PRELIMINARY SETUP. Now that you have learned how to install the radio set and where the operator's
controls and indicators are, you are ready to perform the preliminary setup of the AN/PRC-104. Set the radio set
controls as follows:
Turn MODE switch to V-TR.
Turn ANT SEL switch to WHIP connection position.
Set FREQUENCY to a frequency authorized by your frequency manager.
Turn sideband select switch to USB.
Turn VOLUME control clockwise to apply power, and set to desired listening level. (If a clicking
sound is heard, this indicates a weak battery [20 V or less, replace battery]).
Press PTT button on the handset. The radio set will do its tuning procedure.
10. TEST PROCEDURES. When the radio has concluded its tuning procedure, you will be ready to begin
operating the radio set. You should perform an operational test on the radio at this point. The test procedures are
Change frequency by at least 1 kHz; then momentarily press the handset PTT switch.
Listen for a 1-kHz tune tone. (Tuning is brief; it may be 3 to 12 seconds.)
Tune tone should terminate within 12 seconds. This indicates the automatic antenna tuner is operating
normally. A continuous, rapid beeping sound in the handset indicates failure of the radio to properly
tune (a tuning fault exists).
Transmit by using the handset. Press the PTT switch, and communicate with another radio set on the
test frequency. The presence of sidetone in the handset earpiece indicates transmission is satisfactory.
(If fault tone occurs, refer to the radio troubleshooting procedure.)
Repeat the above procedures for test frequencies, spaced through the 2- to 30-MHz part of the radio
spectrum to test the auto tune feature. These frequencies can be obtained from your frequency
Select a frequency for the time standard broadcast (multiples of 5 MHz; e.g., 5, 10, 15, 20 MHz). For
this test, one frequency may be better than another depending on the time of day and station. You may
not hear these stations if you are located outside the United States.
Some frequencies may not work at all, so try several if necessary to get a good signal.