Kenwood TK-780 Service Manual

Also see for TK-780 series: Programming instructions Instruction manual Service manual supplement Instruction manual Service manual

33TK-780Ref. No. Use / Function Operation / ConditionQ24 W/N switch Wide time onQ25 TOF switch Q22 on time onQ26 Inverter Power switch “L” time onQ27 SB switch Q28 on time onQ28 SB SW control Q30 on and Q31 off time onQ29 H/L switch High power time “H”Q30 SB SW control Power on time onQ31 SB SW control DC 20V and over time onQ32 DET mute TX time onQ202 LNAQ203 RF amp TX drive firstQ204 RF amp TX drive lastQ300 Buffer amp PLLQ301,302 Active filterQ401 Short protection IC400 out short time onQ402 W/N switch Wide time offQ403 W/N switch Wide time onD1~6 ProtectionD7 HOR protectionD8,9 ProtectionD11 OR gate AF muteD12~14 ProtectionD15 HT switchD16 Reverse protectionD17 ProtectionD20 Reverse protection IGND21 Protection 5V (IGN)D22,23 W/N CF changeD24 Over currentprotectionD26 Reverse protectionD27 Power detectionD28 ProtectionD30 Power detectionD31 Reverse protectionD32 Surge absorption BD34 Protection DC 20V and over time onD35 Charge DEOD37 Reverse protectionD206~208 BPF tuneD209,210 Usable temperaturerangeD211 ANT swtich TX time onD212,213 ANT switchTX-RX Unit (B/2) : Control SectionRef. No. Use / Function Operation / ConditionIC501 LPF, amplification LSDIC502 Amplification AF, HSDIC503 Base voltage/ ASQBuffer ampIC504 Audio processor Compander, MIC amplifier, ALC,Modem, AF filter, IDCRef. No. Use / Function Operation / ConditionIC506 Analog switch MO, DEO, EMG, MI switchIC507 DTMF decoder DTMF detectionIC508 Shift register LR, LG, KBLC, MM1, T/R, KEY,BSFT, PA2 outputIC509 Reset Power on time “L” outputIC510 Flash ROMIC511 CPUIC512 EEPROMIC513 5V AVR 5C (Control unit)IC710 Buffer amp HSDIC711 Buffer amp MICQ501 MIC mute MM “H” and MM1 “H” time mute onQ502 AF mute KEY “H” time mute onQ503 Noise ampQ507 Inverter PA2 H/L switchQ508 LED switch LG “H” time on, Busy time green onQ509 LED switch LR “H” time on, TX time red onQ510 Clock switch shift BSFT “H” time clock shift onQ511 FSW swtich FSW “L” time foot switch onQ512 Key backlight switch KBLC “H” time onQ513 Key backlight switch KBLC “H” time key backlight onQ515 Key backlight switchD501 Surge absorption BLCD502 Over current PSBprotectionD503 Surge absorption CMD504 Surge absorption PTT/TXDD505 Surge absorption HOOK/RXDD507 OR gate (MIC mute) MM/MM1D508 Limiter MICD509 Limiter ASQD510 Reverse current C575 chargeprotectionD511 BUSY/TX LED Busy time green on, TX time red on(Green/Red)D512~517 Key backlight KBLC “H” time onD518 Current regulation Key backlightD520 Discharge Reset pulseVCO UnitRef. No. Use / Function Operation / ConditionQ101 Inverter TX (ST “H”) time onQ102 Oscillator RXQ103 Oscillator TXQ104 TX/RX switch TX (ST “H”) time onQ105 TX/RX switch Q101 off time onQ106 Buffer ampD101 RX VCOD102 TX VCOD104 RX VCOD107 TX VCOD109 ModulationDESCRIPTION OF COMPONENTS