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INSTRUCTION BULLETIN
FOR
TELEPHONE REPEATER- Signal Corps, U. S. Army Order No. 12930 - Phila. - 42 FORT MONMOUTH SIGNAL CORPS PUBLICATIONS AGENCY FOR REFERENCE ONLY DO NOT TAKE FROM THIS ROOM • BY ORDER OF THE DIRECTOR n4- F't. Mon.- J2-4-43-5M--HQ ~~~~~~~~e_ MANUF ACTUBED BY !ntcrnational retepltone ~ J UNITED STATES OF AMERICA INSTRUCTION BULLETIN FOR TELEPHONE REPEATER TP-7 Signal Corps, U. S. Army Order No. 12930 - Phila. - 42 MANUFACTURED BY JJtterJtatioJta! retepltoJte .t J(adio ;tlfp. eorp. UNITED STATES OF AMERICA I October 15, 1942 CONTENTS Section Subj ect Page General ...... 2 Mechan ical Description 2. 1 l ~epeate r U nit ...... 2.2 Power U ni t ...... 2 2.3 !\ ssem b Ie d Units ---- -·- ·····················---·-·--- ········-········-- 2 3 Circuit D escription 3. 1 I ~ cpea ter Unit ...... 2 3.2 l)o wer Unit ...... 5 4 O peration 4.1 General ...... 5 4.2 ·Power Connections ...... 6 4.3 Line Connections ...... 7 4.4 Circui t Operation ...... 7 4.5 Monitori ng and Talking ...... 7 4.fi ~ ignalli ng ...... 8 5 Parts l ist 5. 1 T elephone Repeater TP-7...... 8 5.2 W93-22 T elephone Repeater U ni t...... 8 5.3 W93-23 Power Unit ...... 10 5.4 W93-21 Outer Case Equi pped with Spares ...... 11 5.5 W93-11 A. C. Mains Power Cable ...... 11 5.6 W93-12 Current Supply Cable ...... 11 LIST OF PHOTOGRAPHS AND DRAWINGS Figure Subject Page Repeater Unit without Dust Co ver (Back View)____ 12 2 Repeater U nit without Dust Cover (Front View).. 13 3 Repeater Unit ------'------14 4 Relay Rack Mounting of Telephone Repeater T P-7 15 Sa ] ower Unit 16 Sb Power Unit without Dust Cover______17 Ga Telep hone Repeater with Case Cover open______18 ob T eleph one Repeater with Case Co ver cl osed______19 7a Typical Four Wire Circuit______20 7b Transform er Connection s at the Vari ous Impedance Switch Positions ------21 8 Simplifi ed Schematic Diagram of Amplifier.______22 9 Co nn ec tions for Impedance Switches S-1 and S-2.. __ 23 10 Circuits of Equalization for E ach Position of Switch 24 11 Frequ ency Curves of Repeater and Cabl e______25 12 Schematic of Power Unit______26 13 Panels for Repeater Showing Cabl e Co nnections______27 14 Co nn ec tions for T alking and Monitoring ______28 15 Schematic Circuit of T elephone Repeater 1 P -7______29 TELEPHONE REPEATER TP-7 1. GENERAL Telephone repeater TP-7 is intended to use on fo ur wire Jin es either as a throug h or a termin al repeater. It is arranged f r portable field use or for mounting on a relay rack in an office. It consists essentially of two two-stage amplifi ers arranged o t hat the in puts and outputs can be switched to present either 300 ohm or 1200 ohm im pedance to the line as req uired or 600 ohm impedance w hen used a a terminal repeater. In order to compensate for variation of the transmission los w ith frequency over the lin e, an eq uali zer w hi ch can I e switched is provided. The switched positions make possible a fl at o·ain freq uency characteristic or one which slopes to compensate for diffe rent lengths of lin e. Each am pli fier has an operatin g gain of about 35 db at 1000 cycl es per second irrespective of the eq uali zer setting. Under normal opera ting conditions the re1 eater i capable of handling a power level of + 20 dbm. A power unit is provided, which suppli e the req uired power for operatin g the re1 eater from either the A. . mains or from a 12 volt battery with a 100 cycl e per second vibrator. In addition, a means is provid e I so that the power may be obtain ed from local 24- 130 v bat teri es. T he current drain s for these methods of supplyin g power are as foll ows: Power ·~t jJJJl ·y Voltage C~ot ?Tent A. C. (Line) 110 110 milliamperes A. (Lin e) 220 55 milliamperes Battery 12 1 ampere Office Battery 24 150 m iII iam peres Office Battery 130 20 milliamperes 2. MECHANICAL DESCRIPTION 2.1 Repeater Unit T he repeater unit compri ses a chassis type assembly 17" x 5% 6" x 3~" as shown in photographs F ig. 1 and Fig. 2. This chassis has mounted on it the co mponent