SECTION 2. AN/GRC-103 CONTROLS AND INDICATORS
a. Components of AN/GRC-103. The AN/GRC-103 provides three basic functions.
First, it has the capability of transmitting baseband information developed from multichannel
telephone equipment. Second, it is capable of reception and demodulation of FM signals; it will
also regenerate baseband signals. Lastly, an order wire and signaling facility is provided for
Open Fold-Out 10 at the end of this booklet and refer to it while reading the following
The radio set is divided into three areas, one for each of its functions. Signal
transmission is accomplished with the two bottom components. The two receiver components
are located directly above the transmitter and the order wire is located above the receiver.
b. Transmitter Controls and Indicators. The transmitter fixed head and the transmitter
RF head are the two transmitter components. Either component may be removed from the case
by loosening four screws. The controls and indicators located on the transmitter fixed head
along with their functions are listed on the following pages. Become familiar with the location
of the transmitter fixed and RF heads on your job aid card.