column and perform the corrective actions listed.
services charts (paras 4-4 through 4-9) outline
inspections and tests to be performed at specific
intervals. The inspections and tests are made to
c. Two personnel are required to perform cer-
maintain Army electronic equipment in a com-
tain portions of the test: one man operates the
bat-serviceable condition; that is, to maintain the
push-to-talk switch and speaks into the micro-
equipment in good general (physical) condition;
phone in the cockpit of the aircraft, while another
and in good operating condition. To assist the
man operates the meter selector switch and logs
organizational maintenance repairman in main-
the meter indications at the transceiver location.
taining combat serviceability, the charts indicate
d. The meter indications listed are typical and
what to inspect, how to inspect, and what the nor-
will vary slightly between radio sets, therefore,
mal conditions are; the References column lists
the organizational maintenance repairman should
the paragraphs or manuals that contain supple-
maintain a log of the meter
mentary information. lf a defect cannot be re-
Sudden, drastic changes in meter indications in-
medied by the organizational maintenance re-
dicate that the radio set is malfunctioning or
pairman, higher category maintenance or repair
that radio set operation has deteriorated and
is required. Records and reports of these inspec-
trouble is imminent. In either case, the transceiv-
tions must be made in accordance with the re-
er should be replaced (para 417) and the per-
quirements set forth in TM 38750.
formance check repeated to verify that typical
meter indications are obtained.
4-4. Test Procedure Information
e. The aircraft C1611D/AIC should be used
during performance of the check; otherwise, re-
a. The test precedures given in paragraph 4-
5 should be performed each day the radio
sults will not be valid.
set is to be used, when troubleshooting the equip-
ment, subsequent to removal and replacement
27.5 volts dc must be present on the aircraft
of major radio set components, and subsequent
main & bus during the performance check. To
to initial installation.
Prevent current drain on the aircraft batteries,
b. Perform the checks in the order list-
the aircraft engine(s) should be running or an
ed. When an abnormal result is noted, refer to
auxiliary power unit should be connected to the
the reference Iisted under If result is abnormal
4-5. Test Procedures
If result is abnormal
Set aircraft master power switch
Para 4-13, item L
Energize 27.5-volt dc circuit
Panel lamps should light, illuminating
panel markings on control Unit.
breakers that supply power
to radio set, and C-1611D/AIC
associated with radio act.
Set controls on C-1611D/AIC
as neceassry to enable opera-
tion of radio act.
Para 4-13, item 76.
Indicators in VHF COMM frequency
Set control unit OFF-PWR
indicator tuning window should light.
switch to PWR.
Para 4-13, item 6.
Selected frequency should appear in
Tune radio set to predetermined
VHF COMM frequency indicator
Para 4-13, item 9.
Establish two-way voice comm-
a. Transmitted signals should be re-
unication with local am.
ceived clear and audible at local
station operating on fre-
Para 4-13, item 8.
quency selected in item 5
b. When signals are being transmitted,
sidetone monitored by headset
above, and adjust control unit
should be clear and audible
VOL control as necessary to
Para 4-13, item 10.
obtain comfortable listening
c. Signals received from local a.m. sta-
level frown headset.
tion should be clear and audible
Para 4-13, item 15.
Rotate control unit VOL control
Volume of recieved signal should in-
clockwise, then counterclock-
crease where VOL control is rotated
wise while receiving a signal
clockwise, and decreased when VOL
control is rotated counterclockwise.
Para 4-13, item 3.
Depress push-to-talk switch.
Blower in transceiver opermates.