parts of the two amplifiers and is enclosed in a metal dust cover, as hown in protograph F ig. 3. The location of the necessary gain controls, witches and terminals fo r making the con nections to the lin e. for operatin g the repeater are hown in the upper panel of the rack moun ted repeater a· in photograph Fig. 4. T he eq uipment fo r each ampli fier occupies one half the length of the chassis. T he e 1uali zer coil , input and output coil an l gain control with associated switches are mounted in this ·equence from either end toward the center. T he two tubes of each a mplifier are mounted in a w ell left and ri g ht of the vertical center lin e and are covered by a removable plate so that they are readil y accessibl e. A plug is mounted on th e bottom of the chassis for making the power connections by means of the special cable supplied with the repeater. 2.2 Power Unit The equipment for the power supply is as ·embled on a chassis similar in design to the repeater unit as shown in photographs F ig. Sa and Fig. Sb and in the bottom panel of Fig. 4. It contain s the power transformer, rectifier and fi ltering arrangemen ts for operatino" lhe heat ers and plates of the tubes in the repeater from A. . mains. W hen a 12 vo lt torage battery is the source of power, it i · used in conjuncti n with a 100 c. p. s. vibrator to energize the tran former feeding the recti fier. Under thi condition the heaters of the vacuum tubes are operated directly from the I attery. T erminals, fuses and switches arc mounted on the panel of the chassis assembly. A plug for connecting power to th e repeater is moun ted on the bottom of the chassis. 2.3 Assembled Units Both the repealer and the power unit have brackets at ll1c ends so that th ey can l.)e mou nted on a relay rack as shown in Fig. 4 o r in a case as shown in F ig. 6a. A wooden case is provid ed for mounting both the repeater unit and the power unit. This case is 20" x 8" x 9;;.;1." and is eq uipped with straps so that it is readily portable, as ·hown in photo graphs F ig. 6a and 6b . T he case with rq eater and power unit mounted in it weighs about 38 pounds. When the cover is opene l, lhe terminals, switches and co ntrols are exposed so that they are readily available f r making con nections and operation, as shown in photograr h Fig. 6a. The power from the power unit is ·upplied to the repeater unit by means of a cabl e with a socket on each end, which ma tches the plu g mounted on the uni t·. Two spare tubes, two spare fuses, a socket fo r connectin g the repeater to a 24 v - 130 v supply, a spare vibrator and a pare socket to fit th e plug marked A. ·.Main are mounted in the cover of th case. When the repeater and power unit are m unted together on a relay rack, the same cabl e with sockets on each end as is used with the case may be used for making the co nn ection to supply the power to the re peater unit, otherwise a longer cable between plugs will be required. In case the repeater is install ed where the office batteries are available for operatin a it, either on an emergency basis or in place of the power unit, a socket i provided which fi.ts the plu g in the repeater a nd can be wired so that the proper co nnections can be rea lily made to the batteries, as shown in F ig. 12. T his socket is mounted in the cover with the spare parts. 3. CIRCUIT DESCRIPTION 3.1 Repeater Unit The repeater unit consists of two amplifiers, with an equalizer for each and 3 position switches to change the gain frequency characteristic from Aat to different slopes to compensate fo r lin e conditions. Switches are also provided to chan ge the input and output impedance of the am plifi ers from 300 to 1200 ohms and to con nec t the input of one amplifier and the output of the other to a two-wire 600 ohm connection for ter minal use. The diagrams of Fig. 7b show the different arrangements pos sible when this repeater is connected on a four-wire line. 2 The two amplifi ers are identical in design. T he circuit of one is shown schemati call y in F ig. 8. The transformer