Kenwood TK-885 Service Manual

Also see for TK-885: Instruction manual Service manual

Contents

20TK-885 DESCRIPTION OF COMPONENTSRef. No. Use / Function Operation / ConditionQ27 SB switch Active while Q28 is onQ28 SB SW control Active while Q30 is on, and Q31 is offQ29 H/L switch Active while RF power is HighQ30 SB SW control Active while power switch is onQ31 SB SW control Active while power supply voltageis more than 20VQ32 DET mute Active while TXQ201 RF amp Low noise amplifierQ202 RF amp Power module predriveQ203 Pre IF amp 44.85MHzQ204,205 RF amp Power module driveQ300 Buffer amp PLLQ301,302 Active filterQ401 Short protection Power module protectionQ402,403 W/N switch No functionD1~6 ProtectionD7 HOR protectionD8,9 ProtectionD11 AF muteD12~14 ProtectionD15 HT switchD16 Reverse protectionD17 ProtectionD20 Reverse protection IGND21 Protection 5V (IGN)D22,23 W/N switch No functionD24 Over currentprotectionD26 Reverse protectionD27 Power detectionD28 ProtectionD30 Power detectionD31 Reverse protectionD32 Surge absorption BD34 Protection Active while power supply voltageis more than 20VD35 Charge DEOD37 Reverse protectionD200 Large input protectionD203~206 BPF tuneD207 Usable temperaturerangeD209 ANT swtich Active while TXD210,211 ANT switchD212~215 BPF tuneControl Unit (X57-6152-70) (B/2)Ref. No. Use / Function Operation / ConditionIC501 LPF, amplification LSDIC502 Amplification AF, HSDIC503 Reference voltage/ ASQBuffer ampRef. No. Use / Function Operation / ConditionIC504 Audio processor Compander, MIC amplifier, ALC,Modem, AF filter, IDCIC506 Analog switch MO, DEO, EMG, MI switchIC507 DTMF decoder No functionIC508 Shift register LR, LG, KBLC, MM1, T/R, KEY,BSFT, PA2 outputIC509 Reset Low voltage output when powering upIC510 Flash ROMIC511 CPUIC512 EEPROMIC513 5V AVR 5C (Control unit)IC710 Buffer amp HSDIC711 Buffer amp MICQ501 MIC mute Active while MM is “H” and MM1 is “H”Q502 AF mute Active while KEY is “H”Q503 Noise ampQ507 Inverter PA2 H/L switchQ508 LED switch (Green) Active while LG is “H”, active while RXQ509 LED switch (Red) Active while LR is “H”, active while TXQ510 Clock switch shift Clock shift is on while BSFT is “H”Q511 FSW swtich Foot switch is on while FSW is “L”Q512,513 Key backlight switch Active while KBLC is “H”Q515 Keybacklight switchD501 Surge absorption BLCD502 Over current PSBprotectionD503 Surge absorption CMD504 Surge absorption PTT/TXDD505 Surge absorption HOOK/RXDD507 MIC mute MM/MM1D508 Limiter MICD509 Limiter ASQD510 Reverse current C575 chargeprotectionD511 BUSY/TX LED Lights green while busy, red while TXD512~517 Key backlight Active while KBLC is “H”D518 Current regulation Key backlightD520 Discharge Speed upVCO Unit (X58-4722-70)Ref. No. Use / Function Operation / ConditionQ101 Oscillator RXQ102 Inverter Active while ST is “H”, active while TXQ103 Oscillator TXQ104 TX/RX switch Active while ST is “H”, active while TXQ105 TX/RX switch Active while Q102 is offQ106 Buffer ampD101 RX VCOD102 TX VCOD103 RX VCOD104 TX VCOD105 Modulation