,capacity1 ,,a]ial4--,! am\nt to :i* an a]ial wire sy/em c be *>g$4 ,! capacitance ( a small amateur a]ial is f #j4jjjb to #j4jjje micr(>ad4 ,,capacity1 ,,di/ribut$4--,a coil ( wire n only has inductance1 b also a c]ta9 small capacitance4 ,coils w\nd ) _! turns p>allel & hav+ a numb] ( lay]s h a bun*$ capacitance :i* produces unt[>d effects 9 oscillation circuits4 ,9 honeycomb & o!r /agg] w\nd coils ! capacitance is m ev5ly di/ribut$4 ,,capacity ,,reactance4--,see ,reactance1 ,capacity4 ,,capacity ,,unit4--,see ,f>ad4 ,,c>bon ,,rheo/ats4--,see ,rheo/at1 ,c>bon4 ,,c>borundum ,,detector4--,see ,detector4 ,,c>ri] ,,curr5t ,,telephony4--,see ,wir$-,wireless4 ,,c>ri] ,,frequ5cy4--,see ,frequ5cy1 ,c>ri]4 ,,c>ri] ,,frequ5cy ,,telephony4--,see ,wir$-,wireless4 ,,cascade ,,amplification4--,two or m amplify+ tubes hook$ up 9 a receiv+ set4 ,,cat ,,:isk] ,,contact4--,a long1 ?9 wire :i* makes contact ) ! cry/al ( a detector4 ,,c5timet] ,,( ,,capacitance4--,equal to #a4aa micr(>ads4 ,,c5timet] ,,( ,,inductance4--,equal to "o "o-?\s&? "p ( a microh5ry4 ,,cellul> ,,coils4--,see ,coils1 ,inductance4 ,c4,g4,s4 ,,electro/atic ,,unit ,,( ,,capacitance4--,see ,c5timet] ( ,capacitance4 ,,*>act]i/ics4--,! special behavior ( a device1 su* z an a]ial1 a detector tube1 etc4 ,,*>act]i/ics1 ,,grid4--,see ,grid ,*>act]i/ics4 ,,*oke ,,coils4--,coils t prev5t ! high voltage oscillations f surg+ back into ! trans=m] & break+ d[n ! insulation4 ,,*opp] ,,modulation4--,see ,modulation1 ,*opp]4 ,,circuit4--,any electrical conductor ?r\gh :i* a curr5t c fl[4 ,a l[ voltage curr5t requires a loop ( wire or o!r conductor bo? ends ( :i* are connect$ to ! s\rce ( curr5t be=e x c fl[4 ,a high frequ5cy curr5t w surge 9 a wire :i* is op5 at bo? ends l ! a]ial4 ,clos$ ,circuit4--,a circuit t is cont9u\s4 ,op5 ,circuit4--,a conductor t is n cont9u\s4 ,c\pl$ ,circuits4--,op5 & clos$ circuits connect$ toge!r by inductance coils1 cond5s]s or resi/ances4 ,see c\pl+4 ,close ,c\pl$ ,circuits4--,op5 & clos$ circuits connect$ directly toge!r ) a s+le inductance coil4 ,loose ,c\pl$ ,circuits4--,op5$ & clos$ curr5ts connect$ toge!r inductively by means ( a trans=m]4 ,/&-by ,circuits4--,also call$ pick-up circuits4 ,:5 li/5+-9 = possible calls f a numb] ( /ations1 a receiv] is us$ :i* w respond to a wide b& ( wave l5g?s4 ,arm/rong ,circuits4--,! reg5]ative circuit inv5t$ by ,major ,e4 ,h4 ,arm/rong4 ,,close ,,c\pl$ ,,circuits4--,see ,curr5ts1 ,close ,c\pl$4 ,,clos$ ,,circuit4--,see ,circuit1 ,clos$4 ,,clos$ ,,core ,,trans=m]4--,see ,trans=m]1 ,clos$ ,core4 ,,code4-- ,cont95tal4--,same z ,int]national4 ,int]national4--,on ! cont95t ( ,europe l& l9es use ! ,cont95tal ,morse alphabetic code4 ,?is code has come to be us$ ?r\gh\t ! _w = wireless telegraphy & h5ce x is n[ call$ ! ,int]national code4 ,x is giv5 on ,page #cje4 ,app5dix3 ,int]national ,morse ,code4 ,morse4--,! code devis$ by ,samuel ,f4 ,b4 ,morse & :i* is us$ on ! l& l9es 9 ! ,u4 ,s4 ,national ,electric4--,a set ( rules & requirem5ts devis$ by ! ,national ,bo>d ( ,fire ,und]writ]s = ! electrical in/allations 9 build+s on :i* insurance companies c>ry risks4 ,?is code also cov]s ! requirem5ts = wireless in/allations4 ,a copy may be _h f ! ,national ,bo>d ( ,fire ,und]writ]s1 ,new ,york ,city1 or f y\r insurance ag5t4 ,national ,electric ,safety4--,! ,bureau ( ,/&>ds1 ,wa%+ton1 ,d4 ,c41 h inve/igat$ ! precautions :i* %\ld be tak5 = ! safe op]ation ( all electric equipm5t4 ,a copy ( ! ,bureau ( ,/&>ds ,h&book ,no4 #c c be _h = #dj c5ts f ! ,sup]9t5d5t ( ,docum5ts4 ,,coeffici5t ,,( ,,c\pl+4--,see ,c\pl+1 ,coeffici5t (4 ,,coil ,,a]ial4--,see ,a]ial1 ,loop4 ,,coil ,,ant5na4--,see ,a]ial1 ,loop4 ,,coil1 ,,induction4--,an app>atus = *ang+ l[ voltage direct curr5ts into high voltage1 l[ frequ5cy alt]nat+ curr5ts4 ,:5 fitt$ ) a sp>k gap ! high voltage1 l[ frequ5cy curr5ts are conv]t$ into high voltage1 high frequ5cy curr5ts4 ,x is !n also call$ a sp>k coil & a ,ruhmkorff coil4 ,,coil1 ,,load+4--,a coil connect$ 9 ! a]ial or clos$ oscillation circuit s t long] wave l5g?s c be receiv$4 ,,coil1 ,,repeat+4--,see ,repeat+ ,coil4 ,,coil1 ,,rotat+4--,"o :i* rotates on a %aft in/ead ( slid+ z 9 a loose c\pl]4 ,! rotor ( a v>iomet] or v>ioc\pl] is a rotat+ coil4 ,,coils1 ,,inductance4--,^! are ! tun+ coils us$ = s5d+ & receiv+ sets4 ,= s5d+ sets !y are =m$ ( "o & two coils1 a s+le s5d+ coil is g5]ally call$ a tun+ inductance coil1 :ile a two-coil tun] is call$ an oscillation trans=m]4 ,receiv+ tun+ coils are made ) a s+le lay]1 s+le coil1 or a pair ( coils1 :5 x is call$ an oscillation trans=m]4 ,"s tun+ inductance coils h m ?an "o lay]1 !y are !n call$ lattice w\nd1 cellul>1 basket w\nd1 honeycomb1 duo-lat]al1 /agg] w\nd1 spid]-web & slab coils4 ,,comm]cial ,,frequ5cy4--,see ,frequ5cy1 ,comm]cial4 ,,cond5s]1 ,,a]ial ,,s]ies4--,a cond5s] plac$ 9 ! a]ial wire sy/em to cut d[n ! wave l5g?4 ,,cond5s]1 ,,v]ni]4--,a small v>iable cond5s] us$ = receiv+ cont9u\s waves :]e v %>p tun+ is desir$4 ,,cond5s]4--,all conduct+ objects ) _! insulation =m capacities1 b a cond5s] is und]/ood to mean two %eets or plates ( metal plac$ closely toge!r b sep>at$ by "s insulat+ mat]ial4 ,adju/able ,cond5s]4--,:]e two or m cond5s]s c be c\pl$ toge!r by means ( plugs1 swit*es or o!r devices4 ,a]ial ,cond5s]4--,a cond5s] connect$ 9 ! a]ial4 ,air ,cond5s]4--,:]e air only sep>ates ! %eets ( metal4 ,by-,pass ,cond5s]4--,a cond5s] connect$ 9 ! transmitt+ curr5ts s t ! high frequ5cy curr5ts _c fl[ back ?r\gh ! p[] circuit4 ,filt] ,cond5s]4--,a cond5s] ( l>ge capacitance us$ 9 comb9ation ) a filt] reactor = smoo?