Description Of Components; Vco Unit - Kenwood TK-880 Service Manual

Ref. No. Use / Function
Q27 SB switch
Q28 SB SW control
Q29 H/L switch
Q30 SB SW control
Q31 SB SW control
Q32 DET mute
Q201 RF amp
Q202 RF amp
Q203 Pre IF amp
Q204 RF amp
Q205 RF amp
Q300 Buffer amp
Q301,302 Active filter
Q401 Short protection
Q402 W/N switch
Q403 W/N switch
D1~6 Protection
D7 HOR protection
D8,9 Protection
D11 AF mute
D12~14 Protection
D15 HT switch
D16 Reverse protection
D17 Protection
D20 Reverse protection
D21 Protection
D22,23 W/N CF change
D24 Over current
protection
D26 Reverse protection
D27 Power detection
D28 Protection
D30 Power detection
D31 Reverse protection
D32 Surge absorption
D34 Protection
D35 Charge
D37 Reverse protection
D200 Large input protection
D203~206 BPF tune
D207 Usable temperature
range
D209 ANT swtich
D210,211 ANT switch
D212~215 BPF tune
D902,903 BPF tune
TX-RX Unit (B/2)
Ref. No. Use / Function
IC501 LPF, amplification
IC502 Amplification
IC503 Reference voltage/ ASQ
Buffer amp

DESCRIPTION OF COMPONENTS

Operation / Condition
Q28 on time on
Q30 on and Q31 off time on
High power time "H"
Power on time on
DC 20V and over time on
TX time on
Low noise amplifier
TX drive first
44.85MHz
TX drive
TX drive last
PLL
Wide time off
Wide time on
IGN
5V (IGN)
B
DC 20V and over time on
DEO
E version
E version
TX time on
E version
E3 version
Operation / Condition
LSD
AF, HSD
Ref. No. Use / Function
IC504 Audio processor
IC506 Analog switch
IC507 DTMF decoder
IC508 Shift register
IC509 Reset
IC510 Flash ROM
IC511 CPU
IC512 EEPROM
IC513 5V AVR
IC710 Buffer amp
IC711 Buffer amp
Q501 MIC mute
Q502 AF mute
Q503 Noise amp
Q507 Inverter
Q508 LED switch
Q509 LED switch
Q510 Clock switch shift BSFT "H" time clock shift on
Q511 FSW swtich
Q512 Key backlight switch KBLC "H" time on
Q513 Key backlight switch KBLC "H" time key backlight on
Q515 Keybacklight switch
D501 Surge absorption
D502 Over current
protection
D503 Surge absorption
D504 Surge absorption
D505 Surge absorption
D507 MIC mute
D508 Limiter
D509 Limiter
D510 Reverse current
protection
D511 BUSY/TX LED
D512~517 Key backlight
D518 Current regulation Key backlight

VCO Unit

Ref. No. Use / Function
Q101 Oscillator
Q102 Inverter
Q103 Oscillator
Q104 TX/RX switch
Q105 TX/RX switch
Q106 Buffer amp
D101 RX VCO
D102 TX VCO
D103 RX VCO
D104 TX VCO
D105 Modulation
TK-880
Operation / Condition
Compander, MIC amplifier, ALC,
Modem, AF filter, IDC
MO, DEO, EMG, MI switch
DTMF detection
LR, LG, KBLC, MM1, T/R, KEY,
BSFT, PA2 output
Power on time "L" output
5C (Control unit)
HSD
MIC
MM "H" and MM1 "H" time mute on
KEY "H" time mute on
PA2 H/L switch
LG "H" time on, Busy time green on
LR "H" time on, TX time red on
FSW "L" time foot switch on
BLC
PSB
CM
PTT/TXD
HOOK/RXD
MM/MM1
MIC
ASQ
C575 charge
Busy time green on, TX time red on
KBLC "H" time on
Operation / Condition
RX
TX (ST "H") time on
TX
TX (ST "H") time on
Q102 off time on
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