GENERAL SUPPORT MAINTENANCE
Section I. INTRODUCTION
3-1. Scope of General Support Main-
a. General support maintenance includes all
3-2. Test Equipment Required
t h e techniques o u t l i n e d for direct support
Table 3-1 lists the test equipment required for
maintenance plug any special or additional
general support maintenance of Maintenance
techniques required to isolate a defective part.
Kit, Electronic Equipment MK-733/ARC-54 and
The maintenance consists of replacing piece
also lists the associated technical manuals.
parts on audio amplifier Al boards, replacement
of RF power meter Ml, directional coupler DC1,
Table 3-1. Test Equipment Required for General
attenuator/dummy load AT1, blower B1, and
repair of the counter assembly. In some cases,
a trouble can be localized by the general support
Generator, Signal AN/URM-127.
repairman to a particular functional circuit in
the test set or simulator by use of the operating
procedures in the monthly preventive mainte-
Power Supply PP-351/U.
Test Set, Transistor TS-1836/U.
nance c h e c k s and services c h a r t i n T M
Voltmeter, Electronic AN/URM-
116625-601-12. In other cases, however, a trou-
Voltmeter, Electronic ME-30/U.
AN/ARC-54 unit test procedures.
Tool Kit, Electronic Equipment
b. This chapter contains sections concerning:
Radio Set AN/ARC-54.
(2) Repairs and Replacement
Section Il. General Support Troubleshooting
3-3. Troubleshooting Procedures
a. Voltage Measurements. The voltage read-
ings in table 32 were obtained under the condi-
For troubleshooting procedures at the general
tions specified below. A l w a y s make voltage
support maintenance category, follow the steps
measurements under these same conditions or
the readings obtained may be inaccurate. Make
3-4. Voltage and Resistance Measure-
all voltage measurements with a vtvm that has
an input impedence of at least 10 megohms
(Voltmeter, Meter ME-30A/U, or equivalent).
Normal voltage and resistance measurements
Connect the dc common clip to the ac ground
taken at the base, collector and emitter of the
clip of the vtvm to chassis ground of the unit
b l o w e r inverter (part of Test Set, Radio
under test. Voltage measurements for blower
TS-967/ARC-54), are presented in the table in
paragraph 3-5. Voltage and resistance measure-
TS-1967/ARC-54) are taken by following the
ments of the audio amplifiers in the test set and
procedures outlined below:
simulator are presented in the tables in parag-
(1) Apply +27.5 volts dc to POWER jack J32.
(2) Set the POWER circuit breaker to ON.
When measuring voltages, use tape or
( 3 ) Set XMIT-RCVR-PTT switch S6 to
s l e e v i n g (spaghetti) to insulate the
entire test prod, except for the extreme
( 4 ) Set TEST FUNCTION SELECTOR
tip. A momentary short circuit can ruin
switch S11 to TEST SET.