+ out ! pulsat+ direct curr5ts z !y come f ! rectifi]4 ,fix$ ,cond5s]4--,:]e ! plates are fix$ relatively to "o ano!r4 ,grid ,cond5s]4--,a cond5s] connect$ 9 s]ies ) ! grid lead4 ,leyd5 ,j> ,cond5s]4--,:]e glass j>s are us$4 ,mica ,cond5s]4--,:]e mica is us$4 ,oil ,cond5s]4--,:]e ! plates are imm]s$ 9 oil4 ,pap] ,cond5s]4--,:]e pap] is us$ z ! insulat+ mat]ial4 ,protective4--,a cond5s] ( l>ge capacity connect$ across ! l[ voltage supply circuit ( a transmitt] to =m a by-pa? ( kick-back oscillations4 ,v>iable ,cond5s]4--,:]e alt]nate plates c be mov$ & s made to int]leave m or less ) a set ( fix$ plates4 ,v]ni]4--,a small cond5s] ) a v]ni] on x s t x c be v accurately v>i$4 ,x is connect$ 9 p>allel ) ! v>iable cond5s] us$ 9 ! prim>y circuit & is us$ = ! reception ( cont9u\s waves :]e %>p tun+ is ess5tial4 ,,cond5site4--,a manufactur$ insulat+ comp\nd4 ,,conductivity4--,! conductance ( a giv5 l5g? ( wire ( uni=m cross section4 ,! reciprocal ( resi/ivity4 ,,contact ,,detectors4--,see ,detectors1 ,contact4 ,,cont95tal ,,code4--,see ,code1 ,cont95tal4 ,,c\lomb4--,! quantity ( electricity transf]r$ by a curr5t ( #a amp]e 9 #a second4 ,,convective ,,dis*>ge4--,see ,dis*>ge4 ,,conv5tional ,,signals4--,see ,signals1 ,conv5tional4 ,,c\nt] ,,electromotive ,,=ce4--,see ,electromotive ,=ce1 ,c\nt]4 ,,c\nt]poise4 ,a duplicate ( ! a]ial wire t is rais$ a few feet above ! e>? & insulat$ f x4 ,usually no connection is made ) ! e>? itself4 ,,c\pl$ ,,circuits4--,see ,circuit1 ,c\pl$4 ,,c\pl+4--,:5 two oscillation circuits are connect$ toge!r ei!r by ! magnetic field ( an inductance coil1 or by ! electro/atic field ( a cond5s]4 ,,c\pl+1 ,,capacitive4--,oscillation circuits :5 connect$ toge!r by cond5s]s in/ead ( inductance coils4 ,,c\pl+1 ,,coeffici5t ,,(4--,! measure ( ! clos5ess ( ! c\pl+ betwe5 two coils4 ,,c\pl+1 ,,inductive4--,oscillation circuits :5 connect$ toge!r by inductance coils4 ,,c\pl+1 ,,resi/ance4--,oscillation circuits connect$ toge!r by a resi/ance4 ,,cry/al ,,rectifi]4--,a cry/al detector4 ,,curr5t1 ,,alt]nat+ 7,a4,c474--,a l[ frequ5cy curr5t t surges to & fro 9 a circuit4 ,,curr5t1 ,,audio ,,frequ5cy4--,a curr5t ^: frequ5cy is l[ en\gh to be he>d 9 a telephone receiv]4 ,su* a curr5t usually has a frequ5cy ( betwe5 #bjj & #b1jjj cycles p] second4 ,,curr5t1 ,,plate4--,! curr5t :i* fl[s betwe5 ! filam5t & ! plate ( a vacuum tube4 ,,curr5t1 ,,pulsat+4--,a direct curr5t ^: voltage v>ies f mom5t to mom5t4 ,,curr5t1 ,,radio ,,frequ5cy4--,a curr5t ^: frequ5cy is s high x _c be he>d 9 a telephone receiv]4 ,su* a curr5t may h a frequ5cy ( f #bj1jjj to #aj1jjj1jjj p] second4 ,,curr5ts1 ,,high ,,frequ5cy4--7#a7 ,curr5ts t oscillate f #aj1jjj to #cjj1jjj1jjj times p] second4 7#b7 ,electric oscillations4 ,,curr5ts1 ,,high ,,pot5tial4--7#a7 ,curr5ts t h a pot5tial ( m ?an #aj1jjj volts4 7#b7 ,high voltage curr5ts4 ,,cycle4--7#a7 ,a s]ies ( *anges :i* :5 complet$ are aga9 at ! />t+ po9t4 7#b7 ,a p]iod ( "t at ! end ( :i* an alt]nat+ or oscillat+ curr5t repeats its orig9al direction ( fl[4 ,,damp+4--,! degree to :i* ! en]gy ( an electric oscillation is r$uc$4 ,9 an op5 circuit ! en]gy ( an oscillation set up by a sp>k gap is damp$ out 9 a few sw+s1 :ile 9 a clos$ circuit x is greatly prolong$1 ! curr5t oscillat+ #bj times or m be=e ! en]gy is dissipat$ by ! sum ( ! resi/ances ( ! circuit4 ,,decrem5t4--,! act or process ( gradually becom+ less4 ,,detector4--,any device t w 7#a7 *ange ! oscillations set up by ! incom+ waves into direct curr5t1 t is :i* w rectify !m1 or 7#b7 t w act z a relay4 ,c>borundum4--,"o t uses a c>borundum cry/al = ! s5sitive elem5t4 ,c>borundum is a cry/all9e silicon c>bide =m$ 9 ! electric furnace4 ,cat ,:isk] ,contact4--,see ,cat ,:isk] ,contact4 ,*alcopyrite4--,copp] pyrites4 ,a brass color$ m9]al us$ z a cry/al = detectors4 ,see ,z9cite4 ,contact4--,a cry/al detector4 ,any k9d ( a detector 9 :i* two dissimil> b suitable solids make contact4 ,f]ron4--,a detector 9 :i* iron pyrites are us$ z ! s5sitive elem5t4 ,gal5a4--,a detector t uses a gal5a cry/al = ! rectify+ elem5t4 ,iron ,pyrites4--,a detector t uses a cry/al ( iron pyrites = its s5sitive elem5t4 ,molybd5ite4--,a detector t uses a cry/al ( sulphide ( molybd5um = ! s5sitive elem5t4 ,p]ikon4--,a detector 9 :i* a bornite cry/al makes contact ) a z9cite cry/al4 ,silicon4--,a detector t uses a cry/al ( silicon = its s5sitive elem5t4 ,vacuum ,tube4--,a vacuum tube 7:i* see7 us$ z a detector4 ,z9cite4--,a detector 9 :i* a cry/al ( z9cite is us$ z ! s5sitive elem5t4 ,,de ,,tun+4--,a me?od ( signal+ by su/a9$ oscillations 9 :i* ! key :5 press$ d[n cuts out ei!r "s ( ! inductance or "s ( ! capacity & h5ce greatly *anges ! wave l5g?4 ,,dielectric4--,an insulat+ mat]ial betwe5 two electrically *>g$ plates 9 :i* !re is set up an electric /ra91 or displacem5t4 ,,dielectric ,,/ra94--,! electric displacem5t 9 a dielectric4 ,,directional ,,a]ial4--,see ,a]ial1 ,directional4 ,,direction ,,f9d]4--,see ,a]ial1 ,loop4 ,,dis*>ge4--7#a7 ,a fa9tly lum9\s dis*>ge t takes place f ! positive po9t$ t]m9al ( an induction coil1 or o!r high pot5tial app>atus2 is t]m$ a bru% dis*>ge4 7#b7 ,a cont9u\s dis*>ge betwe5 ! t]m9als ( a high pot5tial app>atus is t]m$ a convective dis*>ge4 7#c7 ,! sudd5 break+-d[n ( ! air betwe5 ! balls =m+ ! sp>k gap is t]m$ a disruptive dis*>ge2 also call$ an electric sp>k1 or j sp>k = %ort4 7#d7 ,:5 a tube has a poor vacuum1 or too l>ge a batt]y voltage1 x gl[s ) a blue light & ?is is call$ a blue gl[ dis*>ge4 ,,disruptive ,,dis*>ge4--,see ,dis*>ge4 ,,di/ress ,,call4 ,morse code3 444---444 7,,sos74 ,,di/ribut$ ,,capacity4--,see ,capacity1 ,di/ribut$4 ,,d\ble ,,hump ,,resonance ,,curve4--,a resonance curve t has two peaks or humps :i* %[ t ! oscillat+ curr5ts :i* are set up :5 ! prim>y & second>y ( a tun+ coil are closely c\pl$ h two frequ5cies4 ,,duo-,,lat]al ,,coils4--,see ,coils1 ,inductance4 ,,duplex ,,communication4--,a wireless telephone sy/em ) :i* x is possible to talk betwe5 bo? /ations 9 ei!r direction )\t ! use ( swit*es4 ,?is is kn[n z ! duplex sy/em4 ,,e>? ,,capacity4--,an a]ial c\nt]poise4 ,,e>? ,,connection4--,metal plates or wires buri$ 9 ! gr\nd or imm]s$ 9 wat]4 ,any k9d ( means by :i* ! s5d+ & receiv+ app>atus c be connect$ ) ! e>?4 ,,edison ,,/orage ,,batt]y4--,see ,/orage ,batt]y1 ,edison4 ,,electric ,,en]gy4--,! p[] ( an electric curr5t4 ,,electric ,,oscillations4--,see ,oscillations1 ,electric4 ,,electric ,,sp>k4--,see ,dis*>ge1 ,sp>k4 ,,electricity1 ,,negative4--,! opposite ( positive electricity4 ,negative electricity is =m$ ( negative electrons :i* make up ! outside p>ticles ( an atom4 ,,electricity1 ,,positive4--,! opposite ( negative electricity4 ,positive electricity is =m$ ( positive