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Chapter 2 41

Test Descriptions

TEST_15 - RXA Audio Frequency Response

Description

NOTE

Audio connections from the radio to the test system are required for this

test.

This test measures the ability of the receiver’s audio output circuitry to

follow a

6 dB/octave de-emphasis curve, as well as to follow an audio-bandpass

response. An RF signal with a level specified by parameter 22. RX RF

Level for Signaling (dBm) is applied with a constant deviation. The

modulation rate is swept over the audio frequency-response range in

steps determined by the parameter 23. RXA Audio Response Step

Frequency (kHz).

Receiver audio frequency response is expressed in dB error from a 6

dB/octave curve.

•A

−50 dBm RF signal is applied to the receiver’s antenna.

•The

−50 dBm RF signal is modulated to deviate to 2.9 kHz at a 1 kHz

rate with a SAT tone present and a reference reading is made.

• The frequency rate is then swept over the desired range and the

response measured.

• If the compandor is always on, a 2:1 correction is applied to the

measured results.

• Narrow analog operation uses 1.5 kHz deviation and DSAT.

Pass/Fail Limits Used

• 2. RXA Audio Response Dev From

−

6 dB/oct R1 (dB)

• 3. RXA Audio Response Dev from

−

6 dB/oct R2 (dB)

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Carrier 38TXA Guide Guía de usuario Pagina 41