Kenwood 144MHz FM TRANSCEIVER K2E Service Manual page 56

U
TH-K2AT/K2E/K2ET
TX-RX UNIT (X57-674X-XX)(A/3)
5T RF SW
+B
D8
TX PATH
RF AMP
HSC277
Q9
2SC5488
D9
R347
100
HSC277
RF SW
2.00V
5R
4.90V
5T
C137
L28
L29 22n
27n 5p
C136
10p
FINAL
+B
APC CIRCUIT
Q13
OPERATION SW
2SK1830
5T
KAPC
TEMP
38.85MHz
1st IF
XF1
R90
L71-0619-05
330 C128
R88
0.01u 330
X57-674X-XX
0-11 TH-K2AT K,K2 B30-2205-05
2-71 TH-K2E E
2-72 TH-K2ET E3 B30-2205-05
5R
0-21 TH-K2AT M,M2 B30-2205-05
X57-674X-XX R230
0-11 TH-K2AT K,K2 220
2-71 TH-K2E E NO
2-72 TH-K2ET E3 220
0-21 TH-K2AT M,M2 220
BPF/APC
Reference voltage value are measured when the power supply voltage is 13.8V(DC IN).
X57-674 5/5
V
T:4.23V T:4.85V
R:0V R:0V
C65 18p
DRIVE
1.40V
AMP
Q10
2SC4926YD
Q15
2SC4617(R)
Q10 OPERATION SW
Q12
POWER 2SK3476
AMP
T:0V
R:0V
CN10
Q12 GATE
VOLTAGE SW
Q58
2SK1830
2.29V
(HIGH POWER)
R76 150k (D)
APC
R74
C108
100k DIFFERENTIAL
AMP
100p
(D)
IC2
NJM2904V
1
AOUT
2
A-IN
3
A+IN
R75
4
GND
100k
(D)
R79
C110
150k (D)
C356
2.68V
L27 1st MIXER
4.71V
680n
Q16
3SK318 2.42V
R341 C142
0
1000p
D44 D47 D60 D62
B30-2205-05 NO MA2S111 MA2S111
NO NO MA2S111 MA2S111
B30-2205-05 NO MA2S111
B30-2205-05 NO NO MA2S111
R257 R258 R259 R261 R264 R344
56k 680 680k 47k NO 100k
NO 0 0 NO 0 NO
NO 0 0 NO 0 NO
NO 0 0 NO 0 NO
W
SCHEMATIC DIAGRAM
C68 C326
R271
1.30V
18p 12 1000p
L12
10n
R34
3.3k
VOLTAGE
DROP
5T
VGG
12.29V
L17 C89
18.5n 1000p
ANTENNA SW
D10
XB15A709
R61 220
R62 220
5T
8 APC OUTPUT SW
V+
DC SW
7
BOUT
R81 390k
6
B-IN
5 C112 1000p
B+IN
Q14
R83 56k RN4902
APC
1000p
0.01u
D14
REVERSE CURRENT PREVENTION
D18,19
RX BPF TUNING
4.66V
C500
C501
1.5p 1.5p
R102
0
(B) (B)
2SK1215(E)
RX 1st AMP
5R
D63 Q59 C320 C321 C350 C510 C511
2SK1830 8200p 8200p 0.1u NO NO
NO NO NO NO NO 100p 470p
NO NO NO NO NO 100p 470p
NO NO NO NO NO NO
CN17
NO
E23-1081-05
E23-1081-05
NO
Note : The components marked with a
X Y
12.46V
C75
L55 C329
10n
1000p 56p
Q11
2SK2596
DRIVE
AMP
VDD
L20 L21 L22
9T 9T
7T
C94
1000p C96 12p C98 8p C100 7p
(G) (B) (B)
D17
OVER INPUT
PROTECTION
D12,13 HSM88AS
ANTENNA SW
VGG
TEMP
R85 560 COMPENSATION
APC OUTPUT
VOLTAGE LIMITTER
KAPC
D20,21
RX BPF TUNING
0.27V
C159 C502
2p 3p
R345
0
(B) (B)
Q17
C162
R291
47p
(G)
C512 C514 C515 C516 C517
NO NO NO NO NO
470p 470p 470p 470p 470p
470p 470p 470p 470p 470p
NO NO NO NO NO
dot ( ) are parts of layer1.
1
L15
6.8n
2
ANT
3
4
5
R290
0 0
6
7