High end, adjust TC3, to make VCO voltage-controlled
voltage (CV terminal) be 4.2V 0.2V.
Low end, check VCO voltage-controlled voltage (CV terminal)
to be 0.8V.
2 . Transmitting:
In computer debugging mode
Frequency adjustment
Adjusts the transmitting frequency to within +/-100Hz of the
nominal frequency in the computer debugging mode.
High power adjustment
Adjusts the transmitting power to 3.8-4.6W in the computer
debugging mode..
(5 frequency points including Higher, High, Med, Low, lower)
Low power adjustment
Adjust the transmitting power to 0.8-1.5W in the computer
debugging mode..
(5 frequency points including Higher, High, Med, Low, lower)
Max. frequency deviation
Signal source: MOD:1kHz/120mV LPF:15kHz
Adjust the max frequency deviation in the computer debugging
mode.
3.9kHz---4.6kHz (wideband)
3.2kHz---3.9kHz (median band)
between 1.8kHz---2.4kHz (narrowband)
DCTCSS balance
Signal source: LPF: 300Hz
Adjust DCTCSS balance in the computer debugging mode.
Make the transmitting demodulation waveform be flat square
wave.
CTCSS frequency deviation
Signal source: LPF: 300Hz
Adjust CTCSS frequency deviation in the computer debugging
mode.
0.50kHz---0.85kHz (wideband)
0.50kHz ---0.65kHz (median band)
0.25kHz--0.50kHz (narrowband)
The waveform shall be good.
DCTCSS frequency deviation
Signal source:LPF:300Hz
Adjust DCTCSS frequency deviation in the computer debugging
mode.
0.70kHz ---1.10kHz (wideband)
0.60kHz ---0.85kHz (median band)
0.25kHz---0.50kHz (narrowband)
The waveform shall be good.
DTMF TONE FSK 5T/2T frequency deviation
Adjust DTMF, TONE, FSK and 5T/2T frequency deviation in the
computer debugging mode.
3.2---4.0 kHz (wideband)
3.0kHz---3.6kHz (median band)
1.6---2.4kHz (narrowband)
Transmitting low battery warning
Adjust the transmitting low battery warning in the computer
debugging mode.
Set the power supply voltage at 6.8V, and press start
and then end
3)Receiving :
Sensitivity adjustment
Adjust the sensitivity in the computer debugging mode.
Make the sensitivity of all frequency points the highest
(provided the sensitivity is the highest, the bigger computer
debugging data, the better)
Squelch adjustment
Adjust squelch in the computer debugging mode.
1 9-level squelch on
T he signal level output should be -118dBm (wideband)
-117dBm (narrowband)
Automatically records the corresponding squelch level
2 9-level squelch off
signal level output -120dBm(wideband
-119dBm (narrowband)
Automatically records the corresponding squelch level
1-level squelch on
Signal level output -124dBm (wideband)
-123dBm (narrowband)
Automatically records the corresponding squelch level
3 1-level squelch off
Signal level output -126dBm(wideband)
-125dBm (narrowband)
Automatically records the corresponding squelch level
Note: Voltage for the aforesaid tests: 7.5V +/-0.1V in room
temperature
Frequency range: 350MHz400MHz 400MHz470MHz
450MHz520MHz
Recommendation: Equipment in item 6, 7, 8, 10, 11, and 12 can be
replaced by the HP8920 comprehensive test instrument.
6.2 Debugging
1 . VCO:
Receiving:
High end, adjust TC4 to make VCO voltage-controlled
voltage (CV terminal) be 4.2V 0.2V.
Low end, check VCO voltage-controlled voltage (CV terminal)
to be 0.8V.
Transmitting:
Chapter 7 Technical Specifications
7.1 General Specification
Frequency MHz
Modulation
Number of Channels
Channel Spacing
MF
Working Voltage
Working Temperature
Antenna Impetance
Mic Impedance
Battery (Standard)
Dimension (WxHxD)
Weight
136~174MHz 470~512 MHz
400~470MHz 350~390 MHz
16K0F3E/8K0F3E
16
25 kHz W 20 kHz M 12.5 kHz N
1st MF 51.65MHz 2nd MF 450kHz
7.5V +/-0.1V negative grounding
-25 ~ +55
50
2k
Model KB-70B Li-Ion Battery DC 7.4V , 1700mAh
56 mm 102 mm 29 mm
235g With battery and antenna
7.2 Receiver
PT7200 SERVICE MANUAL
11
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