Kenwood TK-7160 Service Manual page 32

TK-7160
Item
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. DQT 1) CH : TX low (Wide)
balance CH : TC center (Wide/Narrow)
CH : TX high (Wide)
2) Transmit
6. MAX 1) CH : TX low (Wide)
balance CH : TC center (Wide/Narrow)
CH : TX high (Wide)
2) AG : 1kHz/50mV
3) Transmit
7. MIC 1) CH : TX center (Wide/Narrow)
sensitivity 2) AG : 1kHz/5mV
3) Transmit
8. DQT 1) CH : TX center (Wide/Narrow)
deviation 2) Transmit
9. QT 1) CH : TX center (Wide/Narrow)
deviation 2) Transmit
10. DTMF/MSK 1) CH : TX center (Wide/Narrow)
deviation 2) Transmit
11. Single tone 1) CH : TX center (Wide/Narrow)
deviation 2) Transmit
If normal power is not obtained, please follow the
step below
Open the shielding cover (upper), and screw 3 locations
around ANT pin.
1. Switch off the transceiver.
Impedance of Final FET (Q504) and Drive FET (Q503) can
be measured easily using DVM Ω mode.
Normal condition – Gate : 20kΩ~50kΩ, Drain : 1MΩ~2MΩ
The above impedance values are rough estimations.
2. Switch on the transceiver. Check the voltage at F501 out-
put point.
The voltage is around 13.6V in receiving condition. The
voltage will be 12.6V~ in transmitting condition. If found
0V at this point then F501 is broken.
3. Remove R517.
32
ADJUSTMENT
Condition
Test equipment
Power meter
Modulation analyzer
or Linear detector
(LPF : 3kHz)
Oscilloscope
Modulation analyzer ANT
or Linear detector
(LPF : 15kHz)
Oscilloscope
AG
AF V.M
Modulation analyzer
or Linear detector
(LPF : 3kHz)
Oscilloscope
LPF : 15kHz
Measurement
Terminal Parts
ANT PC key
PC key
MIC
4. Connect 50Ω load at the ANT location.
Transmit and check current drain at High power mode.
If the current drain is less than 1A, then Final FET is bro-
ken.
If the current drain is less than 5.0A, short the Drive FET
gate to ground, and check the current drain.
If the current drain is not 0.1A less than the original value,
then the Drive FET is broken.
5. Check input power level at Drive FET gate location.
Connect the wire to [RF] location.
Transmit and check for power to be within the range of
0.3W~0.6W.
If power found is less than 0.3W, check the circuit before
the Drive FET.
Adjustment
Specifications/
Method
± 1.0W
25W
± 1.0W
5W
Adjust the waveform as below
± 4.0kHz (Wide) ± 50Hz
± 2.0kHz (Narrow)
According to the large +, –
± 3kHz± 0.2kHz
Check
(Wide)
± 1.5kHz± 0.1kHz
(Narrow)
± 0.75kHz (Wide) ± 0.05kHz
± 0.35kHz (Narrow)
± 0.75kHz (Wide) ± 0.05kHz
± 0.35kHz (Narrow)
± 3.0kHz (Wide) ± 0.2kHz
± 1.5kHz (Narrow)
Remarks