,transcriber's ,note ,in this transcription1 bold text is denoted by equal signs4 ,small capitals in the original text have been transcribed as ,title ,case4 ,see end of this document for details of corrections and other changes4 ---------------------------- ,start of ,book ---------------------------- ,,telephone ,,troubles ,,their ,,location ,,and ,,remedy4 ,,by ,e4 ,m4 ,,wev4 ,,new ,,york3 ,,mcgraw ,,publishing ,,company4 #aijg4 ,copyrighted1 #aijg1 by the ,mc,graw ,publishing ,company1 ,new ,york4 ,,note4 ,in putting this little book before the telephone workers ,i do so with the idea of helping the beginner and furnishing a guide for the experienced man4 ,it is composed of information gained by #ae years' practical experience4 ,e4 ,m4 ,w ,april1 #aijg4 ,,contents4 ,,chapter4 ,,page4 ,i4 ,direct ,line #a ,,ii4 ,two ,party ,line #ad ,,iii4 ,four ,party ,set #ag ,,iv4 ,how to ,test ,for and ,clear ,troubles in ,private ,branch ,exchange ,switchboards #be ,inspection #dj ,,telephone ,,troubles4 -------------- ,,chapter ,i4 ,,direct ,,line4#a ,bell ,doesn't ,ring at all4 ,may be caused by any of following3 #ast4 ,condenser open4 #b;d4 ,ringer open4 #c;d4 ,hook contacts crossed4 #dth4 ,desk stand cords or induction coil crossed4 #eth4 ,extention bell open4 #fth4 ,ringer short-circuited4 #gth4 ,trouble at central office4 #ast4 ,when condenser is open you will get weak hook clicks and side tones and hearing very weak4 ,prove by short-circuiting the condenser at the lugs with a test cord1 which should make the ring of the bell and hearing ,o4,k4 7,while the condenser is short-circuited you will get only one hook click47 #b;d4 ,only one hook click1 the side tones normal1 and the failure of the ringer armature to move when you raise or lower the hook1 indicates that the ringer is open4 ,prove by replacing the receiver on the hook and then bridge across the condenser lugs with your head receiver2 if you do not get a good click every time you make contact1 the ringer is open4 ,or you can make the following test2 open the strap at the top of the bell1 then short-circuit the condenser lugs with a test cord2 then connect one side of your head receiver to one of the line binding posts1 and feel with the other side on the terminals of the ringer2 if you get battery on one terminal and not on the other the ringer is certainly open4 #c;d4 ,only one hook click1 side tones normal1 failure of the ringer armature to move when you raise and lower the hook1 and the receiver in circuit while the hook is down1 indicates that the hook contacts are crossed together4 ,when this is the case1 the bell will ring poorly or not at all1 and the ring can be heard in the receiver when the hook is down4 ,open the receiver circuit at one of the receiver binding posts1 this should allow the bell to ring all right4 #dth4 ,red and white strands of desk stand cord or primary and secondary of induction coil crossed together will generally cut down hearing2 it may or may not cause only one hook click1 and may or may not put battery through the receiver1 and may wholly or only partly prevent the bell from ringing4 ,disconnect the strap on top of the bell and test with your head receiver from the ,g post to the ,l#b post2 if you get battery there is a cross2 disconnect the red and white strands of the desk stand cord1 this will show whether the trouble is in the desk stand cord or in the bell4 ,if it is in the bell1 disconnect ,no4 #b and ,no4 #d terminals of the induction coil1 and test again1 to prove certainly that the trouble is in the coil itself and not in the wiring4 #eth4 ,if there is an auxiliary bell1 and it is open1 the set will test as though it had an open ringer4 ,test by short-circuiting the ,l#b and ,g posts1 which cuts out the auxiliary bell and makes it a straight set for the time being4 #fth4 ,if the ringer is short-circuited you will get battery through the receiver1 which can be detected by listening while you short-circuit the receiver binding posts with your screw driver blade4 ,to prove1 disconnect the bridge from the top of the bell1 and connect the two line wires to the ,l#b and ,g posts instead of the ,l#b and ,l#a posts2 short-circuit the condenser lugs with a test cord1 and then bridge your head receiver across the ringer terminals2 if the ringer is all right you will get a heavy click1 if it is completely short-circuited you will get no click at all1 if it is partially short-circuited you will get a partial click4 ,bell ,rings ,weakly4 ,may be caused by3 ,poor adjustment of armature or gongs4 ,pivot screws too loose or too tight4 ,clapper rubbing on guard4 ,wiring interfering with the clapper stem4 8,whiskers0 on the magnet heads4 ,magnet heads sticky or gummy4 ,desk stand cord1 induction coil1 or hook contacts crossed4 ,one or both coils of the ringer partially short-circuited4 ,polarizing magnet weak4 ,carbons in protector dirty and generator current jumping across them4 ,trouble at the central office4 ,bridge on the ,line1 ,steady ,light at ,central ,office4 ,prove whether the trouble is in the instrument or not by disconnecting both sides of the line at the top of the bell and going in with your head receiver4 ,if you get central the trouble is in the instrument and the same will be found either in the wiring1 desk stand cords1 or the hook4 ,if opening the strap 7see diagram ,no4 #a7 does clear the trouble1 the leak is across through the ringer1 and must be due to3 #a4 ,receiver contact of hook not breaking4 ,if this is the case1 opening the receiver circuit at one of the receiver binding posts will clear the trouble temporarily4 #b4 ,white and green strands of the desk stand cord crossed together4 ,if this is the trouble1 disconnecting the cords from the bell will clear it4 ,illustration3 ,fig4 #a4 #c4 ,the condenser must be short-circuited if the trouble is not in the hook or cords2 if the condenser is completely short-circuited1 there will be but one hook click1 but often there is enough resistance in a condenser short-circuit to give both hook clicks4 ,to make sure that the trouble is in the condenser itself1 and not in the wiring1 disconnect one terminal of the condenser and go in series with your head receiver4 ,instrument ,entirely ,dead1 ,nothing can be ,heard in the ,receiver4 ,see first that you have battery at the top of the bell4 ,the trouble may be due to3 #a4 ,receiver circuit open4 #b4 ,receiver short-circuited4 #a4 ,if there is an open in the receiver circuit1 it may be in either the receiver itself1 the receiver cord1 the white strand of the desk stand cord1 the receiver contact of the hook1 or the secondary2 bridge your head receiver successively around these parts1 when you bridge around the open you will get the side tones in the head receiver4 #b4 ,to prove whether a receiver is short-circuited or not1 connect your head receiver in series with it2 if the head receiver responds while another receiver in series with it does not1 the other one cannot