Technical data

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Chapter 4, Test, Parameter, and Pass/Fail Limit Descriptions

TEST_06. TX Audio Distortion

This test measures the audio-frequency harmonic distortion, which is the change

in harmonic content of the input signal as a result of passing through the audio and

RF circuits of the transmitter. Audio connections from the radio to the test set are

required for this test.

The 400 Hz High-Pass Filter is used by this test if Option 010 is installed in the

test set.

Transmitter audio distortion is measured in percent.

If your radio has Continuous Digital-Controlled Squelch System (CDCSS), the

added signal can cause this test to fail. In this case, disable the CDCSS circuitry.

If your radio has Continuous Tone-Controlled Squelch System (CTCSS) or

Continuous Digital-Controlled Squelch System (CDCSS) available but is not

controllable, an alternate filter may be selected, if available, to reduce the effect of

the tone or code on the result. A 400 Hz HPF, C MESSAGE, or CCITT filter may

be selected.

Pass/Fail Limits Used

Pass/Fail Limit 19, TX Audio Distortion

Test Parameters Used

Parameter 2, RT Full Rated System Deviation

Parameter 20, TX Audio Distn % Full Rated System Dev

Parameter 27, TX De-emphasis

Testing Conditions Defined by the Software

• Audio distortion is measured at 40% of the rated system deviation and at a 1 kHz rate.