T1A actuall y consists of a repeatin g coil and in put transformer contain ed in one case. The eq ualizer is designed to have a nominal im pedance of 600 ohms and is conn ected between the repeatin g coil and the in put transformer. The repeating coil has an im pedance ratio of 300:600 ohms between th e 1-3 and 6-7 windings and 1200-600 ohms between the 1-3, 4-5 wind in gs connected in series and the win ding 6-7. T he two halves of the 1-3 w inding and the winding 1-3 and 4-5 are accurately balanced so that the terminals 2 and 4 may be used as a phantom tap for throug h signaling at 20 c.p.s. T he pi-oper connections, de[ endin g on whether it is the two-wire sid e of a termin al repeater or on the impedance of the line fo r four-wire operalion, a re obtain ed by means of a 3 positi n switch shown schem aticall y in Fig. 9 as S-1. Position 1 conn ects two windings of the TlA input coil of amplifi er A to two w in dings of the T2B output coil of am plifier B ·o as to give a ·two way or hybrid coil conn ection. It will be noted th at: the windings 4-5 of each coil are conn ected in seri es opposing through a conden er so that transmi ssion from the two-wire line divides eqnall y between them. The currents induced in the windings 1-3 of each coil , which are conn ected in seri es aiding through the cond enser and 600 ohm resistance to fo rm the network circuit, are in opposite directions so that little or no energy i lost in the network depending on the bal ance 1 etween the 600 ohm resistance and the lin e impedance. The energy from the lin e i divided between the win dings 4-5 of TlA and T2B coil s so that one half is transmitted into the in put of the A amplifier and one ha lf into the output of the B amJlifier and is lost in the plate circuit. O n the other hand, for transmission coming from amplif1 er B, currents are in duced in the lin e and network circui ts through the windings 4-5 and 1-3 of the T2B coil. These currents Aow in to windings 4-5 and 1-3 of the Tl A coil in opJ osite directions so that no energy passes into am pliher A when th e terminal eq uipment is balanced by the network. O ne half the energy received is transmitted to the two-wire lin e and one half is lost in the network. For hybrid coil operation, the win lings 1-3 and 4-5 of each of the coil s TIA and TlB must be accurately balanced. The condenser in the lin e side of th e hybri d coil connection is r equired to block any direct current on the lin e and to provide phantom taps which are taken from each sid e of this cond en. er. This condenser is balanced in the network circuit by one of approxim ately eq ual value. In order to fa cili tate replacement, if one of these condensers becomes defective, they arc . elected in groups of approximately eq ual capacities and marked A, D or C, the eff ective one should be replaced from the group corre pond in g to the letter on the one replaced. If one of the same letter is not available, then both should be replaced with a pair from one of the other groups. Position 2 conn e ·ts the windings 1-3 of T l A and T2B coil s to the .1 input and output four-wire terminals resr cctively lo o-ive lhe 300 ohm impedance and co nnec t tap 2 in each ca ·e to the terminals marked l>h-In a ncl Ph-Out. l>osition 3 conn ec ts th e w indings 1-3 and 4-5 of each of the coil s in serie and to the input and output fo ur-w ire termin als to provide the 1200 ohm imr edan e. It also connects terminal 4 of each [ the coils to the terminal · Ph-In and ·1 h-Out. The input transformer has an impedance ratio to give 600 hm on the low side w hen terminated in t he 250,000 ohm potentiomcl r on the high side. This potentiometer is conn ected to the grid of the Vl.A (VT 198A) tube so that th e gain of the a mr lifi er can I c controll ed con tinuou ly in a range fr om 0 output lo a gain of abou t 35 db. The V 1A tube is resistance coup led to the V2A (VT 19 A) tube which, in lurn, i. conn ec ted to th e output transformer T2A terminals 8 a nd 9. Transform er T2A has a monitoring winding 6-7 which i · conn