Ericsson MGM 450, Руководство по обслуживанию

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PERFORMANCE TEST
TRANSMITTER PERFORMANCE TEST
Power Output
1. Set the power supply voltage to 13.8 VDC (measured at the radio during transmit).
2. Connect an RF watt meter and dummy load to the antenna receptacle.
3. Press the PTT switch.
4. Verify that the output is at least 40 watts.
5. Reduce the power supply voltage to 11 volts.
6. Verify that the output is at least 15 watts.
7. Release the PTT switch.
Audio Response
1. Connect an audio generator to the microphone jack on the radio. Set the generator for a frequency of 1 kHz.
2. Connect a communication service monitor to the RF output of the radio through a power attenuator. Set the
monitor to read average peak FM deviation.
3. Press the PTT switch.
4. Adjust the audio generator level to produce 1 kHz deviation.
5. Set the audio generator frequency to 2 kHz. The transmitter deviation should be approximately 2 kHz.
6. As the audio generator frequency is varied from 300Hz to 10 kHz, the deviation should increase until it
reaches a maximum at an audio frequency of 2.5 kHz to 2.9 kHz. At higher frequencies, the deviation
should decrease. the deviation at an audio frequency of 6 kHz should be less than 1 kHz.
7. Release the PTT switch.
Limiting Test
1. Set the audio generator frequency to 1 kHz.
2. Press the PTT switch and adjust the generator level to produce 1 kHz deviation. Note the generator level.
3. Increase the audio generator level by 20 dB (factor of 10 times).
4. Sweep the audio generator over a frequency range of 300Hz to 3 kHz. the deviation should not exceed
±
1kHz within this range.
5. Release the PTT switch.
MONOGRAM SERIES LBI-38865
PERFORMANCE TEST
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Nov. 94