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 5 W.
3. Switch the data radio ON.
4. Inject a 106mVrms SINE wave signal at a frequency of 1000Hz into pin 1 of J903,
Set the data radio to TX Observe the oscilloscope display to check that the 1000Hz tone
is a sine wave by tuning VR201and set deviation is 3.5KHZ.
5. Using the AF signal generator, sweep from 100 Hz to 3 kHz and record the peak
deviation.
Check the peak deviation for appropriate channel spacing as follows：
12.5 kHz channel spacing<= 2.5 kHz dev
20 kHz channel spacing<= 4 kHz dev
25 kHz channel spacing<= 5 kHz dev
6. Switch to RX.
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