electrons :i* make up ! inside p>ticles ( an atom4 ,,electrodes4--,usually ! p>ts ( an app>atus :i* dip into a liquid & c>ry a curr5t4 ,! electrodes ( a dry batt]y are ! z9c & c>bon elem5ts4 ,! electrodes ( an ,edison /orage batt]y are ! iron & nickel elem5ts1 & ! electrodes ( a lead /orage batt]y are ! lead elem5ts4 ,,electrolytes4--,! acid or alkal9e solutions us$ 9 batt]ies4 ,,electromagnetic ,,waves4--,see ,waves1 ,electric4 ,,electromotive ,,=ce4--,abbreviat$ emf4 ,! =ce t drives an electric curr5t along a conductor4 ,also loosely call$ voltage4 ,,electromotive ,,=ce1 ,,c\nt]4--,! emf4 t is set up 9 a direction opposite to t 9 :i* ! curr5t is fl[+ 9 a conductor4 ,,electron4--7#a7 ,a negative p>ticle ( electricity t is deta*$ f an atom4 7#b7 ,a negative p>ticle ( electricity ?r[n (f f ! inc&esc5t filam5t ( a vacuum tube4 ,,electron ,,fl[4--,! passage ( electrons betwe5 ! inc&esc5t filam5t & ! cold positively *>g$ plate ( a vacuum tube4 ,,electron ,,relay4--,see ,relay1 ,electron4 ,,electron ,,tube4--,a vacuum tube or a gas-cont5t tube us$ = any purpose 9 wireless "w4 ,see ,vacuum ,tube4 ,,electrose ,,insulators4--,insulators made ( a composition mat]ial ! trade "n ( :i* is ,electrose4 ,,en]gy1 ,,electric4--,see ,electric ,en]gy4 ,,en]gy ,,unit4--,! j\le1 :i* see1 ,page #cjh ,app5dix3 ,def9itions ( ,electric & ,magnetic ,units4 ,,fad+4--,! sudd5 v>iation 9 /r5g? ( signals receiv$ f a transmitt+ /ation :5 all ! adju/m5ts ( bo? s5d+ & receiv+ app>atus rema9 ! same4 ,also call$ sw++4 ,,f>ad4--,! capacitance ( a cond5s] 9 :i* a pot5tial diff]5ce ( #a volt causes x to h a *>ge ( #a c\lomb ( electricity4 ,,fe$-,,back ,,action4--,fe$+ back ! oscillat+ curr5ts 9 a vacuum tube to amplify its p[]4 ,also call$ reg5]ative action4 ,,f]romagnetic ,,control4--,see ,magnetic ,amplifi]4 ,,filam5t4--,! wire 9 a vacuum tube t is heat$ to inc&esc5ce & :i* ?r[s (f electrons4 ,,filam5t ,,rheo/at4--,see ,rheo/at1 ,filam5t4 ,,filt]4--,inductance coils or cond5s]s or bo? :i* 7#a7 prev5t tr\blesome voltages f act+ on ! diff]5t circuits1 & 7#b7 smoo? out alt]nat+ curr5ts aft] !y h be5 rectifi$4 ,,filt] ,,reactor4--,see ,reactor1 ,filt]4 ,,fire ,,und]writ]s4--,see ,code1 ,national ,electric4 ,,fix$ ,,gap4--,see ,gap4 ,,flem+ ,,valve4--,a two-electrode vacuum tube4 ,,=c$ ,,oscillations4--,see ,oscillations1 ,=c$4 ,,free ,,oscillations4--,see ,oscillations1 ,free4 ,,frequ5cy1 ,,audio4--7#a7 ,an alt]nat+ curr5t ^: frequ5cy is l[ en\gh to op]ate a telephone receiv] &1 h5ce1 :i* c be he>d by ! e>4 7#b7 ,audio frequ5cies are usually ar\nd #ejj or #a1jjj cycles p] second1 b may be z l[ z #bjj & z high z #aj1jjj cycles p] second4 ,c>ri]4--,a radio frequ5cy wave modulat$ by an audio frequ5cy wave :i* results 9 sett+ ( ?ree radio frequ5cy waves4 ,! pr9cipal radio frequ5cy is call$ ! c>ri] frequ5cy1 s9ce x c>ries or transmits ! audio frequ5cy wave4 ,comm]cial4--7#a7 ,alt]nat+ curr5t t is us$ = comm]cial purposes1 namely1 light1 heat & p[]4 7#b7 ,comm]cial frequ5cies n[ 9 g5]al use are f #be to #ej cycles p] second4 ,natural4--,! p5dulum & vibrat+ spr+ h a natural frequ5cy :i* dep5ds on ! size1 mat]ial ( :i* x is made1 & ! friction :i* x has to ov]come4 ,likewise an oscillation circuit has a natural frequ5cy :i* dep5ds ^u its inductance1 capacitance & resi/ance4 ,radio4--7#a7 ,an oscillat+ curr5t ^: frequ5cy is too high to affect a telephone receiv] &1 h5ce1 _c be he>d by ! e>4 7#b7 ,radio frequ5cies are usually betwe5 #bj1jjj & #b1jjj1jjj cycles p] second b may be z l[ z #aj1jjj & z high z #cjj1jjj1jjj cycles p] second4 ,sp>k4--,! numb] ( sp>ks p] second produc$ by ! dis*>ge ( a cond5s]4 ,,gap1 ,,fix$4--,"o ) fix$ electrodes4 ,,gap1 ,,non-,,syn*ron\s4--,a rot>y sp>k gap run by a sep>ate motor :i* may be widely diff]5t f t ( ! spe$ ( ! alt]nator4 ,,gap1 ,,qu5*$4--7#a7 ,a sp>k gap = ! impulse production ( oscillat+ curr5ts4 7#b7 ,?is me?od c be lik5$ to "o :]e a spr+ is /ruck a s+le %>p bl[ & !n cont9ues to set up vibrations4 ,,gap1 ,,rot>y4--,"o hav+ fix$ & rotat+ electrodes4 ,,gap1 ,,syn*ron\s4--,a rot>y sp>k gap run at ! same spe$ z ! alt]nator :i* supplies ! p[] trans=m]4 ,su* a gap usually has z _m tee? z !re are poles on ! g5]ator4 ,h5ce "o sp>k occurs p] half cycle4 ,,gas-,,cont5t ,,tube4--,see ,vacuum ,tube4 ,,g5]ator ,,tube4--,a vacuum tube us$ to set up oscillations4 ,z a matt] ( fact x does n g5]ate oscillations1 b *anges ! initial l[ voltage curr5t t fl[s ?r\gh x into oscillations4 ,also call$ an oscillator tube & a p[] tube4 ,,grid ,,batt]y4--,see ,batt]y ,c4 ,,grid ,,*>act]i/ics4--,! v>i\s relations t c\ld exi/ betwe5 ! voltages & curr5ts ( ! grid ( a vacuum tube1 & ! values :i* d exi/ betwe5 !m :5 ! tube is 9 op]ation4 ,^! *>act]i/ics are g5]ally %[n by curves4 ,,grid ,,cond5s]4--,see ,cond5s]1 ,grid4 ,,grid ,,leak4--,a high resi/ance unit connect$ 9 ! grid lead ( bo? s5d+ & receiv+ sets4 ,9 a s5d+ set x keeps ! voltage ( ! grid at a con/ant value & s controls ! output ( ! a]ial4 ,9 a receiv+ set x controls ! curr5t fl[+ betwe5 ! plate & filam5t4 ,,grid ,,modulation4--,see ,modulation1 ,grid4 ,,grid ,,pot5tial4--,! negative or positive voltage ( ! grid ( a vacuum tube4 ,,grid ,,voltage4--,see ,grid ,pot5tial4 ,,gr9d]s4--,! mo/ common =m ( ,/atic1 :i* see4 ,!y make a gr9d+ noise 9 ! headphones4 ,,gr\nd4--,see ,e>? ,connection4 ,,gr\nd1 ,,amateur4--,a wat]-pipe gr\nd4 ,,gr\nd1 ,,wat]pipe4--,a common me?od ( gr\nd+ by amateurs is to use ! wat]pipe1 gaspipe or radiator4 ,,guid$ ,,wave ,,telephony4--,see ,wir$ ,wireless4 ,,h>d ,,tube4--,a vacuum tube 9 :i* ! vacuum is high1 t is1 exhau/$ to a high degree4 ,,helix4--7#a7 ,any coil ( wire4 7#b7 ,specifically a transmitt] tun+ inductance coil4 ,,h5ry4--,! inductance 9 a circuit 9 :i* ! electromotive =ce induc$ is #a volt :5 ! induc+ curr5t v>ies at ! rate ( #a amp]e p] second4 ,,het]odyne ,,reception4--7#a7 ,receiv+ by ! beat me?od4 7#b7 ,receiv+ by means ( sup]pos+ oscillations g5]at$ at ! receiv+ /ation on ! oscillations set up 9 ! a]ial by ! incom+ waves4 ,,het]odyne ,,receptor4--,see ,receptor1 ,het]odyne4 ,,high ,,frequ5cy ,,curr5ts4--,see ,curr5ts1 ,high ,frequ5cy4 ,,high ,,frequ5cy ,,resi/ance4--,see ,resi/ance1 ,high ,frequ5cy4 ,,high ,,pot5tial ,,curr5ts4--,see ,curr5ts1 ,high ,pot5tial4 ,,high ,,voltage ,,curr5ts4--,see ,curr5ts1 ,high ,pot5tial4 ,,honeycomb ,,coils4--,see ,coils1 ,inductance4 ,,horse-,,p[]4--,us$ 9 rat+ /eam ma*9]y4 ,x is equal to #gdf watts4 ,,hot ,,wire ,,ammet]4--,see ,ammet]1 ,hot ,wire4 ,,h[l+4--,:]e m ?an ?ree /ages ( radio amplification1 or m ?an two /ages ( audio amplification1 are us$ h[l+ noises are apt to occur 9 ! telephone receiv]s4 ,,imp$ance4--,an oscillation circuit has reactance & also resi/ance1 & :5 ^! are comb9$ ! total opposition to ! curr5t is call$ imp$ance4 ,,inductance ,,coils4--,see ,coils1 ,inductance4 ,,inductance ,,coil1 ,,load+4--,see ,coil1 ,load+ ,inductance4 ,,inductive ,,c\pl+4--,see ,c\pl+1 ,inductive4 ,,inductive ,,reactance4--,see ,reactance1 ,inductive4 ,,induction ,,coil4--,see ,coil1 ,induction4 ,,induction1 ,,mutual4--,induction produc$ betwe5 two circuits or coils close to ea* o!r by ! mutual int]action ( _! magnetic fields4 ,,insulation4--,mat]ials us$ on & ar\nd wires & o!r conductors to keep ! curr5t f leak+ away4 ,,inspector1 ,,radio4--,a ,u4 ,s4 inspector ^: bus9ess x is to issue bo? /ation & op]ators' lic5ses 9 ! di/rict ( :i* he is 9 *>ge4 ,,int]f]5ce4--,! cross+ or sup]pos+ ( two sets ( electric waves ( ! same or slightly diff]5t l5g?s :i* t5d to oppose ea* o!r4 ,x is ! unt[>d int]f]5ce betwe5 electric waves f diff]5t /ations t makes selective signal+ s difficult a problem4 ,,int]m$iate ,,waves4--,see ,waves4 ,,ionic ,,tubes4--,see ,vacuum ,tubes4 ,,int]national ,,code4--,see ,code1 ,int]national4 ,,jamm+4--,waves t are ( su* l5g? & /r5g? t :5 !y int]f]e ) incom+ waves !y dr[n !m out4 ,,j\le4--,! en]gy sp5t 9 #a second by a fl[ ( #a amp]e 9 #a ohm4 ,,j\le',s ,,law4--,! relation betwe5 ! heat produc$ 9 seconds to ! resi/ance ( ! circuit1 to ! curr5t fl[+ 9 x4 ,,k5otron4--,! trade "n ( a vacuum tube rectifi] made by ! ,radio ,corporation ( ,am]ica4 ,,kick-,,back4--,oscillat+ curr5ts t rise 9 voltage & t5d to fl[ back ?r\gh ! circuit t is supply+ ! transmitt] ) l[ voltage curr5t4 ,,kick-,,back ,,prev5tion4--,see ,prev5tion1 ,kick-,back4 ,,kil[att4--#a1jjj watts4 ,,lambda4--,see ,pages #cja1 #cjb4 ,app5dix3 ,useful ,abbreviations4 ,,lattice ,,w\nd ,,coils4--,see ,coils1 ,inductance4 ,,lightn+ ,,swit*4--,see ,swit*1 ,lightn+4 ,,l9e ,,radio ,,communication4--,see ,wir$ ,wireless4 ,,l9e ,,radio ,,telephony4--,see ,telephony1 ,l9e ,radio4 ,,litz5draht4--,a conductor =m$ ( a numb] ( f9e copp] wires ei!r twi/$ or braid$ toge!r4 ,x is us$ to r$uce ! sk9 effect4 ,see ,resi/ance1 ,high ,frequ5cy4 ,,load ,,flick]4--,! flick]+ ( electric lights on l9es t supply wireless transmitt+ sets due to v>iations ( ! voltage on op5+ & clos+ ! key4 ,,load+ ,,coil4--,see ,coil1 ,load+4 ,,long ,,waves4--,see ,waves4 ,,loop ,,a]ial4--,see ,a]ial1 ,loop4 ,,loose ,,c\pl$ ,,circuits4--,see ,circuits1 ,loose ,c\pl$4 ,,l\d ,,speak]4--,a telephone receiv] connect$ to a horn1 or a specially made "o1 t reproduces ! incom+ signals1 words or music l\d en\gh to be he>d by a room or an auditorium full ( p1 or by l>ge cr[ds out-doors4 ,,magnetic ,,poles4--,see ,poles1 ,magnetic4 ,,megohm4--,"o million ohms4 ,,met]1 ,,audibility4--,an in/rum5t = measur+ ! l\dness ( a signal by comp>ison ) ano!r signal4 ,x consi/s ( a pair ( headphones & a v>iable resi/ance :i* h be5 calibrat$4 ,,mho4--,! unit ( conductance4 ,z conductance is ! reciprocal ( resi/ance x is measur$ by ! reciprocal ohm or mho4 ,,mica4--,a transp>5t m9]al hav+ a high insulat+ value & :i* c be split into v ?9 %eets4 ,x is l>gely us$ 9 mak+ cond5s]s bo? = transmitt+ & receiv+ sets4 ,,micr(>ad4--,! million? "p ( a f>ad4 ,,microh5ry4--,! million? "p ( a f>ad4 ,,micromicr(>ad4--,! million? "p ( a micr(>ad4 ,,microhm4--,! million? "p ( an ohm4 ,,microphone ,,trans=m]4--,see ,trans=m]1 ,microphone4 ,,microphone ,,transmitt]4--,see ,transmitt]1 ,microphone4 ,,milli-,,ammet]4--,an ammet] t measures a curr5t by ! "o-?\s&? ( an amp]e4 ,,modulation4--7#a7 ,inflection or v>y+ ! voice4 7#b7 ,v>y+ ! amplitude ( oscillations by means ( ! voice4 ,,modulation1 ,,buzz]4--,! modulation ( radio frequ5cy oscillations by a buzz] :i* breaks up ! su/a9$ oscillations ( a transmitt] into audio frequ5cy impulses4 ,,millih5ry4--,! ?\s&? "p ( a h5ry4 ,,modulation1 ,,*opp]4--,! modulation ( radio frequ5cy oscillations by a *opp] :i* breaks up ! su/a9$ oscillations ( a transmitt] into audio frequ5cy impulses4 ,,modulation1 ,,grid4--,! s*eme ( modulat+ an oscillator tube by connect+ ! second>y ( a trans=m]1 ! prim>y ( :i* is connect$ ) a batt]y & a microphone transmitt]1 9 ! grid lead4 ,,modulation1 ,,ov]4--,see ,blub ,blub4 ,,modulation1 ,,plate4--,modulat+ ! oscillations set up by a vacuum tube by v>y+ ! curr5t impress$ on ! plate4 ,,modulator ,,tube4--,a vacuum tube us$ z a modulator4 ,,motion1 ,,wave4--7#a7 ,! to & fro motion ( wat] at sea4 7#b7 ,waves transmitt$ by1 9 & ?r\gh ! air1 or s\nd waves4 7#c7 ,waves transmitt$ by1 9 & ?r\gh ! e!r1 or electromagnetic waves1 or electric waves = %ort4 ,,motor-,,g5]ator4--,a motor & a dynamo built to run at ! same spe$ & m\nt$ on a common base1 ! %afts be+ c\pl$ toge!r4 ,9 wireless x is us$ = *ang+ comm]cial direct curr5t into direct curr5t ( high] voltages = en]giz+ ! plate ( a vacuum tube oscillator4 ,,multi-,,/age ,,amplifi]s4--,see ,amplifi]s1 ,multi-,/age4 ,,mutual ,,induction4--,see ,induction1 ,mutual4 ,,mu%4--,irregul> int]m$iate frequ5cies set up by arc transmitt]s :i* int]f]e ) ! fundam5tal wave l5g?s4 ,,mu%y ,,note4--,a note t is n cle> cut1 & h5ce h>d to read1 :i* is receiv$ by ! het]odyne me?od :5 damp$ waves or modulat$ cont9u\s waves are be+ receiv$4 ,,national ,,electric ,,code4--,see ,code1 ,national ,electric4 ,,national ,,electric ,,safety ,,code4--,see ,code1 ,national ,electric ,safety4 ,,negative ,,electricity4--,see ,electricity1 ,negative4 ,,non-,,syn*ron\s ,,gap4--,see ,gap1 ,non-,syn*ron\s4 ,,ohm4--,! resi/ance ( a ?read ( m]cury at ! temp]ature ( melt+ ice1 #ad4deba grams 9 mass1 ( uni=m cross-section & a l5g? ( #ajf4cjj c5timet]s4 ,,ohm',s ,,law4--,! important fix$ relation betwe5 ! electric