l

I

l l

EIB(MD) 01·~

EID RINGER

54-TYPE CONTROl_ UI'-/IT (LOCeHE NEAR MONITOR STATION)

760A LOUDSPEAKER

WITH 69A BRACI<ET

INDOOR REMOTE STATIONS

?EO A LOUDS~'Et1KER

1. GENERAL

CO AND INTERPHONE LiNt:S

1.01 This section is reissued to:

• Include schematic diagrams of control unit formerly found in Section 512-515-400.

• Include information on 54B control unit and ElD ringer.

• Show that the 54A control unit and ElB ringer are rated MD.

Since this reissue covers a general rev1s10n, ar­rows ordinarily used to indicate changes have been omitted.

CENTRAL OFFICE LINE

rNTERPHOr~E LINE ONLY

(a) Planning

MONITOR STATION

KS-16846,LI l.OUDSPEAKER

OUTDOOR REMOTE LOUDSPEAKER

(1) When planning the 2A farm interphone installation, consider the following:

• Avoid placing apparatus with plastic covers or parts in locations where the ambient temperature may exceed 140 degrees F.

• Any combination up to a total of six loudspeakers may be used, provided, no more than three are outdoor speakers

")A:n·-i·c2._n Teiephone c.;_:·;d Tdegrapb Printed in U.S.A.

the out door

0 telephone set 2~Jine

up and signaling and sufficient mounting cord conductors rnay be used with the farm lnterphonc sys­tem.

• Loudspeakers at all stations (except outdoor type) should be located as near the associated telephone set as prac­ticable for customer to obtain maximum benefit from telephone usage as well as loudspeakers.

• 759-type loudspeakers should be located so that volume control is readily access­able.

• Control unit should be located near monitor station for ease of wiring.

• Control unit should be located within 6 feet (length of power cord) of a nov, 60Hz ac power receptacle which is not under control of a switch.

• The monitor station is the major loca­tion in the system and should be located in an area usually occupied during the time of day that the customer has the greatest need for the monitor feature.

ft . . A 0

The of monitm· station lacks secrecy. If any stat-ion is up and handset button is not op­erated, it is possible to listen to activities in the monitor station area. This condi­tion has advantages and disadvantages which should be explained to the cus­tomer. A cutoff key may be necessary.

• The KS-16846, List 1 loudspeaker (out­door type) effectively covers an area that extends 60 degrees on each side of the center line of the speaker and so should be oriented toward the area where coverage is desired.

~Outdoor loudspeakers commonly are ~ placed in areas where exposure to light·

Use cords, station nt-side

poncnts of the in.tcreonnect coin-

from_ the weatheL _For con1JJ01l

to weather, use exterior vvn'lng shnilar to drop wire. On longer runs of wiring, the loop resistance must be considered. Table A shows the maximum length of various wires used to interconnect stations of the system. These distances plus the central office loop must not exceed the working limits of the central office.

TABlE A

SEPARATIONS Of STATIONS

MAXIMUM LENGTH TYPE CONDUCTOR !N FEU*

Drop Wire 6,000 Multiple Drop Wire 4,000 B Rural Wire 16,000 D Station Wire 19,000 Inside Wire Cable 5,000 109 Line Wire 16,000

* This length plus central office loop must not exceed working lim.its of central office.

(b)

@ Use eare in unpacking .~v'H"m components to prevent dmnage to plastic covers and controls.

(c) Installing

(1) 54-type Control Units

® Loosen two captive screws and rernove cover. Remove P-15E917 plastic caps from cable entrance openings of cover.

• Mount in upright position (as marked on chassis) to a flat surface. Avoid lo­cations which may be snb.iect to dust, temperature or humidity extremes, or abuse.

ticms, iTse SCXCV,f

a11 terminations,

i/dal'ce ruJ> trol unii'"

e Replace cover) then close off unused por­tion of cable entrance openings by break­ing plastic caps on indented marks with long-nose pliers and snapping into posi­tion.

