Service Manual

26
Tx frequency tolerance, VCO lock voltage adjustment, maximum deviation and modulation
sensitivity
Note: These items are adjusted outside the adjustment mode (unnecessary to enter the adjustment
mode) via the hardware adjustment.
Tx low power, Tx high power, CDCSS waveform, CDCSS deviation, CTCSS deviation (low),
CTCSS deviation (high) and Tx low voltage threshold
Note: These items are adjusted inside the adjustment mode via the software adjustment.
Rx
VCO lock voltage adjustment (outside the mode), squelch, Rx bandpass filter, Rx low voltage
threshold
Specific Operations and Requirements
Conventional Adjustment Items (outside the adjustment mode): Tx frequency tolerance, VCO
voltage adjustment, maximum deviation, modulation sensitivity.
Note: The configuration file has preset CH1, CH2 and CH3 as wide band with low, medium and
high frequency respectively and CH4, CH5 and CH6 as narrow band with low, medium and high
frequency respectively. Make sure the antenna or load is connected before adjusting.
Measurement Adjustment
Adjustment Item Condition
Test Equipment Test Point Part Method
Specifications/
Remarks
Tx frequency
tolerance
Rotate to
CH2. Press
PTT to
transmit.
Radio
communication
test set
Antenna VR300
Adjust VR300 with a
ceramic alignment
screwdriver to limit
the center frequency
to the error range.
≤150Hz
Rotate to
CH1. Press
PTT to
transmit.
Adjust TC100 with a
ceramic alignment
screwdriver until the
lock voltage is within
the required range.
0.7V （+0.1V）
Tx VCO
lock voltage
Rotate to
CH3. Press
PTT to
transmit.
TC100
Check
≥2.3V
Rx VCO
lock voltage
Rotate to
CH1.
Digital voltmeter
CV
TC101
Adjust TC101 with a
ceramic alignment
screwdriver until the
0.7V （+0.1V）