ected between a monitorin g terminal and ground. T erminal 6 i · a l. o connected throug h 11 ,300 ohm s to terminal 9, of the T l A tra nsform er, and lo 0 Tound through a 600 ohm resistance t give negati ve feed! ack in order to ·tabi li ze th e gain of th e repeater for variations in the perating voltao·es. T he impedance ratio of windings 8-9 and 1-3 r 8-9 and 1-3, 4-5 in series is such as lo give the optimum impedance termination f r the p late of the V2 tube when winding 1-3 i terminated with 300 oh ms or w inding 1-3 , 4-5 in seri es arc termin a ted in 1200 ohms. The windings 1-2, 2-3 and 1-3, 4-5 are accurately balanced so that coil taps 2 a nd 4 may be used as phantom laps for co nn ection to the corresponding terminals of the T1A or T2B transformer to byr as signalin g currents of 20 c.p.s. Dependin g on th e lin e impedance, th e proper impedance and tap f r the A OUT an I BIN am plifi er is selected by means of a two position switch, S-2. hown in Fig. 9, in the sam e manner as for A IN and B OUT, excer t that no two-wire conn ec tion i provid ed. Position 1 is for the 300 ohm and posi ti on 2 for th e 1200 ohm impedance. The biasin g voltages for the vacuum tubes are obtained from cathode resistan ces. The voltages at th e p wer terminals are 110 v for the input ur stage and 130 v for output stage when measured with a hig h resistance vo ltmeter and 12 v for two heaters in serie . H none of the element · of the equalizer were onnected, the over-all gain between the in put and output terminals would I e about 57 el l at 1000 c.p.s. with a fairly Aat gain fre 1uency characteristic I etween 300 to 10,000 c.p. s. :However, the repeater is designed ·o as to give a maximum gain at 1000 c.p. s. of about 35 db w hich is the value obtain d w hen the equ alizer is set to position 3. A pad of 3.8 el l is ad ded to th e P os. 2. ttin g of th ee 1ualize r and a pad of 21.5 lb for th e P os. 1 (Aat gain ) setting in ord er to maintain 35 db gain on all settings of the equalizer switch. This obviates hangin g the gain control potenti meter w hen chano·es in eq ua li zation arc mad e. P osition 2 w ill eq ualize al out 7.5 mil es and po ·i- . lion 3 al out 15 mi le of Briti h army fie ld quad cable. The eq ualizer cir cuits for each of th e three I ositions are shown in F ig. 10. T he gain control potentiometer is graduated in 10 equal steps and marked from 0 to 10. Gain frequency characteristics of the repeater for different position: of the eq uali zer and lo ·s frequency characteristics of th e cable are shown in F ig. 11. The repeater is capable of handling an output power of 100 milli watts or + 20 dbm with ab ut 3!f'o harmonics. A neon lamp with transform er (T-3) is provid ed to be used as a level indicator. T hi s in dicator may be connected across the output of either amplifi er by throwin g the "level" switch S4 to either A orB side, as shown in F ig . 8. The gain control is th en a lju ·ted until the lamp glows, w hi ch indicates an output of 6 to 8 dbm. The moni toring terminals A and B are conn ec ted through a swi tch marked TALK. to th e monitorin g windings and also to th e output ter min als of th e T2A and T2B coil s re pectively. This arrangement makes it possille to monitor and talk on the lin e in either direction from the monitoring terminals. 3.2 Power Unit The circuit fo r furnishing power for the ret eater is shown in Fig. 12. I t is arranged for operation either from the A. C. supply of 100-125 or 200-250 v or from a 12 volt battery. When the A. C. is used and con nec ted to the ·ocket marked A. . Main s, th e switch S6 should be thrown to the position marked "M I N " and the witch S7, which connects th e main s voltage to th e tran ·fo rm er T , adju. ted to the voltage of supply. This adjustment should always be made w ith sw itch S6 open in order lo prevent the possibility of extreme voltages at the hi gh voltage wind ing. The mains voltage is stepped up by the transform er T and the high voltage from terminal 10-11 rectifi ed by th e rectifi er, fi ltered and re