• Plug power cord into suitable ac re­ceptacle.

(2) 759B Loudspeaker

e Loosen two captive screws and remove cover.

• Mount vertically or horizontally with volume control oriented as to be readily accessible. Install as near as practicable to associated telephone set.

• Can be secured by four screws through base. Base is also drilled to permit mounting on a 63A bracket or to a stand­ard electrical outlet box by using- a 146B adapter.

., Make connections as shcn,vn in appropri­ate connections and maintenance sec~

tion. Cord and cable entrance is through holes provided in base or knockouts at end of base.

• The 12-terminal connecting block serves as a bridg-ing- point between control unit, loudspeaker, and telephone set. Use screw-type terminals for all ten11ina­tions.

• Replace cover.

(3) 760A Loudspeaker

• Either place on flat surface such as table, shelf, or counter top or install on wall using 139A bracket.

• To use 69A bracket, secure bracket to wall, insert loudspeaker cord through

vided,

c.o:;;rr.eetlo:ns to sarn.c block as the associated teit·-

phone set cord. If is a wail-type cord inside set.

KS-16846, List 1 Loudspeaker

• Install by securing swivel base to flat surface with suitable fasteners or by re­moving- circular base of swivel mount­ing and attaching speaker to 1/2-inch pipe.

• Orient horn to area where coverage is required.

• Make connections to suitable connecting block in weatherproof housing.

Review station protection procedures. Use station protectors on all circuits ex· posed to lightning.

(5) ElB (MD) or ElD Ringer

• Install at monitor station only.

*' Ren1ove housing and securE; base to flat surface '.vith suitable fasteners. Four gron11Y1eted 1nounting holes are provided in the base. Orient volume control slide to provide ready access to user.

e Make connecticns as shown in Fig. 2 or appropriate telephone set connection and maintenance section. Replace cover.

• As connected, ring-er provides ringing at monitor station and tone ringing sig-nal at all other loudspeaker stations throug-h relay in control unit. If tone ringing- is desired at monitor station, strap terminal Jl to terminal J2 at con­trol unit terminal board.

• The volume control of the ElB (MD) or ElD ringer controls both ring-er and tone ringing- to remote stations. When placed in the hig-h volume position, the tone ringing feature is disabled and only

lVote: When is eo:nneeted 1

used in the ;nto'>''h'"'" be disconnected. JYionitor station ringer should present the only ringing bridge to the central office line. Ring signal to other stations will be provided by tone ringing relay in control unit.

(6) Service Options

Auxiliary monitor station

• If an auxiliary monitor station is de­sired it can be wired in parallel to the main monitor station and bridged at the control unit or the 759A loud­speaker.

• The SA lead of the control unit can be extended to one monitor location only. This lead is used to shunt the volume control of the monitor loudspeaker and permits any remote station to transmit using their handset and be received at full volume at the shunted loudspeaker.

Cutoff key

• If privacy is desired at monitor station install a cutoff key (6017-type key or equivalent) near the monitor station telephone set. Wire the key between terminal 7 of the 759A loudspeaker and terminal C of the control unit.

• When the cutoff key is opened, remote stations can not go off-hook and listen to sounds or activities in the area of the monitor station.

Transmitter amplifier

• In long loop conditions which require amplification of the G-type handset transmitter, two amplifiers (276A and 277 A) are available for installation in the handset.

"'i11· j j'l.(•

;;, ;gA is used cnn c:nts of the is the sarrw 'lS a '2/Tfiis,_ ,,z,::erJt a

is included to nrnt,•d ""'"n<e11ine reversal.

'I'he arnplifier is installed inside the G!SKH handset transn:litter cavity with the handset cord transmitter leads con-· nected to terminals L and V so that the V terminal is positive with respect to L. The transmitter unit is then installed and the cap replaced.

