Kenwood TH-K20A, Service Manual

Page: 20 / 40

TH-K20A/K20E
20
ADJUSTMENT
Common Section
Item Condition
Measurement Adjustment
Specifi cations / Remarks
Test-
equipment
Unit Terminal Unit Parts Method
1. Setting 1) BATT terminal voltage: 7.5V
2) SSG standard modulation
[Wide]
MOD: 1kHz, DEV: 3kHz
[Narrow]
MOD: 1kHz, DEV: 1.5kHz
2. VCO Lock
Voltage
1) Adj item: High Power
meter TX-RX ANT
(CV)
MCP-
5T 4.0V
[V] indicator on the
PC window shows
VCO lock voltage.
Change the adjust-
ment value to get
VCO lock voltage
within the limit of the
specifi ed voltage.
±0.1V
Press [Apply] button to store
the adjustment value.
Note:
• Press [Apply] button to store the adjustment value. (For single adjustment point)
• Press [Apply All] button to store the adjustment value after all adjustment points have been adjusted. (For 3 adjustment point)
Transmitter Section
Item Condition
Measurement Adjustment
Specifi cations / Remarks
Test-
equipment
Unit Terminal Unit Parts Method
1. Frequency 1) Tuning point: High
Press [Transmit] button. f. counter TX-RX ANT MCP-
5T 173.900MHz ±50Hz
2. High
Transmit
Power
and
Protective
Current
1) Tuning point: Low, Center,
High (3 points)
BATT terminal voltage: 7.5V
Press [Transmit] button.
Power
meter
Ammeter MCP-
5T 5.5W ±0.1W
2.0A or less
3. Low
Transmit
Power 1) Tuning point: Low, Center,
High (3 points)
BATT terminal voltage: 7.5V
Press [Transmit] button.
1.0W ±0.1W
1.0A or less
4. Mid
Transmit
Power 1) Tuning point: Low, Center,
High (3 points)
BATT terminal voltage: 7.5V
Press [Transmit] button.
2.0W ±0.1W
1.5A or less
5. DCS
Balance
[Wide] 1) Tuning point: Low, Center,
High (3 points)
(Signaling Square Wave)
Deviation meter fi lter
LPF: 3kHz
HPF: OFF
Press [Transmit] button.
Power
meter
Deviation
meter
Oscilloscope
AG
AF VM
TX-RX ANT
SP/MIC
connector
MCP-
5T Make the modulation
wave into square
waves.
6. Maximum
Deviation
[Wide] 1) Tuning point: Center, Low,
High (3 points)
AG: 1kHz/150mV
Deviation meter fi lter
LPF: 15kHz
HPF: OFF
Press [Transmit] button.
4.0kHz
(According to
the , –) ±100Hz