Kenwood TK-290 Service Manual page 26

TK-290
SEMICONDUCTOR DATA / DESCRIPTION OF COMPONENTS
6. VCO System : KCH40 (TX-RX Unit IC10)
6-1. Circuit diagram
R6
L4
MOD 1
–V 2
GND 3
L1
4
CV
Control Unit (X53-3780-XX) -10 : K -11 : K2
Ref. No. Use / Function
IC1 Audio power amplifier
IC2 Decimal counter
IC3 MIC noise canceling circuit
IC4 Option board (MAND)
control switch
IC5 Option board (OPPTT)
control switch
IC6 Option board (TCONT)
control switch
IC101 LCD driver
IC501 RF power amplifier
Q5 AF AMP switch
Q6 AVR
Q7 Int. audio mute switch
Q8 Audio mute switch
signal off
26
R5
C23
D9
Q2
C8
D4
C12
C22
D7
Q1
C1
D2
C5
Operation / Condition
0.5W/16 , BTL method
AND circuit
MAND : "H", OUT : "H"
when Q8 port is "H"
AND circuit
OPPTT : "H", OUT : "H"
when Q9 port is "H"
AND circuit
MAND : "H", OUT : "H"
when Q9 port is "H"
AF AMP SW "H" : on
AF AMP switch power
supply
INT. AFC "H" : INT. SP
audio signal on
MUTE "L" : RX audio
Q5
Q4
L8
R9
+
8
4C
R7
7 TX/RX
6 GND
5
Fo
C16
Q3
Ref. No. Use / Function
Q14 N/C switch
Q15 Ext. audio mute switch
D2 AVR
D6~9 Key pad backlight
D11 Reverse current prevention
for number key pad
D12,13 Reverse current prevention
for PF key.
D14 Reverse current prevention
for number key pad
D15,16 Reverse current prevention
for PF key.
D17,18 Reverse current prevention
for number key pad
D19,20 Reverse current prevention
for PF key.
D101 Speed up
D102,103 LCD backlight
D104 LED
7. Active DBM : GN2011
(TX-RX Unit IC200)
7-1. Circuit diagram
G1
G2
Operation / Condition
N/C switch "H" : N/C on
EXT AFC "H" : EXT. SP
audio signal on
AF AMP power supply
Red, green
D1
D2
S2
S1