~ !malate the handset cord stay band ~ with electrician's tape to prevent pos­

sible shorting of amplifier components.

• See Section 501-226-100 for complete de­scriptive information and schematic.s of transmitter amplifiers.

Auxiliary DC voltage

• -35 volts de voltage is available at the control unit terminal marked DC for uses external to the control unit.

• Connections to this terminal should be made by leads external to the system wiring and the following caution strictly followed.

CAUTION: Wherever possible, leads con, nected to the IJC terminal should m;t be exposed. however, are exposed~ the control unit must be protected fmm lightning or power surges applied to the connecting cables. A KS-19150L1 (72-ohm, 1/2 watt) resistor, in addition to normal protection, must be connected between the protector blocks and the IJC terminal.

• There are normally no requirements for power from the DC terminal within the 2A farm interphone system.

3. MAINTENANCE

ft Remove power from 54-type control unit before attempting any maintenance of interplwne components.

* Do not use cc''"''ino' DOwdel''S or c.leansers on colored apparatus,

Do not al.low excess water to enter grills of loudspeaker mtits.

• If cleaning does not produce the desired effect, replace the component.

(b) Inspecting

• Housings or covers should not be warped or discolored.

• Turnbuttons and volume controls should work freely without binding or sticking.

@ Wiring and mounting cords should be checked for damage to the insulating covering and should not be placed to pre­sent a hazard to cnstomer or equipment.

• Screen behind louvers of control unit cover should be intact and free of obstructions.

(c) Troubleshooting

• Table B provides a list of the more com­mon troubles encountered with 2A farm interphone and their probable causes with recommended corrective action.

(d) Connection Index

Fig. 2- Line and Ringer Connections

Fig. 3- 54A (MD) Control Unit, Sche­matic Showing Modification Us­ing D-180117 Kit of Parts

Fig. 4- 54B Control Unit, Schematic

(e) Replaceable Apparatus

(1) 54-Type Control Unit

• KS-16935, List 11 Cord (power)

• P-15E918 Cover Assembly

• RM-784064 Fuse (3/4-amp.)

nance 1s any cornpo·-test ec:tch station in for

proper operation of central office line pkktJp and hold as well as the interphone features.

fit ~ E A D

lY!ake rw adinsiFnents on. the "'k·ClJrpe con@ trol unit.

(2) Test monitor station output with one or more remote stations being received at

full volume. Using volume control, lower the output of the monitor loudspeaker. If factory furnished volume control (100 ohm potentiometer) does not lower audio output sufficiently, a 1000-ohm P-25E020 potentiom· eter may be substituted. Assure tbat volume cannot be cut off completely.

Note: Customer should be forewarned that hands-free operation at the monitor station will be affected by the increase in volume control resistance and that it will be neces­sary to increase volume when transmitting for satisfactory results.

(3) In cases of :radio frequency interference, proceed as foliows:

a. If a series one amplifier is used (marked P-12E487 SER 1 or P-20F193

SER 1), place a KS-13814, List 1 capacitor (0.05 f"f) between terminals 3 and 4 of the 2563C transformer in the control unit.

b. If interference is still encountered, pro­ceed as follows:

• If interference is heard in the handset when it is used for monitoring, with neither push-to-talk bar depressed nor the quieting relay actuated, connect an additional KS-13814, List 1 (0.05 f"f) capacitor between terminals C and Sl of the control unit terminal strip.

l'<~ge 6

;,rul"lc heard on ti1c set \Vhen the handset is off h.ook a:nd

""" vu tors in. series rnay )yc; usecL

paeitor between terminals 2R an_d 2T of the control. unit terminal

'* Hefer to sections in the Divi-

0 If radio frequency interference is heard on the handset after the quieting relay has been actuated, connect a KS-13814, List 4 or 542L (0.1 JLf) capacitor be-

sion 502 for nudntenance of the various telephone sets associated with the :fa:r:m interphone syst0m.