be open1 and therefore1 must be short-circuited4 ,transmitter out of ,circuit1 but ,hearing not ,entirely ,cut ,out4 ,may be caused by3 #a4 ,open in green strand of desk stand cord1 transmitter or transmitter wiring4 #b4 ,transmitter short-circuited4 #c4 ,red and white strands of desk stand cord crossed together4 #a4 ,no hook clicks1 transmitter entirely dead1 but can hear induction on the line1 and can hear the effect of short-circuiting the line at the top of the bell indicates an open4 ,locate by connecting one terminal of your head receiver to the ,l#a post1 and feeling with the other terminal successively on the several points of the transmitter circuit from the ,l#b post to the hook2 as soon as you pass the open you will cease to get battery through the head receiver4 #b4 ,strong hook clicks1 transmitter entirely or nearly dead1 but can hear induction on the line and the effect of short-circuiting the line at the top of the bell1 indicates transmitter short-circuited4 ,open at the transmitter and put your head receiver in series to see whether the trouble is a short-circuit inside of the transmitter head1 or a cross of the transmitter cord or the green strand of the desk stand cord with the frame of the desk stand4 #c4 ,two hook clicks1 but the transmitter dead and cannot hear induction on the line1 and cannot hear the effect of short-circuiting the line at the top of the bell1 and bell rings poorly or not at all1 indicates red and white strands of the desk stand cord crossed together which short circuits the receiver while the hook is up4 ,disconnect the strap at the top of the bell1 and test as previously directed from the ,g post to the ,l#b post2 if you get battery the cord is crossed4 ,transmission ,poor4 ,may be due to3 #a4 ,transmitter packed or otherwise bad4 #b4 ,red strand of desk stand cord1 primary1 or hook contact open 7in which case the hearing will also be poor74 #c4 ,primary or secondary reversed4 #d4 ,primary and secondary crossed together 7this will also affect the hearing74 #e4 ,high resistance in the line or instrument4 #a4 ,when a transmitter is believed to be packed1 call the wire chief1 being very careful not to shake it up or jar it1 and get him to note the way it transmits2 then shake it up thoroughly1 and see what the effect is on transmission4 ,when a transmitter is suspected of packing but you fail to catch it in the act1 you can sometimes pack it by blowing gently into the mouth piece for a minute or so2 but in making this test be careful not to condemn a good instrument1 as almost any transmitter is liable to a certain amount of packing1 and will come up stronger immediately after having been shaken up4 ,when a transmitter is suspected of being otherwise defective a sure test can be made by temporarily swapping faces with some other instrument that is all right4 #b4 ,only one hook click and weak side tones indicate primary or red cord open4 ,connect one terminal of your head receiver to the ,l#b post and test with the other successively on the ,l#a post1 ,no4 #a and ,no4 #b terminals of the induction coil1 red cord post in desk stand1 hook spring1 and hook2 as soon as you pass the open you will not get battery4 #c4 ,examine #a and #b1 and #c and #d of the coil to see that they are not reversed1 that is1 see that the numbers of the coil terminals correspond with the numbers of the lugs that they connect to4 ,if the coil is reversed internally1 so that the numbers correspond but nevertheless one of the windings is wrong1 it can only be detected by the man at the other end4 ,call up the wire chief or go to another instrument yourself and listen to the transmission from the suspected instrument2 if the coil is reversed the transmission will be muffled4 ,prove by reversing either the primary or the secondary1 which should clear the trouble4 #d4 ,test as previously directed for primary and secondary crossed together4 #e4 ,get the wire chief to test the resistance of the line1 or test it yourself as follows3 ,bridge your lamp on at the top of the instrument1 the lamp will burn rather dimly on an ordinary line1 very dimly if it is a long line1 or an extension line from a private branch exchange with a high resistance drops and retardation coils4 7,in the latter case the test can be made better after the operator has plugged up the line47 ,next connect your line in series with the instrument1 take the receiver off the hook1 and compare the brightness of the lamp while the instrument is in circuit1 and while it is cut out by short-circuiting the ,l#a and ,l#b posts4 ,if there is much difference noticed there is a high resistance in the instrument4 ,forty ohms is a fair average for the resistance of a central battery instrument1 but it may be higher or may be lower1 it may run below #cj ohms4 ,about #af ohms of this is in the primary and the rest is in the transmitter4 ,illustration3 ,fig4 #b4 ,to prove that there is no resistance in the soldered connections or hook contact1 short-circuit both the primary and the transmitter2 this should cut out all of the resistance and completely short-circuit the instrument1 so that you will get no battery from ,l#a to ,l#b posts when the hook is up4 ,the resistance of a #bd volt test lamp is somewhere about #djj ohms cold and #bdj ohms hot4 ,hearing ,poor4 ,may be due to3 #a4 ,receiver bad4 #b4 ,receiver cord or white strand of desk stand cord bad4 #c4 ,condenser open4 #d4 ,primary and secondary crossed together4 #e4 ,primary short-circuited4 #f4 ,secondary short-circuited4 #g4 ,high resistance in secondary circuit4 ,there will be two hook clicks with any of the above troubles1 but one of the clicks may be cut down more or less4 #a4 ,examine the receiver for dented diaphragms1 8whiskers0 on the magnets1 magnets too close to diaphragm1 or magnets weak2 test by putting your head receiver in series with it and comparing the hearing4 #b4 ,to test the receiver cord and the white strand of the desk stand cord1 put battery through them and listen in the receiver for a cut out or scratchy sound while you shake them4 ,short-circuiting the condenser with a test cord puts battery through the receiver and its cords when the hook is up4 #c4 ,if the condenser is open the ringer usually will not ring1 but sometimes you can ring through a condenser that you cannot hear through at all4 ,test by short-circuiting it with a test cord4 #d4 ,primary and secondary crossed together will usually short-circuit the ringer and prevent your getting a ring4 ,test as previously directed4 #e4 ,if the primary is short-circuited bridge your head receiver around it2 you will get no click when the hook comes up1 and no side tones4 ,if the primary is all right you will get both clicks and side tones in your head receiver4 #f4 ,a short-circuited secondary can be tested by exactly the same method as is given above for testing the primary4 ,the above tests work very well if the primary or secondary is completely or nearly short-circuited1 