Section II. INTERCOMMUNICATION CIRCUITS DETAILED THEORY

TM 32-5895-227-14&P

Section II. INTERCOMMUNICATION CIRCUITS DETAILED THEORY

with a handset through the audio volume compression

6-5 GENERAL. The basic ICOM circuits are shown in

circuit AMP 2, AMP 3, AMP 4 at the telephone set is

figures 6-2 through 6-9 and in FO-2 through FO-4. The

established with the RICS headset and microphone

visual call indicator is energized by the blinker circuit.

through AMP 1, AMP 2, and AMP 3.

Typical position circuits are outstation to RICS, CCC to

c. Transfer operation by Trick Chief must be

RICS, CCC to outstation, and special intercom. The

initiated at SB-2601/G.

Station selection is

signal level of communication is controlled by an audio

accomplished with relay switching directly connected to

volume compression circuit.

J2 of SB-2601/G. Relays K1 through K18, which are

mounted in the OA-7735/G panel control station,

6-6 BLINKER CIRCUIT . See figure 6-2. The flasher

provide

selection

for

interconnecting

the

circuit with ISCRI and ISCR2 form a basic D-C flip-flop.

intercommunication channel.

The lamp load at pin E of the terminal blocks is

d. The position indicator light at J1 of the RICS is

connected in the cathode leg of ISCR2 so that one side

controlled by SB-2601/G.

of the load may be at ground (negative) potential. Flip-

flop timing is controlled by a conventional UJT oscillator

6-8

ICOM CIRCUIT, CCC TO RICS. See FO-3.

arrangement QI (2N2646) 1RS, IC1. Diode 1CRI and

a. A call may be originated from either position,

resistor 1R2 give required on/off timing independence

and symmetry adjustment. Resistor 1R5 determines the

as illustrated in the sample circuit shown in FO-3.

period adjustment for the flasher circuit. Tank circuit of

Intercommunication is initiated from the ICOM position

1R8, 1C3, 1C4, and 1R9 energize a maximum of 18

of OA7735/G to SB-2602/G by pushing switch SI and

simultaneous flashing positions.

energizing relays that are shown. Blinker flasher circuit

a. The most important feature of the injunction

B1 and B2 is energized in both positions as a call

function, with green indicators visibly blinking. Wiring

transistor 2N2646 is its highly stable negative resistance

from the CCC position to J18 is point-to-point. Relay

characteristic, which permits its application in the blinker

switching at OA7735/G couples J18 through cable

circuit.

assembly CX-1104/U to ICOM position SB-2602/G

b. Blinker circuits are located in Communication

switchboard J7. Cable Assembly CX-1104/U is pin-to-

Control Console (CCC) OA-7735/G and Radio Intercept

pin wiring. The circuit is completed at J7 of SB-2602/G.

Control Switchboard (RICS) SB-2602/G.

Visual

The answer function is completed at SB-2602/G by

Indicator ICOM blinking signals on the Telephone Sets

pushing the intercom switch. The blinking circuit is

TA-676/G and Monitor Control Panel SB-2600/G are

deactivated and a steady-state green light indication is

powered from the CCC or RICS units.

obtained.

b. ICOM communication with a headset and a

6-7 ICOM CIRCUIT OUTSTATION TO RICS . See

mike through the audio volume compression circuit

FO-2. A call may be originated from either position, as

AMP 1 and AMP 2 at CCC is established with the RICS

the

sample

circuit

FO-2

illustrates.

headset and mike through AMP 2 and AMP 3.

Intercommunication is initiated from the ICOM position

of the SB-2602/G to an Outstation position TA-676/G by

6-9 ICOM CIRCUIT, CCC TO OUTSTATION . See

pushing SWI and energizing KI. The blinker flashing

FO-4.

circuit is energized in both positions as a call function,

a. Origination of a call can be made by either

with green indicators visibly blinking.

a. Wiring from RICS position Channel I to

position as shown in the sample circuit in FO-4.

Intercommunication is established from the ICOM

communications control console (CCC) J21, is point-to-

position of OA-7735/G to an outstanding position SB-

point. Relay switching at the CCC couples J18 to pin-to-

2600/G by pushing the ICOM switch and energizing the

pin connections at Connector Assembly MX-7141/M.

relays that are shown. The blinker flashing circuit is

External interconnecting cables complete the circuit

energized in both positions as a call function, with green

between MX-7141/M in the AN/MSQ-71 central station

indicators visibly flashing. Wiring from CCC position J1

and outstation position MX-7142/G or MX-7143/G. See

to outstation position SB-2600/G J5 is point-to-point.

figures 3-6, 6-3, 6-4, 6-5, and 6-6 for connector

Relay switching at OA-7735/G couples J1, pin-to-pin

assembly wiring.

connections, as Connector Assembly MS 7141/M.

b. The circuit is completed at J2 of TA676/G

External connecting cables complete the circuit between

outstation position. The answer function is completed at

MX 7141 /M in the AN/MSQ-71 central station and the

TA676/G by pushing S2 and energizing 2K1 and 2K2.

outstation position MX 7143/G. See figures 6-3, 6-4, 6-

The biking circuit is de-activated and a steady-state

5, and 6-6 for connector assembly detailed wiring.

green light indication is obtained. ICOM communication

6-3