• Replace G5KR handset if push-to-talk switch does not function properly.

2A FARM INTERPHONE COMMON TROUBLES AND PROBABLE CAUSE

TROUBlE PROBABLE CAUSE CORRIECT!ON

Incorrect or defective Rearrange, repair, o:r Individual speaker not wiring replace wiring

operating properly .

Defective speaker Replace speaker

Incorrect or defective wiring to Rearrange, repair or Weak or noisy output one or 1nore speaker locations replace wiring

on all speakers Defective control unit Replace control unit

Crosstalk between Split cable pairs Rearrange wiring CO line and

. .. """~-"·-

Output of control unit Replace control unit intercom line too high

I AC power supply off or Check AC nower or

1-- plug pulled out place plug back in outlet System completely ~·~"

dead Blown. fuse Replace fuse (3/4 amp) ~-----·- -------- - ·-

Defective control nnit Replace control unit

.... ....... 1':18 (MD) oe EIO :<INGER

p 8 ;

9 l STRAP

5 I ( l'lOTE I)

§ l

RINGER CONNECTIONS

E!B (MOl OR 6878 EID RINGER SUB SET

(NOTE 2) p

a I 0--9 Ll

6 i 2

f p L2

5 8,( 8 G \ ~

(NOTE

' S4~·TYI~r::

CO;HI'OL Ui•J IT

r;: c

~

i IR

,_ GO ' -

p

j

J

l l

3

TIP

RING c.o. LINE {TABLE C)

i-- ---- _!!_R~

54-TYPE CONTROL UNIT

RG

c

;:: IR

GO J c.o. LINE (TABLE C)

CONNECTIONS FOR POLARIZED RINGING USING 6878 SUBSCRIBER SET

TABLE C C 0 LINE CONNECTIONS

CLASS OF SERVICE RING

INDIVIDUAL; BRIDGED IR

RING PARTY IR

TIP PARTY IT

ALL POS AND NEG RING PARTIES IR

ALL POS ANO NEG TIP PARTIES IT

* NOT REQUIRED, SEE NOTE I

TIP GRD

IT * IT GO

IR GO

IT GD

IR GO

NOTES:

FOR INDIVIDUAL OR BRIDGED SERVICE PLACE STRAP AS SHOWN. DO NOT CONNECT PROTECTOR GROUND AT CONTROL UNIT.

2. MODIFY 6878 SUBSCRIBER SET AS FOLLOWS:

FOR All POSITIVE PARTIES MOVE (BR-BL} LEAD

FROM TERMINAL I TO TERMINAL L2.

FOR ALL NEGATIVE PARTIES MOVE {BR~BL) LEAD FROM TERMINAL I TO TERMINAL G.

3. CONNECTIONS SHOWN FOR NEGATIVE PARTIES. FOR POSITIVE PARTIES CONNECT IR TO G AND GO TO L2.

8 INDICATES CONNECTION FOR NEGATIVE PARTIES.

(±) INDICATES CONNECTION FOR POSITIVE PARTIES.