curr5t1 its electromotive =ce & ! resi/ance ( ! conductor 9 :i* x fl[s4 ,,op5 ,,circuit4--,see ,circuit1 ,op54 ,,op5 ,,core ,,trans=m]4--,see ,trans=m]1 ,op5 ,core4 ,,oscillation ,,trans=m]4--,see ,trans=m]1 ,oscillation4 ,,oscillations1 ,,electric4--,a curr5t ( high frequ5cy t surges ?r\gh an op5 or a clos$ circuit4 7#a7 ,electric oscillations may be set up by a sp>k gap1 electric arc or a vacuum tube1 :5 !y h n only a high frequ5cy b a high pot5tial1 or voltage4 7#b7 ,:5 electric waves imp+e on an a]ial wire !y are trans=m$ into electric oscillations ( a frequ5cy equal to ^? :i* emitt$ ! waves1 b s9ce a v small am\nt ( en]gy is receiv$ _! pot5tial or voltage is likewise v small4 ,su/a9$4--,oscillations 9 :i* ! damp+ factor is small4 ,damp$4--,oscillations 9 :i* ! damp+ factor is l>ge4 ,free4--,:5 a cond5s] dis*>ges ?r\gh an oscillation circuit1 :]e !re is no outside electromotive =ce act+ on x1 ! oscillations are said to be free4 ,=c$4--,oscillations t are made to surge 9 a circuit ^: natural p]iod is diff]5t f t ( ! oscillations set up 9 x4 ,,oscillation ,,trans=m]4--,see ,trans=m]4 ,,oscillation ,,valve4--,see ,vacuum ,tube4 ,,oscillator ,,tube4--,a vacuum tube :i* is us$ to produce electric oscillations4 ,,ov] ,,modulation4--,see ,blub ,blub4 ,,pancake ,,oscillation ,,trans=m]4--,disk-%ap$ coils t are us$ = receiv+ tun+ inductances4 ,,p]meability1 ,,magnetic4--,! degree to :i* a sub/ance c be magnetiz$4 ,iron has a great] magnetic p]meability ?an air4 ,,phase4--,a *>act]i/ic aspect or appe>ance t takes place at ! same po9t or "p ( a cycle4 ,,pick-,,up ,,circuits4--,see ,circuits1 ,/&-by4 ,,plate ,,circuit ,,reactor4--,see ,reactor1 ,plate ,circuit4 ,,plate ,,curr5t4--,see ,curr5t1 ,plate4 ,,plate ,,modulation4--,see ,modulation1 ,plate4 ,,plate ,,voltage4--,see ,foliage1 ,plate4 ,,poles1 ,,batt]y4--,! positive & negative t]m9als ( ! elem5ts ( a batt]y4 ,on a /orage batt]y ^! poles are m>k$ & - respectively4 ,,poles1 ,,magnetic4--,! ends ( a magnet4 ,,positive ,,electricity4--,see ,electricity1 ,positive4 ,,pot5tial ,,diff]5ce4--,! electric pressure betwe5 two *>g$ conductors or surfaces4 ,,pot5tiomet]4--,a v>iable resi/ance us$ = subdivid+ ! voltage ( a curr5t4 ,a voltage divid]4 ,,p[] ,,trans=m]4--,see ,trans=m]1 ,p[]4 ,,p[] ,,tube4--,see ,g5]ator ,tube4 ,,prim>y ,,batt]y4--,see ,batt]y1 ,prim>y4 ,,prev5tion1 ,,kick-,,back4--,a *oke coil plac$ 9 ! p[] circuit to prev5t ! high frequ5cy curr5ts f gett+ into ! trans=m] & break+ d[n ! insulation4 ,q ,s ,t4--,an abbreviation us$ 9 wireless communication = 7#a7 ! "q ,h y receiv$ ! g5]al call8 & 7#b7 ! notice1 ,g5]al call to all /ations4 ,,qu5*$ ,,gap4--,see ,gap1 ,qu5*$4 ,,radiation4--,! emission1 or ?r[+ (f1 ( electric waves by an a]ial wire sy/em4 ,,radio ,,ammet]4--,see ,ammet]1 ,hot ,wire4 ,,radio ,,frequ5cy4--,see ,frequ5cy1 ,radio4 ,,radio ,,frequ5cy ,,amplification4--,see ,amplification1 ,radio ,frequ5cy4 ,,radio ,,frequ5cy ,,curr5t4--,see ,curr5t1 ,radio ,frequ5cy4 ,,radio ,,inspector4--,see ,inspector1 ,radio4 ,,radiotron4--,! trade "n ( vacuum tube detectors1 amplifi]s1 oscillators & modulators made by ! ,radio ,corporation ( ,am]ica4 ,,radio ,,waves4--,see ,waves1 ,radio4 ,,reactance4--,:5 a circuit has inductance & ! curr5t *anges 9 value1 x is oppos$ by ! voltage induc$ by ! v>iation ( ! curr5t4 ,,reactance1 ,,capacity4--,! capacity reactance is ! opposition (f]$ to a curr5t by a capacity4 ,x is measur$ z a resi/ance1 t is1 9 ohms4 ,,receiv+ ,,tun+ ,,coils4--,see ,coils1 ,inductance4 ,,receiv]1 ,,l\d ,,speak+4--,see ,l\d ,speak]s4 ,,receiv]1 ,,wat* ,,case4--,a compact telephone receiv] us$ = wireless reception4 ,,reactance1 ,,inductive4--,! inductive reactance is ! opposition (f]$ to ! curr5t by an inductance coil4 ,x is measur$ z a resi/ance1 t is1 9 ohms4 ,,reactor1 ,,filt]4--,a reactance coil = smoo?+ out ! pulsat+ direct curr5ts z !y come f ! rectifi]4 ,,reactor1 ,,plate ,,circuit4--,a reactance coil us$ 9 ! plate circuit ( a wireless telephone to keep ! direct curr5t supply at a con/ant voltage4 ,,receiv]4--7#a7 ,a telephone receiv]4 7#b7 ,an app>atus = receiv+ signals1 spee* or music4 7#c7 ,bett] call$ a receptor to di/+ui% x f a telephone receiv]4 ,,rectifi]4--7#a7 ,an app>atus = *ang+ alt]nat+ curr5t into pulsat+ direct curr5t4 7#b7 ,specifically 9 wireless 7a7 a cry/al or vacuum tube detector1 & 7b7 a two-electrode vacuum tube us$ = *ang+ comm]cial alt]nat+ curr5t into direct curr5t = wireless telephony4 ,,reg5]ative ,,amplification4--,see ,amplification1 ,reg5]ative4 ,,receptor4--,a receiv+ set4 ,,receptor1 ,,autodyne4--,a receptor t has a reg5]ative circuit & ! same tube is us$ z a detector & z a g5]ator ( local oscillations4 ,,receptor1 ,,beat4--,a het]odyne receptor4 ,,receptor1 ,,het]odyne4--,a receiv+ set t uses a sep>ate vacuum tube to set up ! second s]ies ( waves = beat reception4 ,,reg5]ative ,,action4--,see ,fe$-,back ,action4 ,,reg5]ative ,,amplification4--,see ,amplification1 ,reg5]ative4 ,,relay1 ,,electron4--,a vacuum tube :5 us$ z a detector or an amplifi]4 ,,repeat+ ,,coil4--,a trans=m] us$ 9 connect+ up a wireless receiv] ) a wire transmitt]4 ,,resi/ance4--,! opposition (f]$ by a wire or o!r conductor to ! passage ( a curr5t4 ,,resi/ance1 ,,a]ial4--,! resi/ance ( ! a]ial wire to oscillat+ curr5ts4 ,?is is great] ?an its ord9>y ohmic resi/ance due to ! sk9 effect4 ,see ,resi/ance1 ,high ,frequ5cy4 ,,resi/ance ,,box4--,see ,resi/or4 ,,resi/ance ,,c\pl+4--,see ,c\pl+1 ,resi/ance4 ,,resi/ance1 ,,high ,,frequ5cy4--,:5 a high frequ5cy curr5t oscillates on a wire two ?+s take place t are diff]5t ?an :5 a direct or alt]nat+ curr5t fl[s ?r\gh x1 & ^! are 7#a7 ! curr5t inside ( ! wire lags beh9d t ( ! curr5t on ! surface1 & 7#b7 ! amplitude ( ! curr5t is l>ge/ on ! surface & gr[s small] z ! c5t] ( ! wire is rea*$4 ,?is unev5 di/ribution ( ! curr5t is kn[n z ! sk9 effect & x am\nts to ! same ?