Components Description - Kenwood TK-80 Service Manual

TK-80
FINAL UNIT (X45-3520-21)
Ref. No. Use / Function
IC1 Comparator
IC2 Regulator
IC3 Regulator
IC4 Band data decoder
Q1 Pre-drive amplifier
Q2,3 Drive amplifier
Q4 Final bias supply
Q5,6 Final amplifier
Q7 Relay drive
Q8 Switching transistor
Q9,10 Fan motor drive
Q12 Switching transistor
Q13 Signal switch
Q14~21 Signal switch
D1 Temperature
compensation
D2 Temperature
compensation
D3,4 Temperature
compensation
D5 Protection diode
D6 Zener diode
D7 Relay surge
absorption
D8 Protection diode
D9 Switching
D10,11 RF detection
D12 Relay surge
absorption
D13 Spike surge
absorption
D14 Switching
D15 Surge voltage
absorption
26

COMPONENTS DESCRIPTION

Operation / Condition
Fan control
14V→5V
14V→8V
Serial to parallel conversion
HF band wide band amplification
HF band push-pull wide band
amplification
Final temperature compensation
HF band push-pull wide band
amplification
The relay is energized when
power is turned on
On when over voltage occurs
Runs the fan during transmission
or when the temperature rises
Off when the control circuit is
troubled
Transmit/Receive changeover relay drive
Low pass filter changeover relay drive
Pre-drive temperature detection
Drive temperature detection
Final temperature detection
Reverse power connection
Over voltage detection
Relay counter voltage bypass
Fan counter voltage bypass
OR circuit
SWR power detection
Transmit/Receive changeover relay
Surge absorber
OR circuit
14V line
Ref. No. Use / Function
D701~706 Relay surge
absorption
CONTROL UNIT (X53-3570-21)
Ref. No. Use / Function
IC1,2 Inverter
IC3 Reset
IC4 Regulator
IC5 CPU
IC6 EEPROM
IC7 I/O port
IC8 Buffer
Q1,2 Signal switch
Q3,4 Signal switch
Q5,6 Signal switch
Q7 Signal switch
D1 Switching (reverse
flow prevention)
D2 Reverse flow
prevention
D3 Switching
D4 Zener diode
D5,6 Reverse flow
prevention
D7,10~13 Switching
D14 Zener diode
D15 Switching
D16~18 Reverse flow
prevention
TX-RX UNIT (X57-4660-21)
Ref. No. Use / Function
IC1 Switching
IC2 Amplifier
IC3 Switching
IC4 Balanced
modulation
IC6 Electrical volume
Operation / Condition
LPF relay counter voltage bypass
Operation / Condition
Encoder shape wave
Constant voltage 6V output
Microprocessor
4k bits
8 bit x 3, 24 ports
Buffer of serial interface
Backup judgment
On during AT tune
On during AT through
Off in AF mute
CPU power supply OR circuit
Standby switch OR circuit
Backup detection (voltage shift)
Destination selection
AF mute detection (voltage shift)
Destination selection
Key matrix judgment
Operation / Condition
Analog switch
S-meter level amplification
Analog switch
SSB AM modulation