but if the short circuit is only partial it is very hard to detect4 ,if you are in doubt1 change the bell temporarily for another bell that is all right or change the induction coil1 and compare results4 #g4 ,to test for a high resistance in the secondary circuit1 put battery through it by short-circuiting the condenser with a test cord while the hook up1 then listen in the receiver while you short-circuit successively the receiver hook contact1 the two sides of the receiver cord1 the white strand of the desk stand cord1 the wiring from receiver cord to secondary1 from secondary to condenser1 and from condenser to ,l#b1 and the secondary itself2 when you short circuit out any part of the circuit that contains resistance1 such as the secondary itself1 more battery will flow through the receiver1 giving you a click4 ,an instrument in which the ringer is not connected1 will1 of course1 give but one hook click4 ,reversals in the connecting up of desk stand cords may cause only one hook click or poor hook clicks1 poor transmission1 poor hearing1 transmitter nearly dead1 etc41 according to the combination in which the three strands of the cord are connected4 ,if the ground side of the line is open outside the set may be put in temporary service by working to a local ground4 ,if the induction coil is bad1 temporary service can be given1 if necessary1 by putting the transmitter and receiver in series1 and properly poling the receiver4 ,,chapter ,,ii4 ,,two ,,party ,,line4 ,no4 #a ,set4 7,the battery side of the line goes to the ,l#b post47 ,gives two hook clicks1 and can be tested in very much the same way as a straight set1 but the following points should be remembered3 on sets that ring to ground an open ground will1 like ringer open1 cause the bell not to ring and only one hook click4 ,resistance in the ground may cause poor ring4 ,reversal of the three wires on top of the bell may cause only one hook click1 bell not to ring1 and transmitter nearly dead4 ,transmitter very poor may be caused by the ground side of the line being open outside4 7,you can still call the operator and talk1 with difficulty through the ringer and ground47 ,no4 #b ,set4 ,gives but one hook click1 but otherwise can be tested in very much the same way as a straight set4 ,remember the following points3 ,on sets that ring to ground3 ,ground open will prevent bell from ringing4 ,resistance in the ground may cause poor ringing4 ,a ground on the ground side of the line may cause the bell to ring poorly or not at all by taking the generator current off to ground before it reaches the instrument4 ,condenser short-circuited will not only put a ground on the ground side of the line through the ringer1 but on exchanges which use pulsating current for ringing will also cause bell to ring poorly or not at all4 ,reversals of the three wires on top of the bell may cause two hook clicks1 bell not to ring1 and transmitter nearly dead4 ,on two-party sets1 to find reversals of the wires at the top of the bell1 trace out the wire to the protector1 or else find out with your head receiver which one of the three wires is alive to both of the others1 or to an independent ground4 ,this one is the battery side of the line4 ,to test for reversal of the ground wire with the ground side of the line1 bridge your head receiver from an independent ground to the two doubtful wires successively4 ,you will get induction on the line wire1 and none on the ground wire4 ,or1 bridge your receiver from the battery side of the line to the other two wires successively2 the one that gives the most induction in this case is the ground wire4 ,or again1 test by bridging your lamp from the battery side of the line to the other two wires successively4 ,if the ground is good1 bridging to it will give a brighter lamp than bridging to the ground side of the line2 only a little brighter if the line is short1 much brighter if the line is long4 ,the above is also the way to test for a poor ground4 ,the resistance of the ground return back to the central office should be less than the return through the cable1 therefore the lamp should burn brighter on the ground wire than on the ground side of the line2 very little brighter if the line is short1 much brighter if the line is long4 ,an extension bell open will prevent the main bell from ringing1 just as in a straight set4 ,test by running a temporary ground1 or by short-circuiting out the extension bell4 ,if you are in doubt when testing a two party set1 disconnect the ground wire and strap the bell1 making it a straight set temporarily1 and then test the ringing1 transmission1 and hearing4 ,a straight set will respond to all rings1 direct1 two-party1 and four-party4 ,if on a two-party set the ground side of the line is open outside1 temporary service may be given1 if necessary1 by working to the local ground4 ,if the ground is open1 temporary service can be given1 if necessary1 by converting to a straight set2 but in this case the bells will respond to both calls4 ,if second instrument is properly poled and bell rings when first station is being called1 the trouble is probably due to party at first station taking his receiver off the hook before the operator has stopped ringing1 and vice versa4 ,,chapter ,,iii4 ,,four-,,party ,,set4 7,diagram ,no4 #c47 ,tests of the transmitting and hearing circuits can be made in very much the same manner as in a straight set4 ,on account of the relay coil being bridged between ,no4 #b and ,no4 #c terminals of the induction coil1 a four-party desk set1 if in perfect order1 will give two hook clicks1 no matter how it is poled4 ,to make a perfectly sure test for primary and secondary crossed together1 it is necessary to disconnect one terminal of the relay winding2 then with the receiver on the hook1 test from the ,l#b post to the secondary with your head receiver2 if you get current there is a cross4 ,reversals of the three wires at the top of the instrument may cause a variety of troubles1 just as in the two-party sets4 ,ringing ,circuit4 ,relay3 ,failure of the relay to come up when the operator rings may be caused by3 ,condenser open4 ,relay short-circuited or open4 ,hook contacts1 or red and white strands of desk stand cord1 or primary and secondary of induction coil crossed together4 ,primary open4 ,trouble at central office4 ,test just as though it was a straight set except when testing for relay short circuited1 or for a cross between primary and secondary1 7in which case you must open one terminal of the relay winding1 as previously directed72 and except when testing for relay open1 which you can do by bridging your head receiver from ,l#b post to ,no4 #b and ,no4 #c terminals of the induction coil successively2 you should get strong battery on ,no4 #b terminal1 if the relay is all right and a strong condenser discharge when you make contact1 but a weak battery click when you break contact1 on ,no4 #c terminal4 ,a ground on the ground side of