CHAPTER 5. DEPOT MAINTENANCE

TM 11-5820-509-35

CHAPTER 5

DEPOT MAINTENANCE

5-3. Equipment Adjustments

5-1. General

The following instructions detail complete module and

a. Instructions are included in this chapter that

subassembly electrical adjustments and calibrating

detail the adjustment, alignment, and bench checkout of

procedures to assure that the receiver transmitter meets

the separate subassemblies of the receiver-transmitter

the performance requirements specified by the original

before re-installation of these modules in the radio set

procurement document.

following overhaul procedures.

Several receiver-

transmitter tests are included in this chapter that cannot

5-4. Transmit Mixer Balance and Transmitter Gain

be performed at lower echelon activities because of the

peculiar test equipment requirements.

Control Adjustment

b. The trouble isolation sections of chapter 3

(fig. 5-1)

describe in detail the procedures necessary to isolate

a. Test Equipment and Material.

trouble within the modules and subassemblies of the

(1) Spectrum Analyzer AN/UPM-110

receiver-transmitter.

The general replacement

(2) Converter, Hewlett-Packard K15-8551B

techniques contained in paragraph 3-8 apply equally to

(3) Dummy Load DA-75/U

the depot maintenance level.

(4) Attenuator (see fig. 5-1)

(5) Multimeter ME-26A/U

(6) Primary power source: 115-volt, 400-Hz,

CAUTION

single-phase, 3 amp.

Remove all power from Radio Receiver-

b. Test Conditions and Equipment Connections.

Transmitter RT-671/PRC-47 before beginning

(1) Connect the test equipment to Radio

any repair procedures.

Receiver-Transmitter RT-671/PRC-47 as shown in

figure 5-1. Do not connect ME-26A/U until instructed to

5-2. Replacement of Parts

do so.

a. Parts removal and replacement techniques are

(2) Connect the primary power source to the

described in paragraph 3-9 of this technical manual.

receiver-transmitter.

b. Removal and replacement of the plug-in

(3) Turn on the test equipment and place the

modules and subassemblies of the receiver transmitter

POWER-LIGHTS switch on RT-671/PRC-47 to POWER

are provided in paragraph 3-12.

ON. Permit the equipment to stabilize for at least 5

c. Module disassembly and reassembly techniques

minutes before beginning the procedures listed in the

are listed in paragraph 3-13.

chart below.

d. Mechanical subassemblies are disassembled

and reassembled using the procedures detailed in

paragraphs 3-15 through 3-19. No further special

instructions are required in connection with these

subassemblies and modules.

Figure 5-1. Transmit Mixer Balance and Transmitter Gain Control Adjustment, Equipment Setup.

5-1