CHAPTER 3. DS AND GS MAINTENANCE AMPLIFIER-POWER SUPPLY GROUP OA-3633(*) /GRC

TM 11-5820-498-35

CHAPTER 3

DS AND GS MAINTENANCE

AMPLIFIER-POWER SUPPLY GROUP OA-3633(*) /GRC

NOTE

Throughout these procedures, receiver-trans-

mitter refers to Receiver-Transmitter, Radio

RT505/PRC-25 which is used in Radio Sets

AN/VRC-53 and AN/GRC-125, and to Re-

ceiver-Transmitter, Radio RT-841/PRC-77

which is used in Radio Sets AN/VRC-64 and

AN/GRC-160. Both receiver-transmitters

a r e used with Amplifier-Power Supply

Group OA-3633(*)/GRC which is also part of

these radio sets.

Section I. GENERAL TROUBLESHOOTING TECHNIQUES

3-1. Scope of DS and GS Maintenance

AM-2060(*)/GRC is covered in Paragraphs 3-8,

a. The maintenance procedures in this chapter

3-9, and 3-10. Some faults, such as burned out

are applicable to DS (direct support) and GS

resistors, arcing, and shorted relay coils and

(general support) maintenance facilities and sup-

transformer windings can often be located by

plement the organizational maintenance proce-

sight, smell, or hearing. The majority of the

dures described in TM 11-5820-498-12 for the

faults, however, must be isolated by checking

OA-3633(*)/GRC. The systematic troubleshoot-

voltages and resistances.

ing procedures which begin with the operational

b. Visual Inspection. The purpose of visual

and equipment performance checks that can be

inspection is to locate faults without testing or

performed at an organizational maintenance level

measuring circuits. All visual signs should be ob-

are carried to a higher level in this chapter.

served and an attempt made to localize the fault

b. Refer to paragraph 1-lb for a listing of

to a particular area.

publications that cover the DS and GS mainte-

c. Testing Procedure. After any repair of the

nance level of the components that are part of

CX-4655/GRC or AM-206(*)/GRC, always test

t h e AN/VRC-53, AN/VRC-64, AN/GRC-125,

it for satisfactory performance of all circuits be-

and AN/GRC160.

fore returning the equipment to the user or plac-

c. Refer to paragraph 1-1c for a listing of pub-

ing it in repaired stock. Refer to paragaphs 3-16

lications that cover the DS and GS maintenance

through 8-21 for inspection and testing proce-

level of the equipment that is used in conjunction

dures. The procedures can also be used to check

with these radio sets.

the performance of the equipment before starting

to troubleshoot it.

3-2. Organization of Troubleshooting Proced-

ures

3-3. Test Equipment, Tools, Materials, and

a. General. The first step in servicing a defec-

Power Sources Required

tive OA-3633*/GRC is to localize the fault by

a. Test Equipment Required.

tracing the trouble to the CX-4655/GRC or to

Publication

Item

some part of the AM2060(*)/GRC. The second

step is to isolate the fault. Isolation means trac-

Multimeter ME-26(*)/Ua . . . . . . .

TM 11-6625-200-15

TM 11-6625-683-15

Generator, Signal AN/URM-127

ing the fault to a defective part responsible for

Voltmeter, Electronic

the abnormal operation. Isolating a fault to a de-

M E - 8 0 ( * ) / U b . . . . . . . . . TM 11-6625-820-12

fective part on the plug-in assembly of the

Change 2

3-1