Table 4-7. TESTING RECEIVER CIRCUITS TEST PROCEDURE

TM 11-5895-1141-34

Step

Operation

Normal Indication

Preliminaries. The receiving circuits are tested by applying an audio

signal to the received signal pins of the selector unit connectors J201,

J202. The resulting signals between the sleeve terminals of the headset

jack pair (J301, J302) on the jack -panel are then measured. Before

proceeding with the tests, perform the preliminary adjustments of 1a

through 1e.

a. Connect-external power source.

Power light is on.

Depress Power switch.

b. Set S1002 (LOCK/NONLOCK) of first selector module to off (center)

position. See the selector unit, front panel, figure 4-1.

c. Set S1001 (HEADSET-LOUDSPEAKER switch) of first selector

module to HEADSET position.

d. Regulator jumper (E1121 to E1122 in volume control module) must

be in place. See circuit board figure 4-2.

e. Turn HEADSET and SPEAKER volume controls in the audio unit to

maximum position. See audio unit, front panel, figure 4-3.

4-7