Icom IC-7400 Service Manual page 69

• BLOCK DIAGRAM (2/2)
Q241
D261 3SK131
HSB88WS
IF
1 LPF
AMP
FI231B
FL315
AGC
XTAL
BPF
ATT
2
D272
1SV271
ATT
3
LPF
D271
HSB88WS
LPF
4
Q301
2SC4673
LO
LPF
AMP
LPF
Q302 DTA114EE
Q303 DTC114EE
SW
64.485-238.455MHz
LPF HPF
LPF
LPF
Q1521
UMD3N
SW
IC1001
BU4094BCFV
LOF4
Q1581
UMD3N LOF3
LOF2
SW LOF1
Q1561
UMD3N
SW
PST5
BPF BPF
Q1902
X1901
2SC4081
Q1901 2SC4403 CR-337A
D1901 MA357
(32.0MHz)
CLK
D/A x2 BUFF
Q1903 2SC4081
Q1904 2SC4403
IC1601 Q1601
5V CAL
SC-1287 2SC4081
14V
DDS AMP X1902
CR-338
OPTION
LDRS
PST3
Q1003
UMD3N
LEVEL
UNLC
CONV
Q231 Q211/Q212
2SK2171 2SK1740
IF
LPF
AMP
FI231A
FL-315
PRE1
XTAL
BPF
Q271
2SK882
IF
PRE2
AMP
DRIV ALC
POFF
1LO
B9S
D502-D504 Q502
1SV217 3SK177
BPF
Q1401 D1401/D1403 1SS315
2SC4226 L1402 LR-317
ATT AMP x2
TNV2 PR3S
TNV1
V3S
Q1402
DTA114EE
SW
Q1281 IC1802
Q1201 2SK508 2SC4405 mPC1678G
D1201 MA338
Q1202
BUFF ATT
2SC4213
V1S
SW
Q1221 2SK508
SERI- D1221 MA338
PARA
Q1222
2SC4213
V2S
SW
Q1241 2SK508
D1241 KV1470
Q1242 IC1801
2SC4213 MC145170
V3S
SW
Q1261 2SK508
D1261 KV1470
PLL
Q1262
2SC4213
V4S
SW
Q1051
2SC4081
4V VCO RIPPLE
FIL
LOOP
FIL
IC1051
TA78L05F
+5
8V 5V PLL
REG
PST2
FAN CONTROL VOLTAGE
Q181/Q182
2SK2171
0.03-
1.6MHz
ATT
PRE
LPF B0
AMP
1.6-
2.0MHz
HPF
LPF B1
IC191 2.0-
mPC1658G 4.0MHz
BPF B2
PRE
ATT
AMP
4.0-
8.0MHz
BPF B3
8.0-
11.0MHz
IC323
TD62783AF
BPF B4
CURRENT
11.0-
DRIVER
15.0MHz
BPF B5
15.0-
22.0MHz
BPF B6
IC324
22.0-
TD62783AF
30.0MHz
BPF B7
CURRENT
DRIVER
50.0- Q322-Q325/Q328
54.0MHz DTC114EE
D321-D324
BPF
B8
DAN222
30-50MHz
54-60MHz
BPF B8W
IC161
TA4001F
PRE1
YGR 144MHz PRE2
BPF
AMP
POFF
ATTC
B9T
B9R
D501
1SV217
PRE 108-174MHz
BPF ATT HPF
AMP
ATTC
IC1081
TC7S08F
MKR MARKER
SW
BPF
AMP LPF
Q1801
UMD3N
SW
Q1302
2SC4081
Q1301 2SK210
D1301 MA357
LOOP
BUFF
FIL
Q1102
2SC4081
IC1101
SC-1246A
AMP
PAFS
DBLS
PHASE
Q1101
MKRS
2SC4081 DET
DIVOUT
FANH
AMP
FANM
FANL
FI1101
CON2
CFECA10.8MD11
LDRS
CERAMIC PST1
D/A DDS
BPF PDAT
PCK
Q1103
2SC4081
FAN Q2002-Q2004
DTC114EE
AMP SW
RF UNIT
ANT2 ANT1
HRX
ATT
RL3
RL1
ATTC
IC151 D15 HSM88AS
CURRENT
mPC1678G D23 HSM88AS
DET
IC9 NJM203M
YGR
ATT ATT
AMP
RL2
IC321
BU4094BCFV
RL1
B0S SERI-
PARA
B1S
B2S
B3S
RMDT
B4S
RBST
B5S
RMCK
B6S
B7S
RL4
IC322
BU4094BCFV
B8S
B8WS
SERI-
LPF
PARA
ATTS
PR3S
B9S
PREAMP
/BPF
SELECT
D8/D9
HSM88AS RESIST
Q5
RTXS DET
2SK515
D4 DWA010
D5 HSM88ASR
PHASE
IC2 TC74ACT32F
DET
IC3 TC74AC112F
IC14 TC74AC04F
SWR
D1/D2
HSM88AS DET
VRX
FOR
REF
YGR
Q2 Q1
2SC1971 2SK2973
PRE PRE
Q201/Q202
DRIVE DRIVE
RD70HVF1
PWR 144MHz
AMP
Q1/Q2
2SK2975
Q204/205
RL2
DTC114EU/DTA114EU
DRIVE
AMP
BIAS
DRV
Q5/Q6
BOARD
RD100HHF1
PWR
AMP
Q14,Q15/Q16
DTC114EU/DTA114EU
BIAS
ICH
ICL
HV
IC1
TA78L05F
+5
H5V
REG
RL1
14V
IC2 Q9
TA7805S DAP222
+5 RELAY
5V
REG CTRL
IC3
TA7808S
+8
8V
REG
P1
3 6
H14V
COMMON
GND GND
FILTER
2 5
P14V
1 4
CHASSIS UNIT FILTER UNIT
10 - 2
CANT
TUNER BOARD
TUNING
NET.
Q14/Q16
DTC114EU
TUNER THRU
CTRL
Q12
DTC114EU
T/R TRC
CTRL
Q23 DTC114EU
Q24 DTA114EU
CT8V CTRL
IC5
M38022M2
IC4
NJM4558M CIST
AN2 CPU
AMP
AN3 CIKY
IC4
AN0/AN1
NJM4558M
AMP
IC6
X1
X24C04S8
CR-569
IC1
(6.144MHz)
NJM4558M
EEPROM
AMP
IC13 CTRL UNIT
TA7805F
+5
14V 5V
REG
D602/D603 144MHz ANT
HSU88
RL601
SWR
LPF
DET
VPAO
VREF
VFOR
THML
1.9MHz
LPF
L1
3.5MHz
LPF
HF/50MHz
L2
7MHz
LPF
L3
10/14MHz
LPF
F1
(FGB 5A)
L4
18/21MHz
LPF
L5
24/28MHz
LPF
L6
PWRS
50MHz
LPF
L7
L8
IC502 IC501
BU4094BCF TD62783AF
SERI- CURRENT
PARA DRIVER
FSTB 14VS
MDAT
MCK
PA UNIT