the line may also prevent the relay from operating1 by carrying the generator current off to ground before it reaches the instrument4 ,if the relay is held up1 usually the lamp is kept burning at the central office also1 and this means that current is flowing from the central office over the battery side of the line1 passing through the relay winding1 and returning to the central office over the ground side of the line1 or through the ground wire and ground4 ,this condition may be due to3 #ast4 ,winding of relay crossed with frame4 ,test by disconnecting the 8,a0 or 8,b0 terminals of the ringer from ,l#b which should release the relay4 #b;d4 ,as in the case of current through the ringer of a straight set1 the trouble may be caused by receiver contact of hook not breaking1 white and green strands of desk stand cord crossed together1 condenser short-circuited4 ,test as though it was a straight set4 ,illustration3 ,fig4 #c4 ,if the relay vibrates continuously the winding is probably crossed with the frame4 ,to find out whether this is the case1 disconnect the ground wire1 which should stop the vibrating4 ,if the relay 8jumps0 while the operator is ringing1 instead of pulling up and staying up as long as the ringing current continues1 the relay may be weak1 due to a part of the winding being short-circuited out1 or to some other cause2 or there may be too many bells and relays on the line1 so that1 owing to the resistance of the line1 not enough generator current will flow over it to divide up and give each bell and relay a proper amount of current2 or there may be a slight ground on the line1 which carries off a part of the ringing current4 ,to prove that a relay is all right3 #a4 ,short-circuit the condenser2 this should hold up the relay1 by putting battery current through it4 #b4 ,prove that the spring contact is not crossed with the frame as follows3 ,disconnect 8,a0 and 8,b01 then connect the frame of the relay to battery with a test cord1 and bridge from the spring contact to ground with your head receiver2 if you get no current there is no cross4 #c4 ,prove that the winding is not crossed with the frame as follows3 ,disconnect 8,a0 and 8,b0 and then test with your head receiver from the frame to the ,l#b posts2 if you get no battery there is no cross4 ,ringer3 ,if the relay comes up1 but the bell does not ring1 the trouble may be due to3 ,ringer poled wrong4 ,bias spring too tight or too loose4 ,ringer open4 ,ground open4 ,ringer short-circuited4 ,bridging your head receiver across the ringer while the operator is ringing will show whether or not you are getting generator current on the terminals of the ringer winding2 going in series at the 8,a0 and 8,b0 terminal will show whether or not you are getting current through the ringer4 ,to prove whether a ringer is open or not1 connect 8,a0 to battery1 hold the relay closed1 and then test from 8,b0 to ground with your head receiver2 if you get no current the circuit is open2 prove that the open is in the ringer itself by testing direct from the two terminals of the winding successively4 ,the ground can be tested in the same manner as on a two-party set4 ,to prove that the ringer is short-circuited1 connect 8,a0 and 8,b0 across the line1 close the relay contact1 and bridge across the terminals of the ringer winding with your head receiver2 if you get no click the ringer must be short circuited2 check this test by putting your head receiver in series with the ringer1 while it is connected across the line1 and closing the relay contact2 this should give you a strong click if the ringer is short-circuited4 ,bell ringing weak may be due to3 ,poor adjustment of armature4 ,poor adjustment of bias spring4 ,pivot screw too loose or too tight4 ,clapper rubbing on guard4 ,wiring interfering with clapper stem4 8,whiskers0 on magnet head4 ,magnet head sticky or gummy4 ,polarizing magnet weak4 ,one or both coils of ringer partially short-circuited4 ,too many bells and relays on the line4 ,ground on one side of line which takes part of the generator current off to ground before it reaches the instrument4 ,trouble at central office4 ,earth currents4 ,to test for earth currents bridge your head receiver from the ground side of the line to the ground2 you should get no current2 if you do get current you will probably find that it varies continually1 being due to trolley cars2 report the matter to the chief inspector4 ,in making this test be sure that the line is not in use2 if the receiver is off the hook at any station on the line you will get a false test4 ,earth currents very often cause bell troubles on suburban stations1 particularly those that lie near to trolley lines2 but in the city1 earth currents are seldom noticeable4 ,false rings may be caused by3 ,very strong earth currents4 ,one coil of ringer short-circuited4 ,if a biased ringer has one coil short-circuited1 then when it is poled for either #ast or #b;d stations it will respond to both rings2 and likewise when poled for #c;d or #dth stations it will ring with either current4 ,in the bell diagram ,no4 #c you will see that 8,b0 connects to the spring contact of the relay1 the frame of the relay connects to the biased side of the ringer1 and the unbiased side of the ringer connects to 8,a40 ,in the older bells1 8,b0 connects direct to the biased side of the ringer2 the unbiased side of the ringer connects to the spring contact of the relay1 and the frame of the relay connects to 8,a40 ,therefore1 in connecting an extension bell to a set that has no extension bell binding posts1 connect one side of the wire to the frame screw of the relay1 under the bottom of the set1 and the other side to the post at the top of the bell that 8,a0 connects with4 ,or solder one of the extension bell wires to the spring contact of the relay1 and connect the other to the post at the top of the bell that 8,b0 connects with4 ,in every case the auxiliary bell must be connected across the terminals of the ringer without being bridged around the break of the relay4 ,pole the extension bell by reversing the wires either at the bell or at the set4 ,ringer ,adjustments3 ,in adjusting a biased ringer find out the two points where the bell ceases to ring on account of the bias spring being too tight and too loose1 and adjust the spring half way between these points4 ,to locate them1 slack off the bias spring until it has no tension at all1 and then get the operator to ring while you tighten up the spring1 and note the point at which the bell commences to ring2 continue to tighten the spring until the bell ceases to ring2 by making the adjustment half-way between these two limits1 you will have a margin both ways1 so that if the generator rises a little above or falls a little below its proper voltage1 the bell will still ring4 ,the little set screw in the yoke at one end of the armature should be adjusted so as to hold the opposite or bias spring end of the armature a little away from the head