1.3 Debugging
1.3.1 VCO Modification
Turn off the power saving mode. Set the frequency at the low frequency (see Table 1.2). In
receiving status, test the PD power with the digital multimeter. Adjust the trimming
capacitor C180 to make the PD power at 1V±0.1V.
Set the TX frequency at high frequency, press the PTT button, test the PD power with the
digital multimeter. The power should lower than 3.5V.
1.3.2 PLL Frequency Adjustment
Under the computer test mode, select “frequency tune” option and click “adjustment” to
enter. Adjust the TX frequency among 0~255 to the specified value. (Frequency error
should less than 200Hz.)
1.3.3 TX Frequency Adjustment
Under the computer test mode, select “high power, low frequency” and click “adjustment”
to enter. Adjust the TX power among 0~255 to 4W. And watch the working current and
make sure it not higher than 1.5A.
Adjust “high power, medium frequency”, “high power, high frequency’ to set the TX power
at 4W.
1.3.4 TX Low Power Warning
Adjust the power to 6.8V.
Under the computer test mode, select “the low power threshold”, and click “adjustment” to
enter. Adjust the figure among 0~255 to make the red light flash.
1.3.5 Frequency Deviation Adjustment
Input 100mV, 1000Hz audio signals from the radio MIC, and adjust the potentiometer VR2
to set the TX frequency deviation at ±2.2kHz.
1.3.6 DCS TX Signal Wave Shape and Frequency Adjustment
Under the computer test mode, select “ DCS wide band modulation”, and click
“adjustment” to enter. Adjust the potentiometer VR1, and watch the demodulation signals.
The wave shape should be smooth (close to square wave) and then adjust the figure to
set the frequency deviation at 0.35kHz.
1.3.7 CTCSS Frequency Deviation Adjustment
Under the computer test mode, select “CTCSS wide band modulation”, and click
“adjustment” to enter. Adjust the figure to set the frequency deviation at 0.35kHz.
1.3.8 Receiver Sensitivity
Repeat adjusting L9, L10, L6, and L5 to make the frequencies at highest sensitivity.
