Description Of Components - Kenwood TK-890/(B) Service Manual

TK-890/ ( B
General : TK-890/(B)
Ref. No. Use/Function
IC1 Power amplifier
General : TK-890H(B)
Ref. No. Use/Function
IC1 TX drive amplifier
Q6,7 Final amplifier
Final Unit (X45-3570-10) : TK-890H(B)
Ref. No. Use/Function
Q1 DC amplifier
Q2 DC switch
Q3 APC controller
Q4 DC amplifier
Q5 APC comparator
Q8 TX/RX switch
Q9 TX/RX switch
Q10,11 DC switch
D1 Forward wave
rectification
D2 Reflected wave
rectification
D3 Combiner
D4 Surge absorption
D5 Voltage reference
D6 Surge absorption
D7 Protect of reverse
connection
TX-RX Unit (X57-5620-XX) (A/3)
-10 : TK-890/(B) K -11 : TK-890(B) K2
-12 : TK-890(B) K3 -13 : TK-890H(B) K
Ref. No. Use/Function
IC101 FM IC
IC201 Shift register
IC202 AVR
36
) /H ( B )

DESCRIPTION OF COMPONENTS

Operation/Condition
Operation/Condition
Operation/Condition
APC controller
APC controller
APC controller
On when RX
ON when RX
Operation/Condition
1, 2 : Oscillator (73.505MHz)
3 : Mixer output 4 : Vcc
5 : IF input (455kHz)
7 : Noise filter output
8 : Noise filter input
9 : DET output (AF OUT)
10 : Quad input
12 : RSSI output
16 : Input (73.05MHz)
Input : 8V Output : 5V
Ref. No. Use/Function
IC203 AVR
IC301 PLL IC
Q101 1st amplifier
Q102 IF amplifier
Q103,104 Mix local amplifier
Q105 DC switch
Q106 DC switch
Q107 IF amplifier
Q108 DC switch
Q109 SQL amplifier
Q201 TX pre-drive amplifier
Q202 8T switch
Q203 8T switch
Q204,205 TX pre-drive amplifier
Q206 8R switch
Q207 8R switch
Q301 Ripple filter
Q302 Ripple filter
Q303,304 Loop filter
Q305 OSC
Q306 OSC
Q307 OSC
Q308 DC switch
Q309 DC switch
Q310,311 DC switch
Q312 DC switch
Q313 Buffer amplifier
Q314,315 Amplifier
D102~105 IF switch
D107 Noise detector
D108 DC switch
D201 TX pre-drive bias
D301 Frequency controller
D302 Frequency controller
D303 Frequency controller
D304 Frequency controller
D305 Frequency controller
D306 Frequency controller
D307 Modulator
D308 RF switch
A101 DBM
Operation/Condition
Input : SB Output : 9V
1 : CP 2 : DT 3 : EP
4 : Vss 5 : Fin 7 : Vcc
8 : REFin (16.8MHz)
14 : Charge pump output
18 : UL ("H" when lock)
20 : VDD (5V)
RX frequency
73.05MHz
(RX frequency – 73.05)MHz
ON when wide
On when narrow
73.05MHz
On when wide
(Noise amplifier)
8V when TX
On when TX
On when RX
8V when RX
8CL
9CL
TX-VCO
RX low-VCO
RX high-VCO
On when TX
On when RX low
On when RX high
Off when RX low or RX high
Wide/Narrow
On when TX
TX-VCO
RX low-VCO
RX high-VCO
TX-VCO
RX low-VCO
RX high-VCO
TX/RX