![background image](http://html2.mh-extra.com/html/icom/ic-400pro/ic-400pro_service-manual_3993468033.webp)
11-2 MAIN UNIT
VOLTAGE LINE
Explanatory notes
TX LINE
RX LINE
COMMON LINE
R77
8V
10k
J1
SCK
SI
SO
CIRQ
CCS
GND
GND
DISC
DET
BEEPO
AFONO
OV12
OV12
DAST
OPT3
OPT2
OPT1
SIGO
BUSY
R266 47k
R267 27k
R268 10k
R265 18k
8V
CPU5V
5V
R270 100k
R264 68k
R269 100k
R263 1M
R262 1M
R261 1M
R271 100
MIC
CP24
5V
CPU5V
8V
CP23
C311
0.001
SCK
SI
OV12
SO
DAST
CIRQ
CCS
OPT3
REM
OPT2
DISC
OPT1
DET
SIGO
BEEPO
RMUTE
MMUTE
REM
RMUTE
MMUTE
MCIN
MCOT
PTTO
PTTI
BUSY
AFONO
MAIN UNIT (1)
to
Optional
unit
J2
DIM
DAST
OPT3
OPT2
OPT1
PTTO
PTTI
REM
SCK
SI
SO
CIRQ
CCS
MIC
EPTT
NC
BEEP
PWON
8V
GND
GND
TONE
TENC
NOIS
EXOE
EXST
UNLK
PLST
CDEC
SDEC
OV12
RSSI
LVIN
TEMP
BATV
NC
NC
5V
CPU5
AFO
J1
8V
CL0
AFO
PTT
MICE
MIC
GND
CLI
to
mic
jack
J2
DIM
DAST
OPT3
OPT2
OPT1
PTTO
PTTI
REM
SCK
SI
SO
CIRQ
CCS
MIC
EPTT
BEEP
PWON
8V
GND
GND
TONE
TENC
NOIS
EXOE
EXST
UNLK
PLST
CDEC
SDEC
OV12
RSSI
LVIN
TEMP
BATV
NC
NC
NC
5V
CPU5
AFO
FRONT UNIT
R147
MICIN
5V
8V
CPU5V
1k
R148
1k
R143
1k
R149
1k
R150
1k
R141
1k
C204 47p
C201 0.1
C202 0.1
C207 0.001
C208 0.001
C209 0.001
C210 0.001
C203 0.1
C388
180p
R145 8.2k
R144 1k
R146 1k
DIM
DAST
OPT3
OPT2
OPT1
PTTO
PTTI
REM
EXOE
EXST
UNLK
PLST
TONE
TENC
NOIS
CDEC
SDEC
CCS
MAIN
UNIT
(2)
PWON
BEEP
EPTT
BATV
R110
8V
CPU5V
5V
5V
5V
CPU5V
5V
47
C162
0.01
R220
100k
REF
BAL
C163
10
R222
10k
C164
0.001
R219
100k
R309
100k
R310
100k
D21
HVC362
L10
1.8
µ
BUS LINE2
C161
100p
C160
9p
X2
CR-741
R105
47k
D20
MA2S111
R106
82k
C158
100p
R104
1.2k
C156
47p
C157
100p
Q19
2SC4215
C142
0.001
R101
1k
C143
0.001
C141
0.001
R100
47k
9
10
11
12
13
14
15
16
8
7
6
5
4
3
2
1
CLOCK
DATA
LE
FC
NC
FOUT
P
B
FIN
LD
GND
DO
VCC
VP
OSCOUT
OSCIN
VCC
8V
CPU5V
5V
5V
IC4
MB15A02PFV-1
C152 47P
C153 47P
C154 47P
C151
0.1
R103
150k
C155
47p
C140
0.1
C377
180p
8V
CPU5V
5V
VCC
8V
CPU5V
5V
8V
CPU5V
5V
VCC
L29
1.8
µ
UNLK
SCK
SO
PLST
R97
1k
R95
10k
C146
0.1
C138
0.001
C124
1.5p
R89
10k
C147
1
C130
0.047
R96
3.9k
Q18
2SK880
R92
120k
R91
47k
C132
0.001
R90
470k
LVIN
CP1
C145
47p
C314
8V
0.01
R98
2.2k
R87
10
R86
220k
C148
10
Q17
2SC4116
C128
4p
C129
0.5p
D17
HVC350B
C144
47p
L28
1.8
µ
D16
HVC350B
D18
MA368
C125
6p
L27
1.8
µ
L25
11n
C134
6p
C126
9p
R81
4.7
R85
3.3k
C114
7p
C115
4p
Q14
2SC4226
R79
3.3k
C116
0.001
C117
470p
C131
0.001
C133
6p
C394
0.0056
C123
8p
R84
3.3k
C121
9p
C122
8p
R82
4.7
R292
6.8k
Q13
2SC4226
R83
3.3k
C119
0.01
C120
470p
3
2
1
4
5
Q15
XP1214
EP1
R211
56
C299
7p
C298
7p
L32
15n
C113
0.5p
C118
0.5p
R318
1k
C357
0.1
TXC
C139
8V
0.1
Q16
DTC144EU
C111
47p
C112
0.1
R319
1k
R209
47k
C200
0.1
R210
100K
TEMP
C350
1
R291
100k
MOD
F
C337
0.001