sistances provid ed to give th e req uired D. C. voltages at the terminals. The heaters are supplied from a 12 volt w in ding 13-14 connected through one f the p les of 6 switch. W hen th e battery i used, the switch S6 is thrown to position marked BAT and the battery conn ected to terminals marked 12 v with polarity a· marked. Thi OJ erates the vibrator which, conn ected to a winding of th e transformer, generates th e hi gh voltage across terminals 10-11 which i rectifi ed an I fi ltered, as previously, giving the required D. C. voltage·. T he power for th e heaters i furnished di rectly fr m th e battery through a p le of th e S6 witch when thrown in the BAT direction. After everal thou and hours of servi ce, the rectif1er resistance goes up due to agin g which red uces the 130 and 110 volt A. C. plate battery voltages. At that time th e conn ection on terminal 11 of the power trans former may be remove I and conn ected to the hi gher potential terminal 12 to compensate for this change. 4. OPERATION 4.1 General A four wire circuit uses two pairs of wires, one pair for talking in 5 one direction and the other pair for the other direction. Repeaters are usually in stall ed at the terminals and between at regular intervals where ever possible. The gain s of the intermedia te repeaters make up for the loss of the lin e precedin g each one. In the case f the terminal repeaters, one sid e is conn ected through a hy brid coil arrangement o that trans mi ion can take place in either direction from the switchboard. The los fr eq uency characteristic of the lin e is compensated for by the eq ua lizer except in case of the amplifter of the terminal repeaters ·ending into the lin e, in which case the gain fr equency characteri stic is adjusted to be Aat I ecause the succeeding line is equalized in the next r epeater on the line. Fig. 7a shows schema ti call y a four-wire circuit eq uipped with repeaters. While the length of the cal le I etwcen repeaters may vary, this ar rangement shows 15 mil e of British fie ld quad cable, which i the maxi mum leng th of thi · type of cabl e that can be eq uali zed up to 10 K. C. with the avail able repeater gain. E quali zation is provid ed for 7y;; and 15 miles of this cable, the proper choice of which w ill give a satisfactory compromi se eq uali zation for any t-eq uired length up t 15 mil es. 4-2 Power Connection When the repeaters with power units are in stall ed a t the spacin g determined upon, they may be placed in operation by conn ectin g power from the mains or a 12 volt battery to the power uni t. If the mains are used, a power cable with plu g and socket connector, as hown in F ig . 13, is provided to connect between the main s outlet and to a plug mounted on the power unit marked A. C. MAIN . If the battery is used, it i conn ected to the terminals marked 12 V BAT. with the 1 olarity as in li cated. The current drain s for th ese methods of upplying power are a. foll ow· : Powe1' SuptJL')' Vo ltage Cu .n-e·nl A. C. (Lin e) 110 110 m iII iam peres A. C. (Line) 220 55 milliampere · Battery 12 1 ampere Office Battery 24 150 m iII i am peres Office Battery 130 20 milli amper es If th e repeater unit and power unit are tn the case, they have been connected by a cabl e, with sockets on each end, before mounting in the case, so that power will be suppli ed to the tube · by operatin g the power switch marked MAIN OFF BAT to MAIN or BAT, dependino· n the source of the power. I£ th e units are relay rack mounted, the con nections between th em ·hould be made by means of this s ket end e I cabl e before closing the power switch. Before cl osing the switch to the MAINS sid e, the switch marked M AI S VOLTAGE should be ad justed to a point within the range of th e supply voltage in ord er to pr - vent hi o- b voltages which would occur if the switch was on a low voltage poin t when hi g her supply voltages are used. A screwdriver or coin i · req uired fo r making this adjustment in ord er that once made there is less danger of it being accidentall y changed. (\ l If the repeater is located where it can be operated from the central office batteries, the spare ocket provided for that purpose should be wired, as shown in Fig. 12, and plu gged in to the receptacle on the re peater unit. W ith power conn ected to the repeater unit it shoul d operate satis factorily. I-:l.owever, if the means are avail able, it is desirable to make a gain test before connectin g it to the line. 4.3 Line Connections The switches marked 1 and 2 shou ld be operated to g ive the re quired impedance. For a terminal repeater, Sl should be set at 600 and S2 at 300 for the cable or to 1200 if the line impedance is approxim ately that valu e. For an in termediate repeater both Sl and S2 should be set at· 300 or 1200, w hichever more nearly approaches the line im pedance. The conn ection: between the cable and repeater at each point are shown in F ig. 13 for both the termin al and in termediate repeaters. The connections of the 1 airs f the quad to the repeaters may be determined by talking tests between ad jacent repeaters. T he pairs, identified as in co ming in either direction, shou ld be connected to the two terminals marked A IN and B IN between them and those id entifi ed as outgoin g hould be conn ected to terminals marked A OUT and B OUT between them. ln the case of a termin al repeater, the pair leadin g from the switch board should be conn ected to the termin als marked 2-W between them. 4.4 Circuit Operation W ith the. e connections made for each repeater the ·ircui t is ready for "lining up," which is done by ftrst settin o· the equalizer in either di rection to correspond to the known length of cable preceding the re peater except in the case of the sendin o· side of the terminal repeater w hi ch is always set on step 1 ( A. at gain ). T his being clo ne, the proper gain for each repeater may be determin ed by sending a milliwatt of 1000 c.p.s. tone from the two-wire side of first one and then the other terminal repeater and adjustin g the gain of the successive repeaters, with the LEVEL switch cl sed in the proper direction, until the neon lamp just glows, except that the gain of the receiving sid e of tf1e distant termin al repeater should be adjusted to give the required net loss as determined, wherever possil le, by mean of an overall transmission measurement. T he minimum net loss is determin ed by the balance of the terminatin g circuit again t 600 ohm:, a point below which the circuit would tend to sin g. 4.5 Monitoring and Talking In or ler to monitor in either direction a telephone set or monitorin g receive r ( not furnished with the repeater) shou lei be connected between either the terminal A orB and the middle termin al or between A and B for both directions. In order to talk on the line in either direction, a tele phone set shoul d be con nected to the termin als A and B and switch marked TALK thrown to A r B the direction req uired. See Fig. 14. 7 4.6 Signalling If it is required to signal wi th 20 c. p. s. on th e phantom, the terminals A I N and A OUT of th e pairs marked PH may be connected and also B I N and B OUT of th e same pairs, or for cross phantoming A I N is connected to B I N, and A OUT is connected t B OUT . The cross phantoming connecli ons are preferable because it breaks up a possibl e crosstalk coupling path around the two amplifi ers of the repeater. 5. PARTS LIST 5.1 Telephone Repeater TP-7 The T elephone Repeater TP-7 con ists of: Part No. N ame W 93-22 T elephone Repeater Unit W93-23 Power U nit W 93-21 O uter Case E quipped with Spares W 93-11 A. C. Main s Power Cable W 93-12 Current Supply Cabl e 5.2 W93-22 Telephone Repeater Unit Part *Ma1·/~ ing No . On Jte·m N ame W32-2 Panel W44-2 Chassis W33-1 Tube Cover P late W43-18 Tube Bracket W42-7 Dust Cover W43-9 Moun ting Bracket W28-3 Binding P o t Mounting Strip for Line onnec tions W28-S Binding Post Mounting Strip f r Monitoring T erminals W28-4 Binding Post Mounting trip for " P I-T." T erminals W43-ll I'"esist r Mounting Bracket for P art W30-ll Right Hand W 43-24 Resistor