Kenwood NX-720 Service Manual page 112

AJ
NX-720
THP1
50C
/T_R
33C
C37 C43
FIN
8p
100p
L4
10n
PLL f-in BPF Tune
R34
1.8k
RX VCO
RX VCO Assist Tune
Frequency Control
C44
R37 L6
10u
0
100p
R35
0
TX VCO
Frequency Control
TX VCO Assist Tune
L7 C45
R38
10u
0
330p
R36
0 D11,12
TX VCO
Assist Tune
150C
B-BUS
CN205 CN204
XF1 49.95MHz
L71-0678-05
R394 L301
180 150n
150C
SP+
SP-
MIC
ME
B-BUS
POWER
112
X57-823 8/10
AK
SCHEMATIC DIAGRAM / 原理图
R50
56
R:4.61V
T:4.62V
C50 C60
7p 4p
Q5
2SC5108(Y)F
PLL f-in BPF Tune
RX VCO
Q6
MCH3914(7)-H
RX VCO
D7
C55
39p
1SV282-F
D9,10
TX VCO
RX VCO Assist Tune
Q7
MCH3914(7)-H
TX VCO
D8
C54
180p
1SV282-F
FM
Modulation
. .
R44
C51
R52
1u 27k
470k
L19
Ripple Filter
Q4
2SC5383-T111
Speed up
R:4.76V
T:4.74V
CN203
CN206
4.77V
L317 L319 L203
C360
270n
390n 180n
0.01u
R203
680
AL
R:2.9V
Buffer AMP
T:2.82V
(PLL Fin)
R:2.7V
T:2.49V
R:4.00V
T:0V
R58 R:3.79V
T:3.76V
22
R61
R:0.72V
R:0.86V
T:0.68V
T:0V
150k
C77
0.5p
Q10
2SC5108(Y)F
Buffer AMP
R:0V
T:3.9V
R57
22
R:0V
T:1.08V
C76
0.5p
R:0V
T:4.02V
T/R VCO Switch
R:4.08V
T:0V
Q9
Q8
SSM3J15FS
EM6M1
4 3
5 2
6 1
T/R VCO
Switch
R:3.28V
T:0V
R56
0
R:4.09V
T:4.06V
L204 L205
33n
39n
C211 C213
R204
4.7k
3p
6p
BPF
.
C216 R223
Q201
3SK318
.
0
1000p
C215
RX 1st Mixer
R230
1000p
0
150C
AM AN
TX-RX UNIT (X57-8230-11)
R80 R86
0 0
R81 R87
0 0
R82 R88
0 0
R:3.56V
Buffer AMP
T:3.76V
D17
R:1.56V Q11
RKS151KJ
T:1.35V C89
2SC5108(Y)F
C81 C84
15p
22p 15p
R:1.21V
T:1.97V
L26
. .
C218 L220
2p 270n
D202-207
RX BPF Tune
f L:2.28V
fC:4.96V
fH:8.93V
.
R257
. 150C
100k
IC201
13.94V
BD7542FVM
1 oUT1
VDD 8
2
+ 7
-
3
+ 6
-
4 VSS
5
DC AMP(BPF)
.
.
0.1u
C239
C240 1u
R83
0
THP1
R:2.01V
T:2.48V
D16,17
T/R Switch
R:2.75V
T:0V
B-BUS
SP+
SP-
MIC
ME
B-BUS
POWER