SYSTEM TROUBLESHOOT AN/PRC-104(A) AND AN/GRC-213
TO A DEFECTIVE COMPONENT, CABLE, OR ACCESSORY AND REPAIR
of this lesson, you will be able to troubleshoot the AN/GRC-
213 radio set
to a defective component, cable, or accessory using the
(See Figures 26
to 32.)(See Figure 33 for AN/PRC-104(A).)
This lesson is based on TM 11-5820-923-12 and other material approved for US
However, development and progress render the text
continually subject to change. Therefore, base your examination answers on
material presented in this lesson rather than on individual or unit
confirmed by the organizational mechanic performing an EPC to verify a
fault. Once a fault is verified, the organizational mechanic's job becomes
system troubleshooting to a replaceable or repairable unit. The AN/GRC-213
radio set is made up of four major replaceable components plus loudspeaker,
handset, antenna, key, and interconnecting cables.
b. The four major replaceable components of the AN/GRC-213 are:
The RT-1209/URC, which determines frequency and provides RF
output as a transmitter or provides detection of an RF signal to
an audio output as a receiver.
The AM-7152/GRC-213, which controls power to the system and
interfaces the AN/GRC-213 to the AN/VIC-1 intercommunication
system for those radios installed in tracked vehicles.
The AM-6874 amplifier-coupler, which amplifies the RF signal to
the 20-watt output for transmission and controls antenna coupling
to the RT.
The switching unit, a part of the mount for the AN/GRC-213 radio
set, which provides the necessary switching to make the radio set
compatible with the several antenna systems available to users of
c. There are three antennas furnished with the AN/GRC-213 radio set,
217A/PRC is a 10-foot whip which screws into AB-129/PR (shock mount) for
direct use as an AN/PRC-104(A) radio set (a part of AN/GRC-213 radio set).
Antenna AS-2259/GR (NVIS) antenna is furnished with each AN/GRC-213 radio
set for NVIS transmission. The antenna group AN/GRA-50 is furnished as the
The antenna AB-1322 with mast sections is furnished with