Mounting Bracket for P art W30-ll L eft H and W19-9 Plug (}or current supply) W17-1 Tube Socket W19-3 I anel Mounting Socket for Neon L amp W 93-8 Lamp Cap W20-7 Sl, S3 4 Pole- 2 Position Switch W20-8 S2 5 ·1 ole- 3 J osition Switch W93-10 ss T alkin g Key W93-9 S4 Level Indicator K ey W27- 1 Binding l osts ~ " H ead 8 Part *Ma,rking No. On Item Name W27-3 Binding Posts ~ " Head W26- l P ointer Knob W30-ll Resistor Mounting for 12 Resi tors W30-10 Re:istor Mounting for 4 Resislors W7-2 R13 Volume ontrol 250,000 Ohm W72-1 Ne n Lamp W72-5 VT 198A Vacuum Tube Type 6G6-G WS2-6 Volum e Control Grounding Clamp W49-8 P lu g Support W43-12 Cond enser Bracket W43-8 Resistor Mounting Bracket for l)arl \i\130-10 W15-6 T2 Output Transform er WlS-4 Tl Inpu t T ransformer W14-2 EQ Equali zer W15-3 T3 Level Indicator Transform er W3-10 C3 Co ndenser 2 Mfd. W3-10 C4 oncl enser 2 Mfd. WS-1 C7 Con lenser 0.01 Mfd. W3-ll C5 C6 C8 Cond enser Block 0. 5- 0. 5 - 0.5 Mfcl. W3-4 C9 Cond enser 0.0002 Mfcl. W 8-4 R5 Resistor 600 Ohm, ~ W alt W 8-4 R6 Resistor 600 Ohm, ~ Watt W 8-4 R14 Resistor 600 Ohm, ~ Watt W8-4 R22 Resistor 600 Ohm, 0 W att W 8- 10 R10 Resistor 510 Ohm, 0 W att W 8- l0 Rll Resistor 510 Ohm, 0 Watt W8-8 R12 Re ·istor 82 Ohm , ~ Watt W 8-14 RlS Resistor 11 ,300 Ohm, ~ W att W 8- 13 R1 6 Resistor 6200 Ohm, ~ W att W 8- 18 R19 Resistor 360,000 Ohm , 0 W alt W 8- 17 R l8 Resi: tor 43 ,000 Ohm, 0 W alt W 8-6 R1 Resistor 10 Ohm, 0 W att W 8-7 R2 Resistor 56 Ohm, 7~ Watt W 8-12 R3 Resistor 5 00 Ohm, ~ Watl W 8-16 R4 ] esistor 27,000 Ohm, ~ Watl W 8-15 R17 Resi ·tor 20,000 Ohm , 0 Watt W8-19 R21 h.esistor 4700 Ohm , 1 Watt W8-9 R8 Resistor 160 Ohm, 0 W att W 8-9 R9 Resistor 160 Ohm , 0 Watt W 8- l1 R7 Resistor 1000 Ohm , ~ W att W 8-2 R20 Resistor 430 Ohm, 0 W att W52-9 10-32 Stud WS0-4 Cable Clamp W43-13 Bracket for Volume Control 9 Part *Marking No. On Item Name W 59-21 Panel Bearing for )!,i. " Shaft 5.3 W93-23 Power Unit W32-3 Panel W44-l ·Chassis W42-5 Dust Cover W49-S Mounting F late WS0-5 Co llar W43-8 Resistor Mounting Bracket W49-6 Plu g Mounting pacer WlS-9 T Power Transform er W12-2 L4 Battery Filter Choke W12-1 L3 Filter Choke Assembly 22D0479 RECT-1 Rectifier W3-7 C17 Condenser Block W3-S CIS Co nd enser 0.05 Mfd 1000 D. . W. V. W3-22 C12 C13 Cl4 Condenser Block 0.001 - 0.001 - 0.001 Mfd. W3-6 ClO Co ndenser .05 Mfd. 400 D. C. W. V. W2-2 Cll Condenser E lectrolytic 1000 Mfds. WS-2 Cl 6 Co nd enser 0.1 Mfd. W2-3 Wafer for Mounting E lectrolytic Condenser W8-15 R26 Resistor 20,000 Ohm, 0 Watt W8-15 R27 Resistor 20,000 Ohm, 0 W att W8-21 R24 Resistor 51,000 Ohm , 1 Watt W8-20 R23 Resistor 47,000 Ohm , 1 Watt Wll-2 VIB-1 Vibrator- 12 Volt D. C. 100 c.p.s. W17-3 Socket for Vibrator- 4 Prong W20-6 S6 Switch-4] ole- Double Throw W20-S S7 Voltage Adjustin g Switch W19-7 Flush Type Plu g Wl9-9 Plug 8 Conductor W79-S Fuse 0.5 Ampere W79-4 Fuse 2.0 Ampere W17-6 Fuse Holder W28-6 Binding Post Mounting Strip W27-4 Rubber Covered Binding Post W 60-4 Vibrator Clip W30-10 H.esistor Mtg. for 4 Resistors W52-9 Stud #6-32 W52-17 Stud # 10-32 W43-10 Chassis Mounting Bracket W43-22 Cond enser Bracket 10 Part *Mar/ling No. On It em Name 5.4 W93-21 Outer Case Equipped with Spares W 93- 13 Outer Case W70-5 Strap W43-21 pare T ube and Vibrator Bracket W17-l Tube Socket W l 7-4 Vibrator Socket W72-5 VT198A Vacuum Tube 6G6-G W ll-2 V l B-1 V ibrator WS0-7 Spare P lu g Clamp W 19- ll Central Office Battery Cable ocket W 19-6 Extension Corel onn ector W 60-5 F use Cli p W79-5 F use 0.5 Ampere W79-4 F use 2 Ampere W63-9 Operation Label W 63-8 Schematic Label WS9- 14 Escutcheon ] in # 18 x :J.i " W 62-l Instruction Book 5.5 W93-ll A. C. Mains Power Cable Part No. Name W1 9-6 Connector Socket W19-8 A . . L in e Plug W 64-98 2 Co nductor F lexible Co r I W74-ll F ibre Washer 5.6 W93-12 Current Supply Cable Part No. Name W 65-3 6 Conductor Cabl e Wl9-10 Socket 8 Conductor W42-6 Socket Cover *A or B stamped on item after the par t nu mber designates hann el A or B. ll ::: ::5 12 "' 13 .-:::, I ' ._.__ .,_._.:...... -IICl-..