+ z r$uc+ ! size ( ! wire1 h5ce ! resi/ance is increas$4 ,,resi/ivity4--,! resi/ance ( a giv5 l5g? ( wire ( uni=m cross section4 ,! reciprocal ( conductivity4 ,,resi/or4--,a fix$ or v>iable resi/ance unit or a gr\p ( su* units4 ,v>iable resi/ors are also call$ resi/ance boxes & m (t5 rheo/ats4 ,,resonance4--7#a7 ,simple resonance ( s\nd is its increase set up by "o body by ! sympa!tic vibration ( a second body4 7#b7 ,by ext5sion ! increase 9 ! amplitude ( electric oscillations :5 ! circuit 9 :i* !y surge has a natural p]iod t is ! same1 or ne>ly ! same1 z ! p]iod ( ! fir/ oscillation circuit4 ,,rheo/at4--,a v>iable resi/ance unit4 ,see ,resi/or4 ,,rheo/at1 ,,c>bon4--,a c>bon rod1 or c>bon plates or blocks1 :5 us$ z v>iable resi/ances4 ,,rheo/at1 ,,filam5t4--,a v>iable resi/ance us$ = keep+ ! curr5t ( ! /orage batt]y :i* heats ! filam5t ( a vacuum tube at a con/ant voltage4 ,,rotat+ ,,coil4--,see ,coil4 ,,rot>y ,,gap4--,see ,gap4 ,,rotor4--,! rotat+ coil ( a v>iomet] or a v>ioc\pl]4 ,,ruhmkorff ,,coil4--,see ,coil1 ,induction4 ,,saturation4--,! maximum plate curr5t t a vacuum tube w take4 ,,s5sitive ,,spots4--,spots on detector cry/als t are s5sitive to ! action ( electric oscillations4 ,,%ort ,,waves4--,see ,waves4 ,,side ,,waves4--,see ,wave ,l5g? ,b&4 ,,signals1 ,,conv5tional4--7#a7 ,! ,int]national ,morse alphabet & num]al code1 punctuation m>ks1 & a few important abbreviations us$ 9 wireless telegraphy4 7#b7 ,dot & da% signals = di/ress call1 invitation to transmit1 etc4 ,n[ us$ = all g5]al public s]vice wireless communication4 ,,sk9 ,,effect4--,see ,resi/ance1 ,high ,frequ5cy4 ,,s(t ,,tube4--,a vacuum tube 9 :i* ! vacuum is l[1 t is1 x is n highly exhau/$4 ,,space ,,*>ge ,,effect4--,! electric field int5sity due to ! pressure ( ! negative electrons 9 ! space betwe5 ! filam5t & plate :i* at la/ equals & neutralizes t due to ! positive pot5tial ( ! plate s t !re is no =ce act+ on ! electrons ne> ! filam5t4 ,,sp>k4--,see ,dis*>ge4 ,,sp>k ,,coil4--,see ,coil1 ,induction4 ,,sp>k ,,dis*>ge4--,see ,sp>k1 ,electric4 ,,sp>k ,,frequ5cy4--,see ,frequ5cy1 ,sp>k4 ,,sp>k ,,gap4--7#a7 ,a sp>k gap1 )\t ! hyph51 means ! app>atus 9 :i* sp>ks take place2 x is also call$ a sp>k dis*>g]4 7#b7 ,sp>k-gap1 ) ! hyph51 means ! air-gap betwe5 ! oppos$ faces ( ! electrodes 9 :i* sp>ks are produc$4 ,pla94--,a sp>k gap ) fix$ electrodes4 ,rot>y4--,a sp>k gap ) a pair ( fix$ electrodes & a numb] ( electrodes m\nt$ on a rotat+ elem5t4 ,qu5*$4--,a sp>k gap =m$ ( a numb] ( metal plates plac$ closely toge!r & insulat$ f ea* o!r4 ,,spid] ,,web ,,inductance ,,coil4--,see ,coil1 ,spid] ,web ,inductance4 ,,spread]4--,a /ick ( wood1 or sp>1 t holds ! wires ( ! a]ial ap>t4 ,,/agg] ,,w\nd ,,coils4--,see ,coils1 ,inductance4 ,,/&-,,by ,,circuits4--,see ,circuits1 ,/&-,by4 ,,/atic4--,also call$ atmosph]ics1 gr9d]s1 /rays1 ,x's1 &1 :5 bad en\gh1 by o!r names4 ,x is an electrical di/urbance 9 ! atmosph]e :i* makes noises 9 ! telephone receiv]4 ,,/ator4--,! fix$ or /ation>y coil ( a v>iomet] or a v>ioc\pl]4 ,,/orage ,,batt]y4--,see ,batt]y1 ,/orage4 ,,/ray ,,elim9ation4--,a me?od = increas+ ! /r5g? ( ! signals z aga9/ ! /r5g? ( ! /rays4 ,see ,/atic4 ,,/rays4--,see ,/atic4 ,,/r&$ ,,wire4--,see ,wire1 ,/r&$4 ,,sup]-,,het]odyne ,,receptor4--,see ,het]odyne1 ,sup]4 ,,sw++4--,see ,fad+4 ,,swit*1 ,,a]ial4--,a swit* us$ to *ange ov] f ! s5d+ to ! receiv+ set1 & ! o!r way ab\t1 & connect !m ) ! a]ial4 ,,swit*1 ,,lightn+4--,! swit* t connects ! a]ial ) ! outside gr\nd :5 ! app>atus is n 9 use4 ,,symbols1 ,,app>atus4--,also call$ conv5tional symbols4 ,^! are diagrammatic l9es repres5t+ v>i\s p>ts ( app>atus s t :5 a wir+ diagram ( a transmitt] or a receptor is to be made x is only necess>y to connect !m toge!r4 ,!y are easy to make & easy to read4 ,see ,page #cjg ,app5dix3 ,symbols ,us$ = ,app>atus4 ,,syn*ron\s ,,gap4--,see ,gap1 ,syn*ron\s4 ,,telephony1 ,,l9e ,,radio4--,see ,wir$ ,wireless4 ,,!rmal ,,ammet]4--,see ,ammet]1 ,hot ,wire4 ,,?ree ,,electrode ,,vacuum ,,tube4--,see ,vacuum ,tube1 ,?ree ,electrode4 ,,tikk]4--,a slipp+ contact device t breaks up ! su/a9$ oscillations at ! receiv+ end into gr\ps s t ! signals c be he>d 9 ! head phones4 ,! device usually consi/s ( a f9e /eel or gold wire slipp+ 9 ! smoo? groove ( a rotat+ brass :eel4 ,,trans=m]4--,a prim>y & a second>y coil = /epp+ up or d[n a prim>y alt]nat+ or oscillat+ curr5t4 ,a4 ,c4--,see ,p[] ,trans=m]4 ,air ,cool$4--,a trans=m] 9 :i* ! coils are expos$ to ! air4 ,air ,core4--,) high frequ5cy curr5ts x is ! g5]al practice n to use iron cores z ^! t5d to *oke (f ! oscillations4 ,h5ce ! core consi/s ( ! air inside ( ! coils4 ,auto4--,a s+le coil ( wire 9 :i* "o "p =ms ! prim>y & ! o!r "p ! second>y by br++ out an int]m$iate tap4 ,audio ,amplify+4--,?is is a trans=m] ) an iron core & is us$ = frequ5cies up to say #c1jjj4 ,clos$ ,core4--,a trans=m] 9 :i* ! pa? ( ! magnetic flux is entirely ?r\gh iron4 ,p[] trans=m]s h clos$ cores4 ,microphone4--,a small trans=m] = modulat+ ! oscillations set up by an arc or a vacuum tube oscillator4 ,oil ,cool$4--,a trans=m] 9 :i* ! coils are imm]s$ 9 oil4 ,op5 ,core4--,a trans=m] 9 :i* ! pa? ( ! magnetic flux is p>tly ?r\gh iron & p>tly ?r\gh air4 ,induction coils h op5 cores4 ,oscillation4--,a coil or coils = trans=m+ or /epp+ d[n or up oscillat+ curr5ts4 ,oscillation trans=m]s usually h no iron cores :5 !y are also call$ air core trans=m]s4 ,p[]4--,a trans=m] = /epp+ d[n a comm]cial alt]nat+ curr5t = light+ & heat+ ! filam5t & = /epp+ up ! comm]cial a4c41 = *>g+ ! plate ( a vacuum tube oscillator4 ,radio ,amplify+4--,?is is a trans=m] ) an air core4 ,x does n 9 itself amplify b is s call$ because x is us$ 9 connection ) an amplify+ tube4 ,,transmitt]1 ,,microphone4--,a telephone transmitt] ( ! k9d t is us$ 9 ! ,bell telephone sy/em4 ,,transmitt+ ,,tun+ ,,coils4--,see ,coils1 ,inductance4 ,,tun+4--,:5 ! op5 & clos$ oscillation circuits ( a transmitt] or a receptor are adju/$ s t bo? ( ! =m] w p]mit electric oscillations to surge ?r\gh !m ) ! same frequ5cy1 !y are said to be tun$4 ,likewise1 :5 ! s5d+ & receiv+ /ations are adju/$ to ! same wave l5g? !y are said to be tun$4 ,co>se ,tun+4--,! fir/ adju/m5t 9 ! tun+ oscillation circuits ( a receptor is made ) ! inductance coil & ?is tunes !m co>se1 or r\ghly4 ,f9e ,tun+4--,aft] ! oscillation circuits h be5 r\ghly tun$ ) ! inductance coil ! exact adju/m5t is obta9$ ) ! v>iable