Repair Procedures

TM 11-5820-509-35

prior to attachment of the front panel to the main chassis

(10) Loosen and remove the four 6-32 x 3/8

or RT-671/PRC-47.

flat head screws that attach the POWER AMPLIFIER

LOAD-TUNE chart cover to the front panel of the

(3) Assemble the front panel to the main

receiver-transmitter.

chassis as follows:

(11) Refer to figure 3-91. Loosen setscrews

(a) Refer to figure 3-92. Bring the front

(9) and withdraw fiber shaft (2), shaft collar (10), spur

panel close to the front of the main chassis and install

gear (8), and washer (7) from the plate capacitor switch

OPR-TUNE switch (44) in its appropriate location using

assembly. Remove panel bushing (6) and then loosen

washers (45) and (46), and nut (3).

and remove 6-32 x 1/2 flat head screws (1) and (3) that

secure the switch assembly to the front panel.

NOTE

Be sure that the key of washer (46) is

(12) Loosen and remove the three 6-32 x %

properly seated in the pilot hole in

flat head screws that secure the relay bracket around

the front panel before hex nut (3) is

the SMTR PWR switch assembly on the front panel of

tightened.

the receiver-transmitter.

(13) Loosen and remove the nine 8-32 x I/2

pan head screws and the associated washers and nuts

(b) Carefully insert the shafts of XMTR

that secure the main chassis to bosses on the rear of the

POOR, POWER AMPLIFIER LOAD, and POWER

front panel (three screws at each end and three in the

AMPLIFIER TUNE controls, the shafts of the two upper

center).

load inductors, the AUDIO connector, VOLUME control,

POWER-LIGHTS switch and POWER connector into

(14) Cut the nylon lacing cord that secures the

their mounting holes; do not secure in place until

cable harness to the center boss at the extreme right

instructed to do so.

end of the front panel.

(15) Carefully remove the front panel from the

NOTE

chassis assembly releasing individual components as

Before continuing this procedure,

the panel is slowly withdrawn.

assure that the nylon bushings

(16) Remove any other panel-mounted

associated with the shafts of POWER

components that are required to repair the front panel.

AMPLIFIER LOAD and POWER

(Disassembly of the frequency selection mechanism is

AMPLIFIER TUNE controls are

detailed in paragraph 3-16.)

properly seated in the panel

(17) Remove lower front contact spring

bushings.

assembly and upper front contact spring assembly using

the detailed procedure listed in steps (11) and (12) of

paragraph 3-15a.

pan head screws in opposite ends of the main chassis

b. Repair Procedures.

Replace any defective

side panels so that the front panel components can be

panel-mounted component or individual piece part

secured in place easily; do not attach washers and nuts

removed to affect repairs. Individual parts located in the

to these screws.

main chassis should be replaced only if they are

(d) Refer to figure 3-92. Install washer

defective. Component parts are shown on the main

(8) and hex nut (6) on the shaft of X MTR PWR switch

chassis schematic diagram (fig. 7-8) and are located in

(S103) and tighten securely. Then install and tighten

figures 3-64 through 367.

the 6-32 x 1/2 flat head screws (7), (9), and (10) that

secure switch bracket (24) to the front panel.

CAUTION

(e) Install and tighten the circular nuts

When using a soldering iron to

and hex nut that secure the AUDIO and POWER

remove or replace component parts,

receptacles to the panel.

use only enough heat to cause

(f) Install the washer and hex nut that

solder to flow. Excess heat can

secures the VOLUME control and POWER-LIGHTS

damage the component and may also

switch to the front panel; tighten them securely.

damage its associated terminal or

mounting board.

(g) Install the remaining 8-32 x 1/2 pan

head screws in the side panels of the main chassis;

secure all nine screws (3 at each end and 3 in the

c. Reassembly Procedures.

center) using the appropriate washers and nuts.

(1) Install

individual

panel-mounted

(4) Install the knobs on XMTR POOR, M A

components that have been removed for repair. (See

DJ, VOLU M E, and POW ER-L I G H TS controls.

paragraph 3-16c for detailed assembly procedures of

Orient each knob properly before tightening the

the frequency selection mechanism .)

setscrews.

(2) Perform all internal repair and reassembly

procedures required by paragraphs 3-15 through 3-18

3-115