Table 4-7. TESTING RECEIVER CIRCUITS TEST PROCEDURE (Cont'd)

TM 11-5895-1141-34

Step

Operation

Normal Indication

Reconnect the audio oscillator. Remove

An output level of 1.1 v minimum should be

the short circuit of step 6. Adjust the

obtained across the loudspeaker; record the

oscillator for 1000 Hz, 155 mv input.

output level.

Remove the ac voltmeter from the 600 ohm

load and place it across the loudspeaker

voice coil in the audio-unit. Set the

receive select switch to the Loudspeaker

position.

NOTE

Access for the loudspeaker requires

detaching front panel from the audio unit

chassis by removing the mounting screws.

Connect a distortion meter across the

The percentage distortion should not exceed

loudspeaker and measure the percentage

8%.

distortion at 300 Hz, 1000 Hz and 3000 Hz,

with the signal amplitude at 155 mv for

Measure the output voltage across the

The output voltage should not be more than

loudspeaker terminals at both 300 Hz and

3 dB below the output voltage measured at

3000 Hz using an input signal amplitude of

1000 Hz in step 7.

155 mv.

4-9