Kenwood TH-K20A Service Manual page 29

P
TX-RX UNIT (X57-821X-XX)
DRIVE
Q102
RFM01U7P
RXLO
Hi:1.49V
Mid:1.28V
Lo:1.21V
Hi:3.25V
Mid:2.78V
Lo:2.63V
THERM
C101
22p
5T
CURRENT
VDCSW
TCXO OUT
+B
R232
0
POWC
BPF
RXLO
5R
R324
560
LTA023JEBFS8
5R
W/N
RSSI
5T
SQL
Note : The components marked with a dot (
Q
SCHEMATIC DIAGRAM
FINAL
Q103
RD07MUS2BT112
C113
R116
56p 0
Hi:1.48V
Mid:1.27V
Lo:1.21V
Temp compensation
R103
R: 0V
T:1.09V 2.2k
C102 R101
Q101
2SC4926YD
1000p 18
PRI DRIVE
R:0V
T:0.61V
R: 0V
T:4.91V
C272 C273
C248
3p
1p 1p
D200,201,204
BPF TUNING
L72-1042-05
CF200 450kHz
R252 R253
4.7k 4.7k
C206
C215
270p
0.01u
C207
270p
FM IF
SYSTEM
R249
R204 3.3k
1k
R205 2.2k C209
47p
L79-1474-05
CD200
TH200
NCP18WM474J0S
R210
-t
68k
Q200
W/N SW
W/N
R:4.88V
RSSI
T: 1.59V
W:0V
N:5.01V
SQL
•
) are parts of layer 1.
R
TH-K20A/K20E
L113 L114 L115
3T 6T
5T
C107 L104
33n
1000p
R: 0V
T:4.32V
CURRENT
R120
POWC
1.8k
VDCSW
R:4.98V
T: 0V
7.5V
Q204 R:3.85V
RF AMP
R236 3SK318 T: 1.26V
82
R:4.88V
T: 1.59V
BPF
TCXO OUT
R:4.68V
T: 1.53V
DOUBLER
R214
R:0.61V
C218 330k
T: 0.59V
5p
Q201
R218
1k
L71-0669-05
KTC4080E-P
1st IF(38.85MHz)
XF200
R220
R:0.72V
T: 0.71V
680
C217 R216
180k
0.01u
C223
0.01u
Q202
KTC4080E-P
IF AMP
S
D101 L109 L110
9T
HVC131
C138
C136 C140
L107 C134 D102
6T
1000p
HVC131 6p
1000p
D101,102,103,104
R: 0V
ANT SW
T:0.81V
L112 R119
9T 0
R: 0V
T:4.93V
Q104
LTC014EEBFS8
VDC SW
R:3.11V
T: 1.03V
C256
47p
C265
47p
BPF TUNING
L215 L204 C266
2.7n 22n
3p
C230
10p
R:2.68V
T: 0.89V
CN202
MIXER
R221 C228
R226
Q203
3SK318
330 0.01u 0
5R
T
1
ANT
9T
CN2
6p
2
3
4
5
R:2.44V
T: 0V
6
C244
1000p
7
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X57-821 4/4