Signal Path of TS-1967/ARC-54 Connected to Receiver-Transmitter, Radio RT-348/ARC-54

TM 11-6625-601-34

simulated over-target homing signal is routed

include unit and functional megahertz selec-

from the homing circuit, through pin NN of jack

tion, odd- and even-megahertz ground control,

J101 and pin NN of jack J16, to the horizontal

and harmonic filter operation. Setting the fre-

needle circuit in the ID-48/ARN. Ground for the

quency selector on the test set to a specific fre-

simulated over-target homing signal is applied,

quency codes the unit and fractional megahertz

through contacts 5 and 8 of switch S3A (front),

control wires. This coded information is applied

pin 21 of plug P4, and contacts 2 and 5 of switch

to the tuning circuit in the RT-348/ARC-54. The

S10C (rear), to the horizontal needle circuit in

tuning circuit selects the operating frequency

the ID-48/ARN; this causes the horizontal nee-

of the RT348/ARC-54 corresponding to the

dle to swing down. Operating voltage of +27.5

coded information. The unit megahertz control

volts dc for the ID-48/ARN flags is obtained

wires, designated A through E, are connected,

from the C-3835/ARC-54. The voltage is applied

TEST FUNCTION SELECTOR

through

from the C-3835/ARC-54, through pin GG of jack

switches S11 and S1., RCVR/XMTR jack J11,

J101, pin GG of jack J16, and contacts 3 and 4

and plug P1005 of the RT-348/ARC-54, to the

of switch S11C (rear), to the flag circuit in the

tuning circuit. The fractional megahertz control

ID-48/ARN. Control ground for the flags is

wires, designated A through E, are connected,

obtained from retransmit ground switch S1.

through switches S11 and S10, jack J11, and

Setting switch S1 to RETRANS TONE or

plug P1005 of the RT-348/ARC-54, to the tuning

RETRANS CARR applies ground to pin 11 or

circuit. Selecting an odd-megahertz frequency

10, respectively, of plug P4. From pin 11 or 10,

applies ground from the frequency selector in

ground is applied through contacts 11 and 2 of

the test set, through contacts 8 and 10 of switch

switch S10F (front) or contacts 8 and 11 of

S11E (front), contacts 11 and 9 of switch S10C

switch S10D (rear), respectively, to pin Y or Z

(rear), pin 32 of jack J11, and pin 32 of plug

of jack J16. The retransmit carrier ground or

the

tuning

circuit

P1005, to

the

retransmit tone ground applied to pin Y or Z,

RT-348/ARC-54. Selecting an even-megahertz

respectively, of jack J16 is routed through pin

frequency applies ground from the frequency

selector in the test set, through contacts 2 and

Y or Z of jack J101 to the retransmit control

circuit in the C-3835/ARC-54. From the retran-

4 of switch S11B (rear), contacts 11 and 9 of

s m i t control circuit in the C-3835/ARC-54,

switch S10E (rear), pin 37 of jack J11, and pin

ground is routed, through pin FF of jack J101,

37 of plug P1005, to the tuning circuit in the

pin FF of jack J16 on the test set, and contacts

RT-348/ARC-54. When any frequency below 46

3 and 4 of switch S11F (front), to the flag circuit

megahertz is selected and transmit control

in the ID-48/ARN, which activates the flags.

switch S6 is set to PTT or XMIT, ground is

The homer operate voltage obtained from the

applied from S6 through the harmonic filter con-

homer circuit in the C-3835/ARC-54 is applied,

trol to contact 8 of switch S11B (rear). Ground

through pin DD of jack J101, pin DD of jack J16

is routed, through contacts 8 and 10 of switch

on the test set, and contacts 9 and 10 of switch

S11B (rear), pin 4 of jack J11, and pin 4 of plug

S 1 1 C (rear), to HOME lamp DS8 in the

P1005, to the harmonic filter circuit in the

simulator, which causes the lamp to light.

RT-348/ARC-54. Transmit control switch S6 is

normally in the RCV position as shown on figure

1-8. Signal Path of TS-1967/ARC-54 Con-

FO-5. When the switch is set to XMIT, contacts

nected to Receiver-Transmitter, Radio

3 and 5 open, and 6 and 7 close. Contacts 2 and

RT-348/ARC-54

8, and 1 and 4 remain as shown. When the switch

(Fig. FO-5)

is set to PTT, contacts 2 and 8 are closed, and

The operating functions of the RT-348/ARC-54

1 and 4 are open. Contacts 3 and 5, and 6 and

7 are as shown.

are checked by the test set. These functions

b. Transmit and Receive Audio Test. Transmit

i n c l u d e frequency selection, transmit and

receive audio operation, squelch control, and

audio is applied from a headset-microphone con-

homing operation. Test jacks on the front panel

nected to HEADSET jack J9 on the test set to

of the test set facilitate connection of the test

pin 3 of jack J9. From pin 3 of jack J9, transmit

equipment to the various circuits under test.

audio is applied to audio amplifier A1. Amplifier

a. Frequency Selection. The frequency selec-

circuits of transistors A1Q1, A1Q2, and A1Q3

tor on the test set simulates the frequency con-

amplify the transmit audio and route it to emit-

t r o l function normally obtained from the

ter follower A1Q4. From the emitter follower

C-3835/ARC-54 for operating the tuning circuit

A1Q4, transmit audio routes through contacts

in the RT348/ARC-54. The functions simulated

2 and 5 of RCVR/XMTR FUNCTION switch S9B

1-6