Kenwood TK-885, Service Manual

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TK-885
TX-RX Unit (X57-6373-01) (A/2)
Ref. No. Use / Function Operation / Condition
IC1 DC amp FC, TCXO control
IC2 DET amp External DEO, internal DEO
IC3 Amp/Summing amp DI / DI and MO addtion
IC4 Analog switch DI switch
IC5 A/D converter PC, TV, FC, AFO, BEEP, TO, MO
control
IC6 DC amp PC, TV
IC7 Shift register HNC, H/L, TOF, CODE3, CODE4,
PA, W/N control
IC8 Shift register AM, LOK, STR, DM, OPT, CODE1,
CODE2 control
IC9 5V AVR External 5C
IC10 AF power amp
IC11 FM IF DET Quadrature detector, 2nd mixer,
OSC, IF amplifier, RSSI
IC12 5V AVR 5C
IC13 9V AVR 9C
IC14 8V AVR 8C
IC15 Flip-flop Power on/off control
IC200 Mixer DBM
IC300 PLL Reference 16.8MHz.
PLL lock : LD “H”
IC400 Power module RF power 25W
IC401 Short protection
Q1 DC switch When PTT on CN1 is “H”,
DI on CN1 is muted
Q2 Ripple filter 8CL
Q4 HOR switch IGN
Q5 HOR SW control IGN
Q6 HOR SW control Active while HNC is “H”
Q7 Buffer amp HT
Q8 AF mute Active while AM1 is ”H”
Q9 AF mute Active while power switch is off
Q10 8R SW control Active while T/R is “H”
Q11 8R switch Active while Q10 is active
Q12 8T switch Active while Q13 is active
Q13 8T SW control Active while KEY is “H”
Q15 IF amp 44.85MHz
Q16 AF switch No function
Q17 PC switch Active while TX
Q18 DET mute Active while KEY is “H”
Q19 APC APC driver
Q20 APC APC predriver
Q21 APC control
Q22 TOF switch Active while TOF is “H”
Q23 W/N switch Active while Narrow.
Q24 W/N switch Active while Wide.
Q25 TOF switch Active while Q22 is on
Q26 Inverter Active while power switch is “L”
Q27 SB switch Active while Q28 is on
Q28 SB SW control Active while Q30 is on, and Q31 is off
DESCRIPTION OF COMPONENTS /