Main-A Unit - Icom IC-756PROIII Service Manual

10-4 MAIN-A UNIT

MAIN-A UNIT (1)
W702
J741 C702 0.1
L701 EXC-ELDR25C
C703 0.1
C704 0.1
C705 0.1
L702 HF50ACC322513-B
L703 HF50ACC322513-B
GND
L704 100µH
to CTRL-A
unit J7
L705 100µH FORV
L706 100µH REFV
L707 100µH ANTS
DRES
W703
GND
R763 220 FSTB
CMDT R761 220 MDAT
CMCK R762 220
J101
from RF-B 2IF
unit J1851
C122
R118 L115
0.1
470 330µH
J771
L716 HF50ACC322513-B
PAT8
L715 100µH PWRS
L714 100µH
L713 100µH
L717 HF50ACC322513-B
L712 HF50ACC322513-B
L711 HF50ACC322513-B 14VA
L710 EXC-ELDR25C
to PA
unit J3
L709 HF50ACC322513-B
L708 100µH
GND
J811
L720 100µH
L719 EXC-ELDR25C
L721 150µH
to RF-B
unit J451
SATV
BLBV
BLAV
SCPL
GND
R3801 220 MDAT
R3802 220
R3803 220 BSTB
J841
GND
UNLC
PSEL
CON2
to PLL
unit J1
CON1
CON0
DRES
PSTB
14V
L271
LS-450 Q272
Q271
2SK882
2SK882
T8V
5V
–8V
ISTA
IKEY R8V
MCK
14V
T8V
–8V
H5V
2IF
8V
14VA
HV
AGC
ALC
R8V
–5V
ICL
5V
ICH
H5V
8V
MEASUREMENT CONDITIONS
DISPLAY FREQ. :14.10000MHZ
MODE
MEASURE
14V
5V
HV
J861
14V
14V
14V
SPE
14V
AFO
SPE
AGC
TMD
8V
PWRK to DISPLAY
ALC
board J321
GND
T8V
GND
GND
GND
R8V
MICI
–5V
8V
MSND
5V
MICE
TRVI
SQSS
J891
MCK
W151 LFMD
LMFD
W3563 DRES
R
W3565
G
B
HSYNC
W3564
VSYNC
GND
W3562
GND
GND to DISPLAY
14V
GND board J301
W854
–8V
–8V
14V
5V
14V
14V
8V
10 - 7
L272 L273
LS-450 Q273 LS-450
Q279 C289
2SK882
2SC4081 0.0022
R292
22k
14V
T8V
–8V
H5V
2IF
8V
14VA
HV
AGC
ALC
R8V
–5V
5V
:USB
:VOLTMETER, OSCILLOSCOPE
J201
L201
GND
HF50ACC322513-B
8V_
8V
FMTL
8V_
GND
–5V_
–5V
GND
L202
–5V_ HF50ACC322513-B
GND
–8V_ –8V
GND
L203
–8V_ HF50ACC322513-B
CP202
DRAF
GND
to DSP-A CP203 CP211
DTAF
board J2001
AGC
GND
GND
CP204
DMAF
GND
CP205
D5VA D5VA
GND
L204
D5VA
HF50ACC322513-B
GND
D5VA
CP212
GND
CP206
DRIF
DTIF
GND
GND
C209 470
J202
AGRS
3R3V_d
GND
L206
3R3V_d
HF50ACC322513-B
M5V_d
GND
CP228 L205
GND
HF50ACC322513-B
NSQO
DSDR
DPGI
UNSB
MODS
FMNS
MCK
to DSP-A
CALS
board J2002
DSFW
ACKS
MDAT
DSRS
DSFR
AMS
CTFL
TXS
RTDT
MSL1
GND
DSKY
GND
GND
CP242
CP271 CP272
Q276
2SC4081
Q278
R285 UNR911HJ
2.2M
R284 Q275
47k
2SA1576
Q274
2SC4081
14V
T8V
–8V
H5V
2IF
8V
14VA
HV
AGC
ALC
R8V
–5V
5V
M5V
D111 C121
IC802
1SV308 0.1
TA7805F
M5V
8V
I O
G
T8V
R514
47k
IC803
TA7805F
8V
I O
G
R804
470
AGC
L261
LS-469
Q804
2SD1801
R802
47
IC805
AN79L05M
–8V –5V
I O
G
ALC
T8V
IC801
BA033T
3R3V 8V
O I FORV
G
5V
CP502
TRV
CP501
Q803
DTA144EE
TRVI
D502
R504
MA2S111
33k
Q801
2SC4081
Q501
UMH11N
4
BANV
5 3
R107
6 2
100k
2V
1
6
– 7 BANS
5
+
R108
470
IC101b
NJM4558M
4V
3R3V_d
3R3V
A
8V
L274
100mH
Explanatory notes
VOLTAGE LINE
TX LINE
RX LINE
B
14V
C
T8V
D
-8V
E
F
8V
G
H
HV
I
J
R8V
K
-5V
L
M
N
L111 L112
LS-468 LS-468
C113 470p D113 1SV308
O
D114 1SV308
P
Q503
2SC4081 R3787
10k
MODS
Q3773
UNR9211J
AMS
Q504
2SC4081
Q
R
Q261 S
2SK882 T
U
POCV
V
Q505 Q506
DTC144TE
2SA1576
FORV
W
R517
R516 Q521
470k
2SA1576
22k
-5V
X
R511
220k R512 3.3M
Y
R505
6 D504 MA2S728
– 7
220k
5
+
R513
330
IC551b
NJM2058M
Q502
UMH4N
4
5 3
6 2
PO
1
Q507
DTA114EE
Z
AA
AB
AC