RETRANSMIT OPERATION. - TM-11-5820-670-300068

TM 11-5820-670-30

1-54. RETRANSMIT OPERATION.

NOTE

This paragraph contains a discussion of retransmit operation. Not to duplicate other

areas of the manual, the received and transmitted signals are not traced through the

receiver-transmitter circuitry. Detailed interconnection of the radio sets and associated

equipment operating in the retransmit mode is shown on FO-8.

To follow the simplified interconnection of two radio sets operating in retransmit mode, see FO-9 while

reading this paragraph.

Two AN/ARC-131 Radio Sets, tuned to different frequencies, maybe interconnected and operated as

an unattended two-way relay station. The first radio set receiving a signal keys the transmit circuits of

the second radio set and couples the received signal into the second transmitter for retransmission.

The relay station maybe operated in either carrier squelch or tone squelch mode.

NOTE

SQUELCH disable mode (DIS) cannot be used for retransmit operation.

The radio set transmitter control circuits are interlocked by squelch relay K5502 to ensure that the two

radio sets will not transmit simultaneously. FO-9 is a simplified block diagram showing the squelch

relays in their deenergized condition. When the relays are deenergized, both radio sets are in receive

node with no signal received.

RETRANSMIT CIRCUIT, STATIC CONDITION

The radio sets are in the static condition when no signals are being received or transmitted. Both

squelch relays (K5502) are deenergized since no carrier or tone signal is present in either radio set.

With these relays deenergized, retransmit control groundpaths are open and both transmitters are

deactivated.

RETRANSMIT CIRCUIT, DYNAMIC CONDITION

When a signal is received by radio set no. 1, the signal Ievel in the radio set causes squelch dc

amplifier Q5207 to conduct, thereby energizing squelch relay K5502.

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