TM 11-6625-2632-14
NOTE
NOTE
The
presence
of
an
audible
To turn the knob of the function
interfering signal from the speaker
switch to the VOICE 282.8 position,
caused by a nearby 243.0 MHz
press the button in the center of the
transmitter generally will be a GO
knob while turning the knob in a
condition. This may not be a true
counterclockwise direction.
indication
if
the
interfering
transmitter is of unusually higher
b. Observe the noise level from the speaker of the
power or its antenna is located within
receiving radio.
100 feet.
c. Plug the earphone connector into the
EARPHONE JACK of the receiving radio. The speaker
2-14. 282.8 MHz Receiver Check
of the receiving radio should now be silent and the
a. Using a transmitting radio known to be operating
receiver noise should be heard clearly in the earphone.
properly, set its function switch to the VOICE 282.8
d. If the earphone does not operate properly (c
position and its VOL control at minimum. Set the
above), check the earphone connection for clean
function switch of the receiving radio to the VOICE 282.8
contacts. If this does not correct the problem, replace
position and its VOL control at MAX.
the earphone and cord assembly. If operation is still
NOTE
improper, replace the receiving AN/PRC-90.
To turn the knob of the function
switch to the VOICE 282.8 position,
2-16. Completion of Tests
press the button in the center of the
knob while turning the knob in a
through 2-15 with all GO indications assume that the
counterclockwise direction.
transmitting radio set is operating properly as a
b. Press the PUSH TO TALK button on the
transmitter, and the receiving radio set is operating
transmitting radio. A reduction in noise level from the
properly as a receiver. Disconnect the transmitter cable
speaker of the receiving radio indicates a satisfactory
and receiver cable and reconnect them with the radio
282.8 MHz receiver.
sets reversed.
c. Complete lack of noise, or no change in noise
level indicates a NO-GO condition.
Replace the
through 2-15. If the testing is completed with all GO
receiving AN/PRC-90.
indications, both radio sets are operating properly as
NOTE
transmitters and as receivers.
The
presence
of
an
audible
c. Disconnect the transmitter cable and receiver
interfering signal from the speaker
cable from the radio sets. Be sure the threads of the
caused by a nearby 282.8 MHz
transmitter generally will be a GO
other contaminants. Install the antennas and antenna
condition. This may not be a true
sealing washers. Avoid cross threading of the antennas.
indication
if
the
interfering
Use the wrench (fig. 2-1) to tighten each antenna to its
transmitter is of unusually high
case with just enough torque to compress the washer
power or its antenna is located within
slightly.
100 feet.
CAUTION
Do not overtighten or the plastic
2-15. Earphone Check
threads on the antenna will be
a. Using a transmitting radio known to be operating
damaged.
properly, set its function switch to the VOICE 282.8
d. Place the wrench and instruction manual in the
position and its VOL control at minimum. Set the
cover (fig. 1-2) of the test set. Disconnect the two
function switch of the receiving radio to the VOICE 282.8
connector adapters and place them in the test set. Stow
position and its VOL control at MAX.
the cables and close the cover.
2-5