of the magnet core2 #j4jb of an inch1 which is a little less than the diameter of a ,no4 #bb cross-connecting wire1 8,in every test use a little judgment40 ,,chapter ,,iv4 ,,how ,,to ,,test ,,for ,,and ,,clear ,,troubles ,,in ,,private ,,branch ,,exchange ,,switchboards4 ,station can't call3 ,when a station can't call1 the trouble may be due to the line being open1 or too much resistance in the line2 or to the signal being open1 or short-circuited1 or stuck4 ,short-circuit the line in the back of the switchboard or at correcting frame2 if the signal does not operate plug up the jack with a plug and see if the cord signal will operate2 if it will not the open is between the frame and the springs of the jacks if the cord signal will operate1 the trouble is back of the jack springs1 and may be an open1 or it may be that the drop is short-circuited or stuck4 ,test with a receiver or lamp1 if you get good battery on the locknuts but can't throw the drop1 it must be short-circuited or stuck2 if you get no battery there is an open2 short-circuit the inner contacts of the jack1 and if this brings up the signal the open is in the jack2 take the jack out and repair it4 ,if short-circuiting the inner contacts will not operate the signal1 the same may be open2 test from the ground strap of the jack direct to the signal terminals2 if the signal tests all right the wire leading from one side of the signal to one inner contact of the jack must be open2 prove by short circuiting same out with a test cord4 ,if there is battery on the jack but the signal won't come up1 push gently against the back of the armature of the signal with a tooth pick until it starts to raise2 you can tell by the feeling if it is at all stuck4 ,another good way to tell whether the signal sticks is to go to the station and hold the receiver to your ear and then allow the hook to raise4 ,when the signal flies up it can be heard in the receiver as a sort of 8tremble40 ,this 8tremble0 should take place the instant the hook comes up2 if it is delayed1 the signal must be sticking4 ,this test can also be made from the frame with a head receiver4 ,to test whether the signal is short-circuited1 see how brightly your lamp burns when connected at the frame and then compare with other signals which are all right2 a signal which is wholly or partly short-circuited will have less resistance than the others1 and the lamp will burn brighter4 ,if the signal comes up from the frame but will not come up from the instrument1 the line may have too much resistance and the signal will have to be adjusted so as to be more sensitive4 ,if a station on a long line has trouble calling at times1 there may be a poor connection in the circuit which varies2 or it may be that the signal fails to work only when the board is busy1 due to the drop in voltage on the battery feed when much current is being drawn from it2 the signal will have to be adjusted more delicately or the battery feed increased4 ,illustration3 ,fig4 #d4 ,station ,signal ,stays up3 ,the line must be either crossed1 or grounded on the battery side4 ,plug into the jack with a detached plug and cord1 and then test successively on the ring and tip of the detached cord with a receiver or lamp that is connected to battery4 ,this will show if there is a ground on either side of the line4 ,if both sides test clear of grounds1 there must be a cross2 to prove this1 ground the tip side by holding the tip of the detached cord on the tip of any other plug2 if there is a cross the ring side will then test grounded4 ,to locate the trouble1 open the line successively at the frame cable box instrument1 etc41 and note the effect on the signal4 ,in testing with a receiver for grounds or crosses on lines1 you should be guided by the click when you break contact2 otherwise1 you are likely to be deceived by the electrostatic capacity of the line and condenser in the instrument4 ,in such tests you may get a strong click when you make contact1 particularly if the line runs through a cable1 and you may also get plenty of induction on the line2 but if you do not get a click when you break contact1 there is no current flowing through your receiver1 and therefore the line is clear4 ,if plugging into the jack does not restore the signal1 the trouble must be a cross in the jack1 or in the signal itself4 ,examine the jack lugs1 and also the inner end of the signal winding1 which may be in contact with the iron mounting strip4 ,if the trouble is not here1 disconnect the wire going to the jack from the signal2 this will show whether the trouble is in the signal itself4 ,if the sleeve of a station jack is grounded1 the cord circuit relay will operate when you plug into the jack1 and cut the battery off of that pair of cords4 ,touching the tip of a plug to the sleeve of a station jack with the listening key thrown will show if the sleeve is grounded by giving a click in the operator's receiver1 the same as touching the sleeve of a trunk jack will do4 ,the ground may be due to the sleeve being crossed with the sleeve of a trunk jack1 or crossed with the sleeve of a station jack that is connected to a trunk jack2 or it may be between the sleeve and the inner contact of the jack on the ground side4 ,battery ,feed and ,trunks3 ,the battery feed and trunks must always be poled properly4 ,to test the poling of the feed1 run a temporary ground and touch it to the ring of the back plug4 ,if this does not bring up the cord signal the feed is poled wrong1 and the feed and ground will have to be reversed4 ,to test the poling of a trunk1 plug into the trunk-jack with the front plug of any pair1 say ,no4 #a pair2 then touch the tip of any other plug to the ring of the back plug of ,no4 #a pair2 if this does not bring up the cord signal on ,no4 #a pair the trunk is poled wrong4 ,one of the troubles caused by the wrong poling of a trunk is that if the operator plugs in to answer the trunk while she has another listening key thrown1 her transmitter goes dead4 ,if operator at the central office can't throw a trunk drop at a private branch switchboard the same may be open1 or the condenser may be open4 ,bridge a receiver across the drop2 if you can get a good ring in the receiver the condenser is all right and the drop is probably open4 ,if you can't get a ring across the drop1 short-circuit the condenser2 if this puts battery through the drop and brings it up1 the condenser must be open4 ,if a cord circuit relay fails to operate on any trunk1 the ground strap may be broken off of the jack4 ,plug up the jack1 then touch the butt of the plug with the tip of a plug of any other pair2 if this operates the relay1 it shows that the sleeve of the jack did not operate it1 and therefore the sleeve connection must be open4 ,the sleeve connections are often taken off purposely on tie trunks4 ,if the operator complains of central cutting her off1 some of the holding coils may be open4 ,instructions are given further ahead