Kirisun PT4208, Руководство по обслуживанию

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PT4208 Service Manual
15
“High”, and “Highest” respectively. Firstly, click one of the
frequency points, and adjust the RF signal frequency of the
test equipment to be the same with the receiving frequency
of that frequency point, and adjust the signal level to be
-118dBm. Then adjust the frequency of the modulation
signal to be 1kHz and the deviation to be 3kHz. Click
“Begin”, the programming software will adjust the value
automatically. When the value keeps stable, click “OK”, the
adjustment of that frequency point is completed. Then click
the next frequency point to do the adjustment. After all of the
five frequency points are adjusted, use the same method to
adjust the five frequency points of the narrowband. The only
difference is that the frequency of the modulation signal
should be 1kHz, and the deviation should be 1.5kHz.
In the Tuning Mode, double click the “SQL1 On” and
“SQL1 Off” item to enter respectively. Use the same method
stated above to do the adjustment. The only difference is that
the RF signal level for “SQL1 On” should be 123dBm, and
the RF signal level for “SQL1 Off” should be 125dBm.
6.4 Adjustment Description
See Table 6.3, 6.4, and 6.5.
Table 6.3 VCO
Item Test Condition Test
Equipment
Measurement
Terminal
Adjustment
Parts
Requirement Remark
Setting
BATT terminal
voltage: 7.5V
DMM PD
CH: Rx low freq
point
C180 0.7V±0.3V Adjustment
VCO lock
voltage CH: Tx high freq
point
Lower than
4.5V
Observation
Table 6.4 Receiver Section
Item Test Condition Test
Equipment
Measure
ment
Terminal
Adjustment
Parts
Requirement Remark
Audio level
Test freq: Mid freq
point
Antenna input:
RF OUT: -53dBm
(501 μ V)
MOD: 1kHz
DEV: ±3.0kHz
Audio load: 16 Ω
(Turn the
volume knob
clockwise to
the end) Audio
power ＞
0.3W
Internal speaker
power
＞
1.2W
Sensitivity
CH: Mid freq point
CH: Low freq point
CH: High freq point
RF OUT: -119dBm
(0.25 μ V)
MOD: 1kHz
DEV: ±3.0kHz
PC Tuning
Mode
SINAD: 12dB
or higher
CH: Rx center freq
point
Normal
squelch on
after
adjustment
Level 9
RF OUT: -116dBm
SQL On
sensitivity
Level 1
RF OUT: -123dBm
RF signal
generator
Oscilloscope
Audio
frequency
voltmeter
Distortion
meter
/General test
set
Speaker
connector
PC Tuning
Mode
Normal
squelch on
after
adjustment
Table 6.5 Transmitter Section
Item Test condition Test equipment
Measuring
terminal
Adjustment
parts
Requirement Remark
Tx
frequency
Frequency counter
/ General test set
PC Tuning
Mode
Within ±200Hz
DCS
waveform
(balance)
Oscilloscope /
General test set
Antenna
VR1
Smooth and
similar to square
wave