Description Of Components - Kenwood FM Transceiver TK-481 Service Manual

DISPLAY UNIT (X54-3210-XX)
Ref. No. Use/ Function
IC300 IC Audio power amplifier
IC301 IC Counter
Q300 FET DC switch
Q301 FET DC switch
Q302 Transistor DC switch
Q303 Transistor DC switch
Q304 Transistor DC switch
Q305 Transistor Current driver / Audio amp AVR
Q306 Transistor DC switch
Q307 Transistor Current driver / LCD back light LED AVR
Q308 FET DC switch
Q309 Transistor Temperature compensation
Q310 FET Mute switch
D300 Zener diode Surge absorption
D301 LED LED
D302 Diode Quick discharge
D303 Zener diode Voltage reference
D304 Diode Voltage reference
D305~310 LED LCD back light
D315~318 Diode Reverse current prevention
D319~321 Zener diode Surge absorption
TX-RX UNIT (X57-5630-XX)
Ref. No. Use/ Function
IC1 IC Buffer amplifier
IC2 IC Voltage detector
IC3 IC Summing amplifier
IC4 IC D/A converter (Adjustment)
IC5 IC Voltage regulator
IC6 IC Voltage regulator
IC7 IC Voltage regulator
IC8 IC Buffer amplifier
IC9 IC FM IF system
IC10 IC Active filter
IC11 IC PLL system
IC12 IC Audio processor
IC13 IC DTMF decoder
IC14 IC VCO system

DESCRIPTION OF COMPONENTS

Operation/Condition
/ Key scan
/ INT MIC on/off
/ LED (Red) driver
/ LED (Green) driver
/ SP INT/EXT
/ Red, Green
/ AF mute
Operation/Condition
/ Reset
/ 5M
/ 5V
/ 5C
/ For LSDin
Ref. No. Use/ Function
IC15 IC Microprocessor
IC16 IC EEPROM
IC17 IC AND gate
IC18,19 IC Shift register
IC21 IC Comparator (APC)
IC23 IC Active filter
IC30 IC Power module
Q1 FET DC switch
Q2 Transistor DC switch
Q3 Transistor Ripple filter
Q4 Transistor TX/RX switch
Q5 Transistor IF amplifier
Q6 FET Mixer
Q7 FET Mute switch
Q8 Transistor RF amplifier
Q9 FET RF amplifier
Q10 Transistor Buffer amplifier
Q11,12 Transistor RF amplifier
Q13 FET DC switch
Q14,15 Transistor DC switch
Q16 Transistor AF mute switch
Q17 Transistor RF amplifier
Q18 FET DC switch
Q19 Transistor Noise amplifier
Q20 Transistor Switch
Q21 FET AF mute switch
Q22 FET DC switch
Q23 FET Mute switch
D1 Diode Reverse protection
D2 Diode Overload protection
D3 Diode Noise detection
D4,5 Diode TX/RX switch
D6 Diode Overload protection
D7 Diode ANT switch
D8 Diode Reverse current prevention
D9,10 Diode ANT switch
D11 Diode Voltage clamp
D12 Diode DC switch
D17,18 Diode Surge absorption
TK-480/481
Operation/Condition
/ 16-bit+1M flash
/ Output expander
/ For HSDout
/ 5R
/ 5T
/ 5CV
/ MIC line mute
/ TX driver
/ Squelch
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