·rlfk' S'rt .f'ift'tfitd# ,, ~_.., , .,. _, . 14 ,, .. I,. 'l 15 16 l i 18 19 ,...------~ 15 MILE CABLE ------, -- -- N C> -- -- TERMINAL REPEATER INTERMEDIATE INTERMEDIATE TERMINAL REPEATER REPEATER REPEATER HYBRID ARRANGEMENT FrG. 7a-Typica.l Four /!Vil·e Circu.it , ------.., I I I I AMPLIFIER A ! Hl~l~:r: I I I I 8 lA 4 W 300 IN ~~ A IPH [~ OUT l o- : 8 OUT PH I <>---:l. - I ,_:;; I --r- =r I Ll I B IN I I I L------J 4 WIRE 1200 OHM SETTINGS 2 WIRE 600 OHM AND 4 WIRE 300 OHM SETTINGS "" ------,------i r ' I ~ , , 1~14WI 300 OUT AMPLIFIER A 4 4w Ji~IE: 4W 300 IN """'II :J, 9~ ~~I~IL: AMPLIFIER B 80UT L ______3______J 4 WIRE 300 OHM SETTINGS LT. & R.M. FIG. 7b-Transfonner Co nuections at the Various l111p edance Switch Positious i 7 8 VARIABLE EQUALIZER SEE. N N 11300..... 6 12V +IIOV + 130V ~~~ Errata: .5 Mf. condenser in anode circuit of V lA connects to earth instead of cathode. I . T.&R.M. Frc. 8-Simplified Sche'llla tic Diu,gram of A m plifier TIA T2A 2 !Jrf ~~--=-~L~F::~--~-~ iE: I I I , ~o----..' · ~ I - AND --- I I 4 ' ~iltJ EQUALIZER : I ~ I ~ ~ ~ SEE FIG.8 I ~~ A~O~T J Z ------~c, ______j '"'= I 5•2 z S·l 5·2 pos. POS. I - 2W (;OOu...J I-4W 300.....- "Z.·4W 300~ 2-4W I"Z.OOu.J 3 -4 W 1'2.00u.l .N...., 3 0 0 Ill S-IN .4 ~ 2 Frc. 9-Coune-ctions fo·r Impedance Switch.es S-1 and S-2 POS.I POS. 2 7 8 10 ~00 ... ~~r 1 i( ···- ~~oo- -~ , •••~ o!...,.J I o "' 1[" l I - "' 9 ~lH'l LGr- r POS.3 ...."-' 10 POSITION I. FLAT GAIN POSITION 2 . EQUALIZATION FOR 7-1 MI. CABLE 2 * [ POSITION 3 . EQUAL! ZATION FOR 15 MI. CABLE* *BRIT. FIELD QUAD. CABLE NON LOADED I.T.&.R.M. FIG. 10-Circuits of Equali:::ation for Each Position of Switch ...... S-6 8 LEFT AC-RIGHT BAT. 0 .5 AMP 7 MAINS 0 +130 v 0 3 0 ~? ~ +IIOV I ~+IIOV u0 t- -t 1 I ~ 3 0\""' J 12 v 2 12V :L·-2--g- -4--s---6--7--~- 1 I SPARE SOCKET I L ------______J 2 4V 130V POWER CONNECTIONS WHEN - 1111+ - 1111111 + OFFICE BATTERI ES ARE USED ":'X-_CENTRAL OFFICE GROUND I. T. & R.M Frc. 12-Schematic of Powe-r Unit @0' CONNECTIONS FOR INTERMEDIATE REPEATER & LINE SIDE OF BRIT. FIELD QUAD TERMINAL REPEATER CABLE . PAIRS 1-3 . 2-4 ·~~· '"" 0 0 0 ~· :_~. ·o 1200·· D ·· · · ·· ·· ... ·· · ·· · ·· o ..... o.: .. • ~r- .. [ j [ j .::1200 •3. (Q·A A 100 6 S-1 0 0 0 S-2 A B [Q·B 0-~~·0 0-~- 0 "' " A . C MAINS ~: ; "~ ~ ... ~.. ,...... ~·~®00 0+ 12 V BAT. MA.INS VOLTAGE <@) MAINS OFF BAT. 0 - 0VIBRATOR "" ~ e= 0 MAINS BAT. !------6 ..-T. $O<;KtT FOR A .C . MAINS ~UC. ~~ ONPANEL I ~ ~ A. C . LINt: PLUG POWER CABLE I. T .& R-oM . FrG. 13-Panels for Repeater Showing Cable Co 11 11ec tions I' ....__/ "' t ' ,.... I TIA T2A ® 4-W ~ ~----:::MP~F~; A-- I_ :=~~;..+.--~~=:!~ I I AND I t I '-- 3 A-IN 4 To sw. ~~ 13 1 . 1 --- r <>-i ______;,_AJ SEE FIG. 9 --- ,.f-, ,. f-o, r-1 ~ r-l • 1 1 1 1 1 wP~rJFt 1 .1 ® ~® :MON·B MON-A FIG. 14--Connectio11s for Talking mrd Monitoring Errata: C6A and C6B condensers should re turn to earth i. e. terminal 3 on the condenser block connects to earth and terminal 5 to cathode. In Fig. B-R2B should be R21B. FIG. A SPARE PARTS IN COVER 2· 6GV-G VACUUM TUBE5 1-WII-2 VlaRATOR. 4-W 1- 2~·130 V. BATTERY PLUG I - SPARE LINE C.O)oo.INECTOR F'LUG A·OUT I· 2 A•.•t:> F'U~E 1 - -5 ~ t "'P F USE VACUUM TUBE DATA C..Ol.II'L C.OOE 5G C.OOE VIA ~~ !0- NOTE~ T INDICATES CONNECTIONS TO CHAS515 I - L I A , L2A, C lA & C2A ARE A~5EMBLED IN A CASE WITH TERMINAl.$ A!. SHOWN; SI MILAFU.. Y L1 6 , L2B ,C.IB,& C26. PO~ t -4w~- PH 2- COILS MARKED •nA ARE A~SEMBLED IN 2-4W 1'200- ONE CASE;SIMIL ARLY F"OR •TIS" COILS. 3· CONOEHSESZ C5A,CG-A& C&A ARE IN 5AME C. AN WITH TERMINALS AS SoHOWN. 51 MIL ARLV <:.58, CCOB I. c.ee. till 1'1 '('N \0"' . II FIG.B POWER CONNECTIONS WHEN OFFICE B.ATTERJE~ AQE USED V2A VIA VI B V2 B «kd~~~~~~ii ~ ~ ~~,;:'r 3 4 ' 16 7 oa ~I I I I ~ ~ol I I I I I I I 1 I 1+130 V -----'---l--_j I I+ nov AC I I ,.... I +IIOV I i I I I I ~-=- OFFIC.t. GR0Uh0 I .- I 1 l ,z v I SCHEMATIC I I /. T.& T. 103-A TELEPHONE REPEATER SIGNAL CORPS U.S.ARMY i- I L __ _j TELEPHONE REPEATER TP · 7 lnferuotional Tefeplrotte & R~dio ltlf_g. Corp. FIG. 15 .... NOTES - NOTES