fig. 2- line and Ringer Connections

I0 T 21~ RG

0

C46 10

40_1+34

~~~ 39 510

R44 38 IlK 32

L

0.25 IC47 35 '

29

\ OPARTOFJ ~ -20F584

41 23 . PRINTED

C4S Rl NG BOARD

42 °·25 24 ! ~~ I

I " ! ! R42 R3

45 220 27 30 (NOTE 2)

C43 CR71

100 400J

.-!'c;:f 28

I R41 470 37

31 CR41 400J

30 I 2 36

f-o-::_=== s

3 T2 4 2563C TRANS

AK-IO~~~ tU __ -~9_l_B~2_JMI2 QUIETING Ill -~ i: I

RELAY .. 9 lrr _________ -J--J---j--f---)

BATTERY FEED RELAY

t---+---KC:2~AJ n-57 (B) MG

c

"" [_ : ---'

L 2

I

2Uj IU ~4 _ _::~4~8- M~O ~6-:'f L2U ILl-, Ts r;o Ts 1~2 ~~

I

K

TO s HEET 2

Fig. 3- 54A (MD) Control Unil, Schematic Showing Moc!iflcaiioo Using D-180117 Kil of P<irls !Sheel I of 21

-- 35 v -35V

'"' A ____ .._l'o:'_<'KI~-05-V---;AAIN M;~iFiER WIFKJ::;;-1~-'--~-P-~i':E'~!'-'--~~~~-.-------~---:~, -':',2 3::: ' (N~:JDII I ' I 1 "v eRN I >T---1---1---+-hl~ ' ~-

1 3oK 420t< ~ 1 E r ~ Rs2

"---"-_j:-(F -, ~ ~~ 66647 ~:' : I : ! 5 A 4.87 8

I l'n-~~--~--~LO~--~ I RIB L Cl9 ..........., I I i (NOT~ I)~ I I lOOK '~' 0.00022 (!-"" 013 I J CR3 I I ~ ....... ) I I 1«\0II :::l:::: g~~l \k IS-A I I CR4 I 05~ I R24 ') 12G -::_~_..., Cl2 .----) -...__:; I I I 200K + I «i -Q 12 I B >-'-,---1--1----l----1--+-<7> 2 I i "L R20 R21

12H -~g~~047 Rl4j I RSI I

I ~ IK 470 - :-.t+ IK I I 4.87

' Rl4 '" T ; 11, ' 1 A >-r-l-,-t-l

1r-4---++c1e-'I/W---oA

I SIK 270 I 100 Rl2 I I I I Rll 470 I I I I 20K Cl4 Lll 'c:"CI5 I I

II"-'--41< -~+--1--~0.0I 1535A IND ...:_ 0.01 I ' I f----- I 7 H >-'--

D

AUDIO INPUT I

I

1 I [..,CIS 0.022

Rl7 20K

1 I Cl3 RIS

E I I 0 1~5 1.5 MEG

OSCILATOR N 1(1--\---------___:WV~---J

+35V

I

P-20F564 PRINTED WIRING BOARD

(PART OF D-180117

KIT OF PARTS)

TRA~;~STOR ! (P-12E475) I

'I~~ TO MODULATING

SIGNAL __ i SHEET I

F INPUT JBi

L

C48 500

+I' I M

K

Rl 10

RV3

RV2

RVI

--+-~~ __ J_ ______ ~ P-12E490 POWER SUPPLY PANEL I 35V ,------------

115 v

~~,~~~~~~ 15 17 ~~!:~~ I '_;~"-~-o'-6o-+;>--,-,-11~~~ 1pl[[--~~;; ~"1ooo c 16 ;(d426A 12 ~-;~ II

Fl 3/4 AMP

-35V

NOTES:

I. 051 AND 052 ARE A MATCHED PAIR OF GERMANIUM P-N-P ALLOY JUNCTION TRANSISTORS. THIS MATCHED PAIR IS CODED I<S-16843, LIST!. BOTH MUST BE REPLACED IF EITHER FAILS.

2. COMPONENTS AND LEADS DRAWN WITH HEAVY LINES INDICATE MODIFICATION USING D-160117 KIT OF PARTS

3. REMOVED WHEN MODIF:JED AND CONNECTED THROUGH Rl

Fig. 3-54.1!. (MDJ Control Unit, Schematic Showing Modificalion Using !l-180Jl7 Kit ol Paris IShee! 2 of 21

