TM 9-2350-275-BD
COMMUNICATIONS SYSTEM
SECTION II. General Operating Procedures
11-4. General.
This section contains general operating procedures for the AN/VRC-12 series
radios (AN/VRC-12, AN/VRC-47 and AN/VRC-64) when used in conjunction with the
AN/VIC-1 intercommunications set. TM 11-5830-340-12 lists operating procedures for
the system, but for convenience, the main points have been reproduced here.
a. Normal Radio Operation with AN/VIC-1 Intercommunications Set.
(1) Turn turret power on. Turn MAIN PWR on the AM-1780 to NORM.
This position makes power available to the radio and the aux receiver connected to the
AM-1780. See figure 14-1.
(2) Turn POWER switch on the radio (connected to 3501) to either HIGH or
LOW. This supplies power to the AM-1780.
(3) Turn POWER CKT BKR switch on the AM-1780 to ON. This supplies
power to the AM-1780 and to all control boxes connected to the AM-1780.
(4) Turn INSTALLATION SWITCH on the AM-1780 to OTHER position.
This is the normal position which allows the radio accessories connected to the control
boxes to operate both the radio and the intercom equipment.
(5) Use the RADIO TRANS switch on the AM-1780 to select crew members
allowed to transmit with the radio.
CDR and CREW - if all crew members are allowed to transmit.
CDR ONLY - if only the crew commander is allowed to transmit.
LISTENING SILENCE - if no one is allowed to transmit.
(6) Select the desired loudness of the intercom and radio signals with the
INT ACCENT switch on the AM-1780,
OFF position - both signals have the same loudness.
ON position -the loudness of the radio signals is reduced below the level of
the intercom signals.
(7) TO turn off the AM-1780 and radio equipment, turn the MAIN PWR
switch on the AM-1780 and the POWER switch on the radio to OFF.
b.
Normal Intercom Operation with the AN/VIC-1 Intercommunications Set
without radios.
(1) Turn turret power on. Turn MAIN PWR switch on the AM-1780 to INT
ONLY. Power is now available for only intercom equipment. See figure 11-1.
(2) Turn POWER CKT BKR switch on the AM-1780 to ON. This supplies
power to AM-1780 and all control boxes connected to the AM-1780.
