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GNS 400W Series Maintenance Manual
Page 4-43
190-00356-05
Rev. A
5.
Adjust the microphone audio signal level for 70% modulation. If the microphone audio
drops below 100 mV and the unit still shows 70% modulation or greater, stop the test and
record as a test failure. If test passes, proceed.
6.
Record the reference input level.
7.
Unkey the microphone.
8.
Set the audio test signal to 350 Hz at the recorded reference input level.
9.
Key the microphone.
10.
Measure the modulation level in dB and record as reference.
11.
Measure the AM depth in dB while sweeping the audio signal from 400-2500 Hz in 100
Hz steps.
12.
Record the max and min levels.
13.
Unkey the microphone.
14.
Verify that the difference between the max and min values is
≤
6 dB.