cond5s] & ?is is f9e tun+4 ,%>p4--,:5 a s5d+ set w transmit or a receiv+ set w receive a wave ( giv5 l5g? only x is said to be %>ply tun$4 ,! small] ! decrem5t ! %>p] ! tun+4 ,,tun+ ,,coils4--,see ,coils1 ,inductance4 ,,two ,,electrode ,,vacuum ,,tube4--,see ,vacuum ,tube1 ,two ,electrode4 ,,vacuum ,,tube4--,a tube ) two or ?ree electrodes f :i* ! air has be5 exhau/$1 or :i* is fill$ ) an in]t gas1 & us$ z a detector1 an amplifi]1 an oscillator or a modulator 9 wireless telegraphy & telephony4 ,amplifi]4--,see ,amplifi]1 ,vacuum ,tube4 ,amplify+ ,modulator4--,a vacuum tube us$ = modulat+ & amplify+ ! oscillations set up by ! s5d+ set4 ,gas ,cont5t4--,a tube made l a vacuum tube & us$ z a detector b :i* conta9s an in]t gas in/ead ( be+ exhau/$4 ,h>d4--,see ,h>d ,tube4 ,rectifi]4--7#a7 ,a vacuum tube detector4 7#b7 a two-electrode vacuum tube us$ = *ang+ comm]cial alt]nat+ curr5t into direct curr5t = wireless telephony4 ,s(t4--,see ,s(t ,tube4 ,?ree ,electrode4--,a vacuum tube ) ?ree electrodes1 namely a filam5t1 a grid & a plate4 ,two ,electrode4--,a vacuum tube ) two electrodes1 namely ! filam5t & ! plate4 ,,valve4--,see ,vacuum ,tube4 ,,valve1 ,,flem+4--,see ,flem+ ,valve4 ,,v>iable ,,cond5s]4--,see ,cond5s]1 ,v>iable4 ,,v>iable ,,inductance4--,see ,inductance1 ,v>iable4 ,,v>iable ,,resi/ance4--,see ,resi/ance1 ,v>iable4 ,,v>ioc\pl]4--,a tun+ device = v>y+ ! inductance ( ! receiv+ oscillation circuits4 ,x consi/s ( a fix$ & a rotatable coil ^: w9d+s are n connect$ ) ea* o!r4 ,,v>iomet]4--,a tun+ device = v>y+ ! inductance ( ! receiv+ oscillation curr5ts4 ,x consi/s ( a fix$ & a rotatable coil ) ! coils connect$ 9 s]ies4 ,,v]ni] ,,cond5s]4--,see ,cond5s]1 ,v]ni]4 ,,volt4--,! electromotive =ce :i* produces a curr5t ( #a amp]e :5 /eadily appli$ to a conductor ! resi/ance ( :i* is "o ohm4 ,,voltage ,,divid]4--,see ,pot5tiomet]4 ,,voltage1 ,,plate4--,! voltage ( ! curr5t t is us$ to en]gize ! plate ( a vacuum tube4 ,,voltmet]4--,an in/rum5t = measur+ ! voltage ( an electric curr5t4 ,,wat* ,,case ,,receiv]4--,see ,receiv]1 ,wat* ,case4 ,,wat]-,,pipe ,,gr\nd4--,see ,gr\nd1 ,wat]-,pipe4 ,,watt4--,! p[] sp5t by a curr5t ( #a amp]e 9 a resi/ance ( #a ohm4 ,,wave1 ,,broad4--,a wave hav+ a high decrem5t1 :5 ! /r5g? ( ! signals is ne>ly ! same ov] a wide range ( wave l5g?s4 ,,wave ,,l5g?4--,e wave ( :atev] k9d has a l5g?4 ,! wave l5g? is usually tak5 to mean ! di/ance betwe5 ! cre/s ( two successive waves4 ,,wave ,,l5g? ,,b&4--,9 wireless reception :5 cont9u\s waves are be+ s5t out & ^! are modulat$ by a microphone transmitt] ! diff]5t audio frequ5cies set up correspond+ radio frequ5cies & ! en]gy ( ^! are emitt$ by ! a]ial2 ?is results 9 waves ( diff]5t l5g?s1 or a b& ( waves z x is call$4 ,,wave ,,met]4--,an app>atus = measur+ ! l5g?s ( electric waves set up 9 ! oscillation circuits ( s5d+ & receiv+ sets4 ,,wave ,,motion4--,di/urbances set up 9 ! surr\nd+ m$ium z wat] waves 9 & on ! wat]1 s\nd waves 9 ! air & electric waves 9 ! e!r4 ,,waves4--,see ,wave ,motion4 ,,waves1 ,,electric4--,electromagnetic waves set up 9 & transmitt$ by & ?r\gh ! e!r4 ,cont9u\s4 ,abbreviat$ ,c4,w4--,waves t are emitt$ )\t a break f ! a]ial4 ,also call$ undamp$ waves4 ,discont9u\s4--,waves t are emitt$ p]iodically f ! a]ial4 ,also call$ damp$ waves4 ,damp$4--,see ,discont9u\s ,waves4 ,int]m$iate4--,waves f #fjj to #b1jjj met]s 9 l5g?4 ,long4--,waves ov] #b1jjj met]s 9 l5g?4 ,radio4--,electric waves us$ 9 wireless telegraphy & telephony4 ,%ort4--,waves up to #fjj met]s 9 l5g?4 ,wireless4--,electric waves us$ 9 wireless telegraphy & telephony4 ,undamp$4--,see ,cont9u\s ,waves4 ,,wireless ,,telegraph ,,code4--,see ,code1 ,int]national4 ,,wire1 ,,enamell$4--,wire t is giv5 a ?9 coat ( enamel :i* insulates x4 ,,wire1 ,,phosphor ,,bronze4--,a v /rong wire made ( an alloy ( copp] & conta9+ a trace ( phosphorus4 ,,wir$ ,,wireless4--,cont9u\s waves ( high frequ5cy t are s5t ov] telephone wires in/ead ( ?r\gh space4 ,also call$ l9e radio communication2 c>ri] frequ5cy telephony1 c>ri] curr5t telephony2 guid$ wave telephony & wir$ wireless4 ,x',s4--,see ,/atic4 ,,z9cite4--,see ,detector4 ,,wireless ,,don',,ts ,,a]ial ,,wire ,,don',,ts ,don't use iron wire = y\r a]ial4 ,don't fail to insulate x well at bo? ends4 ,don't h x long] ?an #ge feet = s5d+ out a #bjj-met] wave4 ,don't fail to use a lightn+ arre/]1 or bett]1 a lightn+ swit*1 = y\r receiv+ set4 ,don't fail to use a lightn+ swit* ) y\r transmitt+ set4 ,don't =get y mu/ h an outside gr\nd4 ,don't fail to h ! resi/ance ( y\r a]ial z small z possible4 ,use /r&$ wire4 ,don't fail to sold] ! lead+-9 wire to ! a]ial4 ,don't fail to prop]ly insulate ! lead+-9 wire :]e x goes ?r\gh ! w9d[ or wall4 ,don't let y\r a]ial or lead+-9 wire t\* trees or o!r objects4 ,don't let y\r a]ial come too close to ov]head wires ( any k9d4 ,don't run y\r a]ial directly "u1 or ov]1 or p>allel ) electric light or o!r wires4 ,don't fail to make a good gr\nd connection ) ! wat] pipe inside4 ,,transmitt+ ,,don',,ts ,don't attempt to s5d until y get y\r lic5se4 ,don't fail to live up to e rule & regulation4 ,don't use an input ( m ?an #a_/b a kil[att if y live )9 #e nautical miles ( a naval /ation4 ,don't s5d on m ?an a #bjj-met] wave if y h a re/rict$ or g5]al amateur lic5se4 ,don't use sp>k gap electrodes t are too small or !y w get hot4 ,don't use too long or too %ort a sp>k gap4 ,! "r l5g? c be f\nd by try+ x out4 ,don't fail to use a safety sp>k gap betwe5 ! grid & ! filam5t t]m9als :]e ! plate pot5tial is above #b1jjj volts4 ,don't buy a motor-g5]ator set if y h comm]cial alt]nat+ curr5t 9 y\r home4 ,don't ov]load an oscillation vacuum tube z x w greatly %ort5 its life4 ,use two 9 p>allel4 ,don't op]ate a transmitt+ set )\t a hot-wire ammet] 9 ! a]ial4 ,don't use solid wire = connect+ up ! p>ts ( transmitt]s4 ,use /r&$ or braid$ wire4 ,don't fail to sold] ea* connection4 ,don't use sold]+ fluid1 use ros94 ,don't ?9k t all ( ! en]gy ( an oscillation tube _c be us$ = wave l5g?s ( #bjj met]s & "u4 ,x c be if ! transmitt+ set & a]ial are prop]ly design$4 ,don't run ! wires ( oscillation circuits too close toge!r4 ,don't cross ! wires ( oscillation