Comnet MLS II MLSH041, Руководство по обслуживанию

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ALIGNMENT AND TROUBLESHOOTING PROCEDURES LBI-38425A
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5.1.4 Receiver Frequency Adjustment
1. No receiver frequency adjustment is required.
2. With proper alignment of EX injection frequency, RX injection frequency will
automatically be correct.
5.1.5 Modulation Level Adjustment
Procedure for synthesizer Transmit Deviation
1. Select the highest frequency channel.
2. Rotate CG DEV ADJUST, RV202 fully counterclockwise.
3. Connect the audio oscillator and apply a 1 kHz tone at 850 mVrms to MIC HI, J701-
4. Connect the deviation monitor to the antenna connector, J1 through a 30 dB
decoupler. Key the radio. Set DEV ADJUST, RV201 for ±3.75 kHz deviation.
4. Set RV202 fully clockwise. Remove P602 from position 1-2 and set aside. Apply a
400 Hz tone to J602-2 and with the radio keyed, vary its amplitude until the
Deviation Monitor reads 2 kHz. Note the level.
5. Change the audio oscillator frequency for a 10 Hz tone at the same level and set
LOOP MOD ADJUST RV203 for a deviation of 2 kHz. Unkey the radio.
6. Disconnect the audio oscillator and replace P602 in position 1-2.
7. Select a frequency with Tone Channel Guard.
8. Key the radio and set CG DEVIATION ADJUST RV202 for a deviation reading of
±0.75 kHz.
NOTE
If channel guard is not used on any frequency channel, CG DEV ADJUST, RV201,
may be set for ± 4.5 kHz deviation instead of ±3.75 kHz.
5.1.6 Audio Check
Audio Sensitivity
1. Connect audio oscillator output to MIC HI, J701-4. Adjust output for 1 kHz at 1
Vrms.
2. Reduce oscillator output until deviation monitor indication falls to ±3.0 kHz for
radios without Channel Guard or to ± 2.25 kHz for radios with Channel Guard.
Oscillator output voltage should be less than 120 millivolts.