TM 11-6625-2632-14-1
h. Earphone Test.
(3) If meter indicated in the green area briefly
(1) Perform the procedures given in g (1) and
during whistle, voice power output is satisfactory.
NOTE
(2) above.
It is normal for the meter indication to fall
(2) Observe the noise level from the speaker of
the receiving radio.
back into the red area if the microphone is
not held close to the mouth for full sound
(3) Plug the earphone connector into the
volume.
earphone jack of the receiving radio. The speaker
of the receiving radio should now be silent and the
(4) If meter indicated in the red area through-
receiver noise should be clearly in the earphone.
out the test, voice power output is not satisfac-
(4) If the earphone does not operate properly,
tory. Repeat the test carefully. If meter still does
check the earphone connection for dirty contacts.
not indicate in the green area, higher category
If cIeaning the contacts does not correct the
repair of the transmitting radio is required.
d. 121.5 MHz Beacon Transmit and Beacon
problem, replace the earphone. If operation is still
Monitor Test.
unsatisfactory. the receiving radio is unsuitable for
use and higher category repair is required.
(1) Set the frequency selector on the test set
i. Completion of Tests.
to 121.5 MHz.
(1) Satisfactory completion of the tests in b
(2) Set the transmitting radio set to transmit
through h above assures the transmitting radio set
a beacon signal at 121.5 MHz.
(3) Meter should indicate in green area to
is operating properly as a transmitter and the
indicate beacon power output is good. If meter
receiving radio set is operating properly as a
indicates in red area, the radio set is not suitable
receiver.
f o r use and higher category maintenance is
(2) Interchange the two radio sets and repeat
required .
the test procedures in paragraphs b through h
(4) A beacon tone should be barely audible in
above. Satisfactory completion of the tests assures
t h e speaker of the transmitting radio. If the
both radio sets are operating properly.
b e a c o n tone is not audible, higher category
(3) Disconnect the cable assemblies from the
maintenance of the transmitting radio is required.
radio sets.
e. 121.5 MHz Voice Transmit Test.
(4) Remove the test adapters from the radio
(1) Press and hold the PUSH-TO-TALK
sets.
but ton on the transmitting radio set.
(5) Check that the threads of the antennas and
( 2 ) Whistle a steady clear tone into the
antenna jacks are free of moisture, dirt or other
microphone of the transmitting radio set from a
CAUTION
distance of 2 to 3 inches and observe the meter on
Do not overtighten or the plastic threads
the test set. Release the PUSH-TO-TALK button.
(3) If meter indicated in the green area briefly
on the antenna will be damaged.
during whistle, voice power output is satisfactory.
(6) Install the antennas and antenna sealing
washers. Avoid cross threading. Use only enough
NOTE
torque to compress the sealing washer slightly.
It is normal for the meter indication to fall
( 7 ) Replace test set items removed in
back into the red area if the microphone is
paragraphs 2-8 a and d.
not held close to the mouth for full sound
volume.
(4) If meter indicated in the red area
a. General.
(1) Perform the procedures outlined
in
throughout the test, voice power output is not
satisfactory. Repeat the test carefully. If meter
still does not indicate in the green area, higher
(2) Perform the AN/PRC 106 tests in the
c a t e g o r y repair o f the transmitting radio is
order indicated.
required.
b . 243.0 MHz Beacon Transmitter, Beacon
f. 243.0 MHz Receiver Test.
Monitor, and Battery Test. Perform the
NOTE
procedures outlined in paragraph 2 9b.
c. 243.0 MHz Voice Transmit Test.
The transmitting radio must pass the tests
in b through e above before the receiver
(1) press and hold the PUSH-TO-TALK
button on the transmitting radio set.
tests are performed.
(1) Set the volume control of the transmitting
( 2 ) Whistle a steady clear tone into the
microphone of the transmitting radio set from a
r a d i o to minimum and the function switch to
distance of 2 to 3 inches and observe the meter on
transmit a beacon signal at 243.0 MHz.
the test set. Release the PUSH-TO-TALK button.
(2) Set the function switch of the receiving
