User's Manual

Modulation Deviation Adjustment
1. Connect a power meter, modulation meter and oscilloscope to radio.
2. The radio should be programmed to contain a channel with a frequency in the middle the band of
interest with an RF power setting of 1 W.
3. Switch the data radio ON.
4. Inject a 1Vrms(3VP-P) SINE wave signal at a frequency of 100Hz into pin 1 of J501
5. Set the data radio to TX
6. Observe the oscilloscope display to check that the 100Hz tone is a square ware by tuning RV502.
7. Whilst observing the oscilloscope, adjust the deviation and balance potentiometers. RV501 and
RV502 to obtain a good square at the following deviation:
12.5 kHz channel spacing <= 2.5 kHz dev
6.25 kHz channel spacing <= 2 kHz dev
8. It may be necessary to alternate the adjustment of the two potentiometers.
9. Sweep the signal generator between 100Hz and 3kHz. Record the peak deviation.
The peak deviation should be as above. If necessary adjust the potentiometers to achieve this.
10. Switch to RX.
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