Test Procedure Information

TM 11-5821-277-20

column and perform the corrective actions listed.

services charts (paras 4-4 through 4-9) outline

inspections and tests to be performed at specific

ed.

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-

indications.

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-

NOTE

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

aircraft.

4-5. Test Procedures

If result is abnormal

Normal result

Item No.

Procedure

Set aircraft master power switch

None.

on.

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

None.

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

frequency.

window.

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-

MI. station.

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.

4-2