Kenwood FM Transceiver TK-481 Service Manual

Also see for FM Transceiver TK-481: User manual Instruction manual Specifications Instruction manual Service manual

23TK-480/481DESCRIPTION OF COMPONENTSDISPLAY UNIT (X54-3210-XX)Ref. No. Use/ Function Operation/ConditionIC300 IC Audio power amplifierIC301 IC Counter / Key scanQ300 FET DC switch / INT MIC on/offQ301 FET DC switchQ302 Transistor DC switch / LED (Red) driverQ303 Transistor DC switch / LED (Green) driverQ304 Transistor DC switchQ305 Transistor Current driver / Audio amp AVRQ306 Transistor DC switchQ307 Transistor Current driver / LCD back light LED AVRQ308 FET DC switch / SP INT/EXTQ309 Transistor Temperature compensationQ310 FET Mute switchD300 Zener diode Surge absorptionD301 LED LED / Red, GreenD302 Diode Quick discharge / AF muteD303 Zener diode Voltage referenceD304 Diode Voltage referenceD305~310 LED LCD back lightD315~318 Diode Reverse current preventionD319~321 Zener diode Surge absorptionRef. No. Use/ Function Operation/ConditionIC15 IC Microprocessor / 16-bit+1M flashIC16 IC EEPROMIC17 IC AND gateIC18,19 IC Shift register / Output expanderIC21 IC Comparator (APC)IC23 IC Active filter / For HSDoutIC30 IC Power moduleQ1 FET DC switch / 5RQ2 Transistor DC switch / 5TQ3 Transistor Ripple filter / 5CVQ4 Transistor TX/RX switchQ5 Transistor IF amplifierQ6 FET MixerQ7 FET Mute switch / MIC line muteQ8 Transistor RF amplifierQ9 FET RF amplifierQ10 Transistor Buffer amplifierQ11,12 Transistor RF amplifier / TX driverQ13 FET DC switchQ14,15 Transistor DC switchQ16 Transistor AF mute switchQ17 Transistor RF amplifierQ18 FET DC switchQ19 Transistor Noise amplifier / SquelchQ20 Transistor SwitchQ21 FET AF mute switchQ22 FET DC switchQ23 FET Mute switchD1 Diode Reverse protectionD2 Diode Overload protectionD3 Diode Noise detectionD4,5 Diode TX/RX switchD6 Diode Overload protectionD7 Diode ANT switchD8 Diode Reverse current preventionD9,10 Diode ANT switchD11 Diode Voltage clampD12 Diode DC switchD17,18 Diode Surge absorptionTX-RX UNIT (X57-5630-XX)Ref. No. Use/ Function Operation/ConditionIC1 IC Buffer amplifierIC2 IC Voltage detector / ResetIC3 IC Summing amplifierIC4 IC D/A converter (Adjustment)IC5 IC Voltage regulator / 5MIC6 IC Voltage regulator / 5VIC7 IC Voltage regulator / 5CIC8 IC Buffer amplifierIC9 IC FM IF systemIC10 IC Active filter / For LSDinIC11 IC PLL systemIC12 IC Audio processorIC13 IC DTMF decoderIC14 IC VCO system