~- ----------"-"""~-------

1 PT 2R RG

TERt.WJAI_ PLATE /.\SSEiiBLY

52 S3

~~2 ~ --~

0 ~ $ R61

100 J2

r -~

I I

I I

- C4s--~

10 40 - + 34

L R43 39 510

R44 38 IlK 32

Jr 35 ,:s "

41~r~,, C45 R46

~~5 68 24

42fl1R47 30 47

R42 45 220 27

K3 AG-33 (R)

RING RELAY

lor IL

I

I I

2 CR71

"': tu~ M9 AK 10 (A)

QUIETING IU :;._-RELAY 9

BATTERY FEED RELAY

K2 A5 57(8)

I 2

>--L----3 T2 4

2U! niU M4 88 MS MIO 86 t-2Lu /" ~ --Ts1~--cr~l

21 ' 48 I ---¥A~4-~---------+----4--------------,

R46 I 10

30 CR41 136 I 2

R45 21 261 22

C42

25 2 43

I

PUSH TO TALl< I 2

83~-~~3- 8 4 _;i. RELAY IL ":'':<: _:+_--KIA - _:'>i--

AK-10 2L PT 81 Ml 82 M2 4 M4 M5

R71 APPARATUS BOARD 2.15

ASSEMBLY

~~

fig. 4- 54!1 Control Unll, Schematic (Sheel 1 of 2)

Sl SW

0$ 9

L~ D

E

T 0 SHEET 2

F

I ! !

! G -----I

II

I

J

!

'

TO SHEET I

I

I - s" ,-~--~ -~ ~~ ~~----~- - ~ --~--~- -~ ~- -~-~--- ~-"

M,IPLIFiER PRINTED WIRING BOARD

l J2J ' I I I

I I I I

Ia I ,: :

I

RIB 2; !_, Gl9 lOOK 0.00022

R24

8>0 30K

C20 --ti_ 0.001 ~

013

R23 IK

I I I I I

I I I I

I

I 200K

2 ;L -

«)o" '"" "2 + I

I R20

IK

t---,="+---'~~-1) 012 t-,-16 _ __,__-1-------lb R21 0.0047 ~~3 270 -\t+

Rl4 RIG 51 X 270

"4 I I I RH

20K c o~;1

I '-----r< L I 'I " l

I I I ~CIS Rl7 20K

LH

'" 100 Rl2 470

015 0.01

OSCILATOR I (J I ~~---<~~---4-------~$ 0 ~~~~i: ~~ 1 toozz

E S~G%~ULLfJi~* I R ~ 0~~~ ~ -~-----1.5-R-~S_EG_ --~----y C48

-35V

I I 'T l~~~ I I os2 I

)-!-~~~·-'--(;) R52

4.87

~r----+01---;' N~lTE£)

11 o~ I >4-+--t-02 I

R51 4.87

I A

I I I TRANSISTOR i

BOX ASSEMBLY

F AUDIO OUTPUT J21 5~0 +kr---------------------------------~

G

H

I

Jl

: ! I

k PREAMPLIFIER PRINTED WIRING BOARD

J

'\~ •OI!AE81 R4 Rl 12G " R3 -;;;-;:::=====+----~ a>~J

I I I IOK IK 5100 loK E I

> ~ Cl 'f-<>-IM---4H-4A'r------p A >-11---+-----~

I :L_~f'_~i + 40 ll It-I "

I I I

~-----+---4----------~»i: 0~ F

C - OUTPUT

+J._ C31 + ::::: C32 -""" 1000 .:: ...... 1000

NOTEs:

PI Tl ~--- ~ -+--+- - -----h

~II I 17 I I CR31

ts 13 I P"'--+--+--<)14 II 116 CR32 R33 Fl

R32

47K -35V I I ~s'<-1 __ _.:l_o2<>-,_,'v·l6r--4-----4----+ I

I Q51 AND 052 ARE A MATCHED PAIR OF GERMANIUM P-N-P ALLOY JUNCTION TRANSISTORS. THIS MATCHED PAIR IS CODED KS-16843, li. BOTH MUST BE REPLACED IF EITHER FAILS.

L_il TERMINAL BOARD ASSEMBLY

fig. 4- 5411 Control Unil, Schematic (Sheel 2 ol 21

!1 ll Pages