Kenwood TM-471A Service Manual page 24

TM-471A
PCB Section
Item
1. Setting 1) Power supply voltage
DC Power supply terminal : 13.8V
2. VCO lock 1) CH : TX high
voltage*
2) CH : RX high
3) CH : TX low
4) CH : RX low
3. IF coil 1) CH : RX center (Wide)
2) SSG output : –53dBm (501µV)
Mod : 1kHz
Dev : 3kHz
* Adjustment of TX VCO lock voltage
1. Remove R525, F501, R536 and R822 (all on component side).
2. Remove PCB from chassis.
3. Transmit and check voltage at [CV] point.
Warning : Do not transmit if step "1." is not complete.
4. Adjust of voltage can be done by tuning TC402.
Transmitter Section
Item
1. Frequency 1) CH : TX center
2) Transmit
2. Maximum 1) CH : TX high
power 2) Adjustment HEX value : FF
alignment 3) Transmit
3. High 1) CH : TX low
power CH : TX low'
CH : TX center
CH : TX high'
CH : TX high
2) Transmit
4. Low 1) CH : TX low
power CH : TX low'
CH : TX center
CH : TX high'
CH : TX high
2) Transmit
5. DCS 1) CH : TX low (Wide)
balance CH : TC center (Wide/Narrow)
CH : TX high (Wide)
2) Transmit
24
ADJUSTMENT
Condition
Test equipment
Digital voltmeter
SSG
Digital voltmeter
Condition
Test equipment
Frequency counter
Power meter
Modulation analyzer
or Linear detector
(LPF : 3kHz)
Oscilloscope
Measurement
Terminal Parts
CV TC402
TC401
AFV L301
Measurement
Terminal Parts
ANT Encoder Adjust to center frequency
knob
VR601
Encoder 40W
knob
Adjustment
Specifications/
Method
± 0.2V
5.5V
± 0.2V
5.5V
Check 0.5V or more
3.25~3.35V (DC)
Adjustment
Specifications/
Method
Within ±20Hz
± 1W
43W
± 1.0W
± 1.0W
25W
Adjust the waveform as below
Remarks
Remarks