for testing them4 ,if plugging up a trunk causes the cord circuit relay to vibrate the battery feed or ground must be open4 ,if the line or cord signals fail to come up properly the battery feed may be weak2 this may be due to a poor connection in the feed or ground1 or to one of the conductors of the feed being open1 or to the feed being grounded through resistance4 ,bridge a lamp across the feed2 it should burn brightly if no current is being used on the switchboard4 ,throw a listening key1 or bridge a receiver across the feed2 if this puts the lamp out1 or dims it excessively1 the feed or ground has a high resistance on it1 or some of the conductors are open4 ,disconnect the conductors one at a time at the table head or protector1 and see if each one will light your lamp properly4 ,if the lamp burns dimly when no current is being used on the switchboard1 the feed is probably grounded through resistance2 disconnect it from the switchboard and test2 if it still gives a dim lamp disconnect at the protector and test again to prove whether trouble is inside or outside4 ,the amount that a lamp bridged across a battery feed will be dimmed by throwing a listening key or bridging on a receiver depends upon the resistance of the feed4 ,if the feed is very long the lamp will be dimmed very much2 if the feed is short or consists of several pair1 the lamp will be dimmed but slightly4 ,each inspector should become familiar with the behavior of the battery feeds on all his important boards2 he should know how the lamp burns when the board is idle1 and how much it is dimmed when a certain number of connections are up1 so that in case of trouble he can tell at once by a lamp test whether the feed is ,o4,k4 or whether it has too much resistance1 or is partially grounded4 ,troubles ,causing ,bells to ,ring4 ,a swinging open or swinging ground on the battery feed causes the bells at the stations to ring by charging and discharging the condensers4 ,generator feed crossed with the battery feed causes bells to ring4 ,examine wiring and generator contacts at ringing keys4 ,where the spring of a station jack does not break from1 or is crossed with the inner contact1 all bells may be rung by ringing on that jack with power generator1 which is always grounded on one side4 ,if the outer contact of a ringing key makes before the inner contact breaks1 all bells may be rung when that key is used1 by the generator current passing down through one side of the retardation coil to the battery feed4 ,cord ,circuit4 ,tip and sleeve crossed causes vibrating relay on that pair4 ,tip and ring crossed short-circuits the cord4 ,ring and sleeve crossed causes relay to vibrate when ring and tip of plug are short-circuited1 or when the plug is put in a station jack with the station receiver off the hook1--sometimes merely throwing the listening key on that pair will make the relay vibrate4 ,touching ring to tip and tip to ring of the two plugs of any pair should give a spark1 and the signal should also come up when the ring of the plug is touched with a tip4 ,if there is trouble1 take any other plug which is ,o4,k4 and test the bad pair2 if both rings or both tips fail to give a spark1 there is probably an open at the relay1 the retardation coil1 or the soldered connections on the listening key4 ,if only one cord tests open1 and the other one of the same pair tests ,o4,k41 ring on the bad cord and feel for generator current in the plug4 ,if you get current1 the open must be at the inner contact of the ringing key2 or1 it may be in the cord signal4 ,if you cannot get generator on the plug1 the open is in the cord4 ,to locate any open that effects both cords1 test successively on inner contacts and swinging contacts of relay1 inner and outer lugs of retardation coil1 and swinging contacts of listening key1 you should get battery across all of these points4 ,if either cord of a pair is short-circuited it short-circuits both cords and you will not get proper sparks when touching ring to tip and tip to ring but you may get small sparks4 ,also the operator's transmitter will be dead on that pair of cords and if you test with a receiver or lamp you will get little or no battery between the ring and tip of either plug1 but will get battery of about half the proper strength from either the ring or the tip of either plug to either the ring or the tip of a plug of any other pair4 ,you can also tell whether a cord circuit is short-circuited by bridging your receiver around one half of the retardation coil2 if there is a short-circuit1 part of the current that is flowing around through the coil will go through your receiver1 giving you a click4 ,to locate the short-circuit1 ring on the two cords successively1 and feel on the plugs for generator4 ,if both cords test clear1 the trouble must be back of where the circuit branches at the listening key2 disconnect successively at the relay1 the retardation coil1 and the listening key until you locate the trouble4 ,in most of the private branch exchange switchboards the battery goes first to the inner contacts of the relay1 then through the swinging contacts to the retardation coil1 and from the retardation coil to the swinging contacts of the listening key2 in other boards the battery goes first to the retardation coil1 then through the relay contacts to the listening key4 ,from the listening key it goes to the inner contacts of the ringing key1 and from the swinging contacts of the ringing keys to the cord fasteners4 ,if a cord circuit is open at the relay or retardation coil1 it will still work on a trunk connection1 the trunk supplying the battery1 if the central office is common battery system4 ,lamp tests of the retardation coils and cord signals can be made by bridging a lamp across the bus-bars and then short-circuiting the tip and ring of every cord successively4 ,each one should dim the lamp the same amount2 if one cord dims it less than the others1 it shows that there is more resistance in that cord circuit--possibly a bad connection1 or a cord signal with too much resistance4 ,if one cord dims it more than the others1 there must be less resistance in that cord circuit1 probably one half of the retardation coil is short-circuited4 7,this test fails where there is a floater battery1 or a battery feed of very low resistance47 ,to prove that one side of the retardation coil is short-circuited1 short-circuit one of the plugs of that pair1 and then bridge a receiver successively around the two sides of the coil1 no click on one side should mean that that side was short-circuited4 ,a finer test can be made by bridging the lamp across the tip and ring of the cord1 and short-circuiting out the two sides of the coil successively2 each side should brighten the lamp exactly the same amount4 ,if one side brightens it more than the other1 that side has more resistance than the other4 ,unbalanced coils are usually noisy1 especially on long lines4 ,an unbalanced coil can