Kenwood NX-800 Service Manual page 140

AY
NX-800
2
3.28V BUFFER AMP
(2nd IF DET)
1.65V
C710
0.01u
1.31V 1.31V
MIC
1.65V
R850
MOD
0
1
/SCSW
450K
PLD
MIC SUM1
1
13
9 SUM AMP
(AI/TONE/MI1/MI2)
/(MOD/DI)
MOD SUM
9 13
1
9
13
140
X57-775 (A/2) 11/16
AZ
SCHEMATIC DIAGRAM /
2nd IF BUFF
R : 0V 1.63V
T : 1.63V
MIC AA
C707 R716
0.1u 0
R725
R722 68k
68k
C732
1.63V
0.01u
IC702
TC75W51FK(F)
1.63V
5
R714
VSS
R705 100k
6
100k
1.63V
7
8
VDD
3.28V
LPF (MOD)
C720
0.1u
MOD SMF
D704,705
Q704,705
AF DETECTOR
(LIMIT) LIMIT
Q704
D704
2SC4738(GR)F
RB706F-40
R784
150k
D705
RB706F-40
R787
270k
Q705
2SA1832(GR)F
R779
1.62V 470k 1.62V
C764 R786 C773
22p 39k 0.1u
33A-2
3.28V
IC709
TC75W51FK(F)
R789
1.63V
0
R773 680k
1.63V
C757 15p
R774 470k
C815 10u
C816 10u
11
BA
原理图
2
3.28V
C729
0.1u
IC706
TC75W51FK(F)
1.63V
1 8
VDD
7
2
3 6 R748 R753
4 5
0
1.63V
VSS
LPF/SUM AMP MIC SUM2
4
1.62V
3
R739
2
0
1.62V
R731
1
0
33A_2
MUTE (MI2)
Q707
MUTE (MI1) 2SJ243-A
Q706
2SJ243-A
R796 C782 C787
10k 0.1u 10u
3.25V
R : 3.31V
T : 0V
R798 C784
1
680k 0.1u
R797 C783 R806
2
330k 0.1u 5.6k
6
1
9
13
BB BC
TX-RX UNIT (X57-7752-71) (A/2)
C742 R766 C748
DTI
56k 0.1u 100k 0.1u
C744
0.1
IC708
3.28V
TC7W53FK(F)
1 8
R767 C762
CoMMoN VCC
47k 0.1u
2 7
INH CH0 TXI
3
R768 C763
6
VEE
CH1 TXO
4
47k 0.1u
GND 5
A
AF SW
(TXO/TXI)
SCSW(MIC)
C794
10u
3.26V
C795
10u
11
10
2
OPT10
11
13
VREF
11
10
13
PLD
1
9
13
MI2
MI1
ME