circuits except at "r angles4 ,don't set ! trans=m] ( a transmitt+ set ne>] ?an #c feet to ! cond5s] & tun+ coil4 ,don't use a rot>y gap 9 :i* ! :eel runs out ( true4 ,,receiv+ ,,don',,ts ,don't expect to get z good results ) a cry/al detector z ) a vacuum tube detector4 ,don't be disc\rag$ if y fail to hit ! s5sitive spot ( a cry/al detector ! fir/ "t--or sev]al times !reaft]4 ,don't use a wire l>g] ?an ,no4 #hj = ! wire electrode ( a cry/al detector4 ,don't try to use a l\d speak] ) a cry/al detector receiv+ set4 ,don't expect a loop a]ial to give wor?:ile results ) a cry/al detector4 ,don't h&le cry/als ) y\r f+]s z ?is de/roys _! s5sitivity4 ,use tweez]s or a clo?4 ,don't imb$ ! cry/al 9 sold] z ! heat de/roys its s5sitivity4 ,use ,wood's metal1 or "s o!r alloy :i* melts at or ne> ! temp]ature ( boil+ wat]4 ,don't =get t /rong /atic & /rong signals sometimes de/roy ! s5sitivity ( cry/als4 ,don't heat ! filam5t ( a vacuum tube to great] brilliancy ?an is necess>y to secure ! s5sitiv5ess requir$4 ,don't use a plate voltage t is less or m ?an x is rat$ =4 ,don't connect ! filam5t to a light+ circuit4 ,don't use dry cells = heat+ ! filam5t except 9 a p9*4 ,don't use a con/ant curr5t to heat ! filam5t1 use a con/ant voltage4 ,don't use a vacuum tube 9 a horizontal position unless x is made to be s us$4 ,don't fail to prop]ly insulate ! grid & plate leads4 ,don't use m ?an #a_/c ( ! rat$ voltage on ! filam5t & on ! plate :5 try+ x out = ! fir/ "t4 ,don't fail to use alt]nat+ curr5t = heat+ ! filam5t :]e ?is is possible4 ,don't fail to use a voltmet] to f9d ! prop] temp]ature ( ! filam5t4 ,don't expect to get results ) a l\d speak] :5 us+ a s+le vacuum tube4 ,don't fail to protect y\r vacuum tubes f me*anical %ocks & vibration4 ,don't fail to cut (f ! ,a batt]y entirely f ! filam5t :5 y are ?r\gh receiv+4 ,don't swit* on ! ,a batt]y curr5t all at once ?r\gh ! filam5t :5 y />t to receive4 ,don't expect to get ! be/ results ) a gas-cont5t detector tube )\t us+ a pot5tiomet]4 ,don't connect a pot5tiomet] across ! ,b batt]y or x w spe$ily run d[n4 ,don't expect to get z good results ) a s+le coil tun] z y w\ld ) a loose c\pl]4 ,don't expect to get z good results ) a two-coil tun] z ) "o hav+ a ?ird1 or tickl]1 coil4 ,don't ?9k y h to use a reg5]ative circuit1 t is1 "o ) a tickl] coil1 to receive ) a vacuum tube detector4 ,don't ?9k y are ! only amateur :o is tr\bl$ ) /atic4 ,don't expect to elim9ate int]f]5ce if ! amateurs ar\nd y are s5d+ ) sp>k sets4 ,don't lay out or assemble y\r set on a panel fir/4 ,connect x up on a bo>d & f9d out if ev]y?+ is "r4 ,don't try to connect up y\r set )\t a wir+ diagram 9 front ( y4 ,don't fail to %ield radio frequ5cy amplifi]s4 ,don't set ! axes ( ! cores ( radio frequ5cy trans=m]s 9 a l9e4 ,set !m at "r angles to ea* o!r4 ,don't use wire small] ?an ,no4 #ad = connect+ up ! v>i\s p>ts4 ,don't fail to adju/ ! ,b batt]y aft] putt+ 9 a fre% vacuum tube1 z its s5sitivity dep5ds l>gely on ! voltage4 ,don't fail to prop]ly space ! p>ts :]e y use v>iomet]s4 ,don't fail to put a copp] %ield betwe5 ! v>iomet] & ! v>ioc\pl]4 ,don't fail to keep ! leads to ! vacuum tube z %ort z possible4 ,don't ?r[ y\r receiv+ set out ( ! w9d[ if x h[ls4 ,try plac+ ! audio-frequ5cy trans=m]s f>!r ap>t & ! cores ( !m at "r angles to ea* o!r4 ,don't use cond5s]s ) pap] dielectrics = an amplifi] receiv+ set or x w be noisy4 ,don't expect z good results ) a loop a]ial1 or :5 us+ ! b$ spr+s1 z an out-door a]ial w give y4 ,don't use an amplifi] hav+ a plate pot5tial ( less ?an #ajj volts = ! la/ /ep :]e a l\d speak] is to be us$4 ,don't try to assemble a set if y don't "k ! diff]5ce betwe5 a b9d+ po/ & a blue pr9t4 ,buy a set ready to use4 ,don't expect to get ,arl+ton "t signals & ! big cableless /ations if y\r receiv] is made = %ort wave l5g?s4 ,don't take y\r headphones ap>t4 ,y are j z apt to spoil !m z y w\ld a wat*4 ,don't expect to get results ) a ,bell telephone receiv]4 ,don't =get t !re are o!r op]ators us+ ! e!r besides y\rself4 ,don't let y\r ,b batt]y get damp & don't let x freeze4 ,don't try to re*>ge y\r ,b batt]y unless x is con/ruct$ = ! purpose4 ,,/orage ,,batt]y ,,don',,ts ,don't connect a s\rce ( alt]nat+ curr5t direct to y\r /orage batt]y4 ,y h to use a rectifi]4 ,don't connect ! positive lead ( ! *>g+ circuit ) ! negative t]m9al ( y\r /orage batt]y4 ,don't let ! electrolyte get l[] ?an ! tops ( ! plates ( y\r /orage batt]y4 ,don't fail to look aft] ! condition ( y\r /orage batt]y once 9 a :ile4 ,don't buy a /orage batt]y t gives less ?an #f volts = heat+ ! filam5t4 ,don't fail to keep ! specific gravity ( ! electrolyte ( y\r /orage batt]y betwe5 #a4bbe & #a4cjj ,baume4 ,?is y c d ) a hydromet]4 ,don't fail to re*>ge y\r /orage batt]y :5 ! hydromet] %[s t ! specific gravity ( ! electrolyte is close to #a4bbe4 ,don't keep *>g+ ! batt]y aft] ! hydromet] %[s t ! specific gravity is #a4bhe4 ,don't let ! /orage batt]y freeze4 ,don't let x /& = long] ?an a mon? )\t us+ unless y *>ge x4 ,don't monkey ) ! /orage batt]y except to add a little sulphuric acid to ! electrolyte f "t to "t4 ,if any?+ goes wrong ) x bett] take x to a s]vice /ation & let ! exp]t d x4 ,,extra ,,don',,ts ,don't ?9k y h an up-to-date transmitt+ /ation unless y are us+ ,c4,w4 ,don't use a wire f y\r lightn+ swit* d[n to ! outside gr\nd t is small] ?an ,no4 #d4 ,don't try to op]ate y\r sp>k coil ) #aaj-volt direct light+ curr5t )\t connect+ 9 a rheo/at4 ,don't try to op]ate y\r sp>k coil ) #aaj-volt alt]nat+ light+ curr5t )\t connect+ 9 an electrolytic int]rupt]4 ,don't try to op]ate an alt]nat+ curr5t p[] trans=m] ) #aaj-volt direct curr5t )\t connect+ 9 an electrolytic int]ruptor4 ,don't--no nev]--connect "o side ( ! sp>k gap to ! a]ial wire & ! o!r side ( ! sp>k gap to ! gr\nd4 ,! ,gov]nm5t won't h x--t's all4 ,don't try to tune y\r transmitt] to s5d out waves ( giv5 l5g? by guesswork4 ,use a wavemet]4 ,don't use h>d fib] = panels4 ,x is a v poor insulator :]e high frequ5cy curr5ts are us$4 ,don't ?9k y are ! only "o :o doesn't "k all ab\t wireless4 ,wireless is a v complex art & !re are _m ?+s t ^? exp]i5c$ h /ill to le>n4 ,,! ,,end4