usually be detected by simply listening on each pair of cords1 successively2 if the battery feed induction is stronger on one pair than on the other1 that pair is probably unbalanced4 ,in most boards the holding coil is bridged across the outer contacts of the relay4 ,in other boards one end of the coil connects to one swinging contact of the relay1 and the other end to the opposite outer contact4 ,to test the holding coil1 plug into a trunk jack with the back plug and throw the listening key1 which will bring up the cord signal1 then throw the listening key normal4 ,if the signal stays up the holding coil is ,o4,k41 if it disappears the holding coil circuit must be open4 ,the trouble may be that the relay contact does not close1 or the coil itself may be open4 ,test by plugging into a trunk with the back cord and then short-circuiting the holding coil2 if the cord signal comes up the holding coil must be open2 if it does not come up1 leave the short-circuit on the coil and bridge out the holding coil contacts of the relay4 ,when you bridge out the contact where the open is1 the signal will come up4 ,to test the relay on any cord circuit1 touch the tip of any other plug to the sleeve of either plug of that pair2 if this does not operate the relay the sleeve conductor of the cord may be open2 if neither plug of the pair will operate it1 the relay itself may be open2 test with a receiver or lamp4 ,touching the tip of one plug to the sleeve of the other plug of the same pair should make the relay vibrate4 ,to test a switchboard cord1 plug into the cord testing jack 7every board should have a testing jack connected to put battery direct on your head receiver7 and shake the cord1 and turn and shake the plug in the jack1 while you listen in the operator's receiver for any cut-off or bad connection4 ,do not have any listening key thrown while you are testing switchboard cords2 also see that the operator's receiver is poled so that the current from the cord strengthens the magnetism instead of weakening it otherwise you will not get a sensitive test4 ,the tips and rings of the plugs must be clean1 or else they will be scratchy4 ,be very careful that none of the plugs are bent or 8lopsided20 such plugs may work all right in some jacks and cut-off in others4 ,if turning a plug around in a jack causes a cut-off the plug should be condemned2 sometimes the jack may be at fault1 and the long spring will have to be given more 8set40 ,after changing switchboard cords1 always test the new ones for opens1 short-circuits and reversals4 ,cross-,talk3 ,solder dropped on the cord fasteners1 or a cross at the keys1 may connect two different cord circuits together1 and cause cross-talk between them4 ,retardation coils may be crossed with their cases1 and cause cross-talk by the cases being in contact4 ,condensers on trunk drops may make two trunks cross talk in the same way4 ,test by bridging a receiver from the case of the suspected coil or condenser to battery and to ground successively4 ,there will be no click if the case is clear4 ,unbalanced retardation coils1 or a weak battery1 may also cause cross-talk4 ,a listening key that does not break contact on both sides will cause cross-talk when that pair of cords is used2 if with all keys normal you get a click in the operator's receiver when you touch the tip of any plug to the frame of the operator's transmitter1 the operator's circuit is in contact with some cord circuit at the listening key4 ,to find out which key1 see that all keys are normal and then vibrate the relay on each pair of cords successively by touching the tip of one plug to the sleeve of the other2 when you come to the pair where the cross is1 the buzz will be heard plainly in the operator's receiver2 on the others it will be heard very faintly4 ,operator's ,set3 ,to test the receiver cord1 put a plug in the cord testing jack1 this puts battery through the receiver1 and by shaking the cord any fault will show up provided the receiver is poled properly4 ,do not have any listening key thrown when making this test4 ,to test the transmitter cords1 throw up any listening key and listen in the operator's receiver while you shake the cords4 ,to locate an open in the operator's primary circuit1 throw any listening key1 and then bridge a receiver successively around the several parts of the circuit1 that is1 the #bjj ohm resistance coil1 the transmitter1 7including its cords71 and the primary4 ,when you bridge around the part that is open1 you will get a click in the receiver4 ,to locate an open in the secondary circuit1 short-circuit out the condenser so as to get battery through the circuit and then bridge around the receiver and secondary with a receiver until you have found where the open is4 ,buzzer and ,buzzer ,relay3 ,if a buzzer which works off the battery feed fails to operate at times1 although the buzzer relay comes up1 probably it is not sensitive enough1 and when the board is busy the battery feed it not strong enough for it4 ,adjust the buzzer more delicately and test it when the board is idle and when it is busy4 ,to make a board busy artificially1 bridge a head receiver across the bus-bars2 that is equivalent to several pairs of connections being up4 ,if some of the station lines are very long1 the buzzer relay may fail to come up on them1 or come up so weakly as not to make good contact4 ,to cure this1 adjust the relay more delicately4 ,if a trunk drop won't operate the buzzer relay when the key is up1 the trouble is probably at the night bell contact of the drop4 ,if none of the trunk drops will operate it1 the relay may not be adjusted delicately enough1 or the #ejj ohm resistance coil may be open4 ,bridge around the trunk drop contacts with a receiver4 ,if you get no battery the coil must be open2 prove by bridging the coil out and repeating the test4 ,a heavy ground on the ground side of any station line will prevent the buzzer relay from coming up by shunting it out4 ,a light ground will sometimes cause trouble on the long lines only4 ,a short-circuited condenser or a slight leak across any line or lines1 may hold up the buzzer relay4 ,test the lines for crosses and grounds1 as previously instructed4 ,if the buzzer relay comes up at times when no signal is up1 the trouble may be due to some station on a long line trying to call1 and the signal not sensitive enough to come up4 ,general4 ,to prove that a board is perfectly clear1 disconnect the battery feed from the negative bus-bar1 and put a lamp or receiver in series4 ,if you get no current then all the lines are free from crosses1 they are free from grounds on the battery side1 and the other circuits in the board are also clear of crosses4 7,this test can only be made when there are no connections up1 no listening keys thrown1 and no stations calling47 ,to prove that the ground sides of all the lines are clear1 disconnect both the feed and ground wires from the bus-bars1 and then test through a lamp