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
IC1
TA31136FN
OSCIN
OSCOUT
MIXOUT
VCC
IFIN
DEC
FILOUT
FILIN
MIXIN
GND
N-REC
N-DET
RSSI
IFOUT
QUAD
AFOUT
R44
VCC
5V
220k
C70
390p
R45
100k
R46
330
C71
0.1
I
O
FI2
ALFYM450F=K
R40
1.5k
R39
47
L33
0.82
µ
C307
7p
C305
56p
C306
4p
Q34
2SC4116
Q37
2SC4213
C69
390p
SQIN
R236
1.2k
R237
680k
L35
0.22
µ
C309
0.01
C304
10p
R43
470
C66
0.001
DET
C348
0.001
RSSI
NOIS
C63
47p
C65
0.001
C62
100p
R37
2.7k
C64
0.001
NWC
Q5
DTC144EU
X1
CDBC450CX24
R36
3.9k
R38
100k
C75
10
C67
0.001
R290
680
R34
120k
C60
0.001
C58
0.001
R33
330
R28
1k
C367
1.5p
R8V
R8V
5V
5V
R35
100
C59
0.001
Q4
2SC4215
b
PTTO
PTTI
IC14
BU4066BCFV
1
2
3
4
5
6
7
14
13
12
11
10
9
8
I/O
O/I
O/I
I/O
CONT.B
CONT.C
VEE
VDD
RMUT
RMUT
CONT.A
CONT.D
I/O
O/I
O/I
I/O
IC17
BU4094BCFV
1
2
3
4
5
6
7
16
15
14
13
12
11
10
STR
D
CLK
Q1
Q2
Q3
Q4
VDD
QE
Q5
Q6
Q7
Q8
QS
8
9
VSS
QS
TXC
MMUT
R138
100k
C185
0.001
R117
180k
+
-
12
13
14
IC16
NJM12902V
R121
4.7k
R120 10k
R119
5.6k
R118
12k
R114
12k
C169
0.047
C168
0.047
R115
2.7k
R317
470k
C167
0.1
R122
1.5k
R316
100k
R285
100
DISC
CP2
DET
AFSW
DISC
R125
100k
b
C181
0.1
R124
4.7k
C182
0.0033
R129
100
R128
10k
R130
10k
C287
0.001
MOD
VCC
5V
CPU5V
AFONO
MMUT
MMUTE
MMUT
TXC
EXOE
TMUT
HORNO
BUSY
EXST
SO
SCK
RXC
NWC
RMUTE
BEEPO
AFON
RMUT
5V
8V
CPU5V
5V
8V
CPU5V
5V
8V
CPU5V
R139
100k
RMUT
-
+
2
3
1
IC5
NJM12904V
R185
120k
R183
220k
C177
0.0056
R184
56k
C178
82p
R186
100k
R187
2.2k
R188
4.7k
C179
0.015
R135
120k
R134
56k
R133
150k
SIG
C173
0.1
C172
0.0082
R320
33k
C366
0.1
R136
10k
R140
100k
R137
68k
C175
0.001
C359
1
R112
27k
R111
3.9k
R113
2.2k
C180
47
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
VIN1
VOUT1
VOUT2
VIN2
VDD
LD
CLK
DI
VIN3
VOUT3
VOUT4
VIN4
VIN8
5V
VOUT8
VOUT7
VIN7
GND
RESET
VDAREF
DO
VIN6
VOUT6
VOUT5
VIN5
IC6
M62363FP-650C
C174
10
5V
CPU5V
8V
R231
10k
C283
0.001
DET
TENC
DAST
SCK
SO
BAL
R215
470
SQIN
5V
5V
5V
REF
AFSW
T2
T1
SCK
SI
SO
CIRQ
R142
1k
RSSI
AFO
CP25
TEMP
LVIN
R126
470
C183
0.1
C365
0.1
C184 0.001
R127
47k
7
6
IC5
NJM12904V
5
-
+
BUS LINE1
5V
NC
NC
VCC
C310
VCC
MICIN
0.001
C159
0.1
R93
1k
D37
MA2S111
R78
1k
R80
1k
C297
10p
RXC
V+
GND
8
4
IC5
NJM12904V
C248
0.001
C308
3p
0.1
0.1
C374
C373
C61
100p
OV12
R116
12k
C170
0.001
TONE
C282
0.1
a
b
c
d
VCC
e
C286
0.01
D39
DAP222
D31
DAN222
D40
DAP222
C127
0.3p
L26
11n
L23
0.82
µ
R164
47k
D38
MA2S111
Q38
DTC144EU
R163
W5
10k
8V
CPU5V
5V
590mVrms
(40mVrms at mic terminal)
5.0V
15.3 MHz
1.5Vp-p
7.0V
TX: 0V
RX: 3.0V
TX: 3.0V
RX: 0V
3.1V
4.9V
WIDE:0.9V
NARROW:0.8V
4.9V
TX: 0V
RX: 7.4V
WIDE: 5.0V
NARROW: 0V
MEASUREMENT CONDITIONS
VOLTMETER
Amplitude(Oscilloscope) : 100 MHz
Frequency : 465 MHz
Transmission : 25 W
11 - 2