or receiver from the battery feed to the ground bus-bar2 if you get no current1 the lines are all clear on the ground side4 ,,inspection ,how to ,inspect ,subscribers' ,instruments4 #ast4--,ask the subscriber if his instrument works properly and repair any defect that he reports4 ,also be sure the instrument is securely fastened to the wall or desk4 #b;d4--,clean and polish the varnished and nickeled parts of the instrument2 open the bell and see that it is clean and in proper condition inside1 and that the hook1 ringer1 and other moving parts work properly and clean the hook contacts with paper if they are dirty or make a scratching noise in the receiver4 #c;d4--,see that all binding post connections are tight1 test all cords2 in testing the receiver cord1 put battery through it by short-circuiting the condenser2 change any cords or other parts that are defective or unsightly4 #dth4--,clean the receiver outside1 remove the cap and examine the diaphragm and clean the magnets2 in cleaning the magnets rub them off with your coat sleeve or a clean rag rather than with your hands1 as the moisture from your hand will cause them to rust4 #eth4--,examine the adjustment of the bell and test by getting a ring from the operator1 at the same time test the transmission and hearing4 ,test all extention bells by getting a ring from the operator2 inspect all other apparatus1 such as hand generators1 switches1 local batteries1 fans booths and signs4 ,it is important that signs should be kept in good condition2 dirty or unsightly ones should be cleaned or ordered changed1 and you should be particularly careful to see that all signs are securely hung4 #fth4--,inspect all wiring1 including the leading in wires1 the inside line wires1 the battery wires and the ground wires2 also the protection1 the fuses1 any extention bells and also see that the ground is properly made that it is connected to the proper pipes4 ,if a gas pipe has been used see that the bridge on the meter has not been disturbed since the last inspection4 #gth4--,see that the protector contains the proper kind of fuses1 and if it can be gotten at readily2 examine the connections and remove the cap from over the carbons to see that no one has left the carbons out4 #hth4--,if a subscriber applies to you to have an additional instrument installed1 take his name and address and turn them in to the manager2 if he wants his telephone moved or disconnected1 or circuit number changed1 or extention bell or sign installed1 request him to call up the managers office4 ,if he complains of poor operating service1 or of interference by other subscribers on his line1 refer him to the manager4 ,if he complains of some trouble that is in the outside line or at the central office1 report the matter to the chief inspector at once4 #ith4--,in making recommendations1 state briefly but plainly just what you want done and give the reason why4 ,if the installer has done any work at the station since your last inspection1 and has failed to leave it in proper condition1 accompany the recommendation that you make with a written complaint4 ,making ,first ,inspections of ,new ,installations4 ,in inspecting a new installation1 or an instrument that has been moved or changed since your last inspection1 or in going over your instruments for the first time1 the inspection should be made more carefully than at other times4 ,ask the subscriber if he has any extention stations1 extention bells or other apparatus attached to his instrument1 also look out for them while you are making the inspection and tracing out the wiring4 ,open the desk stand and see that all the locknuts are tight and soldered connections are perfect4 ,examine and shake all soldered connections in the bell4 ,trace out all of the wiring and be sure to see that all splices are properly soldered and taped and see that no tacks are driven in the splice4 ,make a lamp or receiver test of the protector and the instrument ground1 to see that they are good and have no resistance4 ,see that the protector is securely fastened1 that the connections are all tight1 that the fuses and carbons are of the proper kind1 and that the micas have the open side down4 ,test the fuses for loose connections inside1 by bridging your head receiver across the binding post at the instrument end of the protector and listening for a cut-off1 while you shake and jar the fuses4 ,test all switches to see that they make all proper connections1 oil the hand generators and see that the bell clapper works freely4 ,see that the specifications have been complied with in placing the protector and the instrument1 in running all the wire1 and in every other particular2 that the desk stand cords are cleated1 and protection cleats used where needed2 that desk sets give two hook clicks2 that snap switches are of the indicating type2 that the connections to all binding posts are neat and of proper length2 that the booth is clean and have plugs in all the screw holes2 that they have no broken glass and have linoleum on the floor1 and that the doors and latches all work freely4 ,see that the protector is placed so as not to be in the way of curtains2 that no damage has been done to the subscribers property2 that all apparatus has been installed so that it will not be in his way1 and will not be exposed to disfigurement1 damage1 trouble from dampness or rain1 etc41 that wire is run where it will be safe from injury1 dampness and wear2 in short1 see that the installation is done according to specifications in every respect4 ,see that the cut-in 7the wires from the pole to the house7 are properly made and are of the proper kind of wire4 ,,don',t ,,forget ,,that ,,your ,,reputation ,,as ,,an ,,inspector ,,is ,,at ,,stake4 ,,footnote #a ,where reference is made to 8hook clicks0 in these instructions1 the instrument is understood to be a desk stand1 wall sets are so connected as to give only one hook click on raising or lowering the hook4 ,when reference is made to the red1 white or green strand of the desk stand cord1 it is understood that the red goes to the hook1 the white to the receiver and the green to the transmitter1 using the standard ,western ,electric cord4 ,when reference is made to ,l#a1 ,l#b or ,g you will find them on diagram ,no4 #a or ,no4 #b4 ,when reference is made to 8,a0 or 8,b0 you will find them on diagram ,no4 #c4 ---------------------------- ,end of ,book ---------------------------- ,transcriber's ,note 7continued7 ,page #db - 8deskstand0 changed to 8desk stand0 7,open the desk stand7 ,page #dc - 8lineoleum0 changed to 8linoleum0 7have linoleum on the floor7 ,footnote - 8,g#a0 changed to 8,g0 7,when reference is made to ,l#a1 ,l#b or ,g7 ,the words 8extension0 and 8extention0 are used interchangeably throughout the book and have been left unchanged4 ,some missing punctuation and other minor typographical errors have been corrected without note4 ,the single footnote has been placed at the end of the book4