![background image](http://html.mh-extra.com/html/icom/ic-a23/ic-a23_service-manual_612408036.webp)
9.3V
TX: 3.2V
RX: 0.0V
TX: 1.8V
RX: 0.0V
TX: 0.0V
RX: 1.2V
TX: 0.0V
RX: 4.8V
TX: 0.0V
RX: 0.0V
TX: 0.0V
RX: 0.2V
TX: 0.0V
RX: 4.4V
TX: 0.0V
RX: 0.1V
TX: 0.0V
RX: 1.2V
TX: 0.0V
RX: 0.2V
TX: 0.0V
RX: 4.2V
TX: 0.0V
RX: 1.2V
TX: 0.0V
RX: 0.2V
TX: 0.0V
RX: 1.4V
TX: 0.0V
RX: 4.8V
9.6V
TX: 9.0V
RX: 2.1V
TX: 9.0V
RX: 9.3V
TX: 8.3V
RX: 8.7V
TX: 9.1V
RX: 9.2V
TX: 0.0V
RX: 2.5V
9.3V
TX: 3.2V
RX: 0.0V
TX: 3.5V
RX: 0.0V
TX: 4.9V
RX: 0.0V
1.2V
5.0V
INPUT: 9.6V
C9
0.001
C13
15p
C15
1p
C14
15p
C11
1p
C12
1p
C16
0.5p
C18
0.001
C28
0.001
C20
0.001
C23
0.001
C22
27p
C19
0.001
C21
82p
C24
0.001
C30
39p
C25
0.001
C31
0.001
C32
0.001
C33
0.001
C27
56p
C26
0.1
C17
0.1
C61
0.001
C87
47p
C84
0.001
C85
10p
C78
47p
C80
0.001
C81
270p
C89
0.01
C88
0.01
C90
0.01
C98
0.001
C96
0.1
C95
0.01
C94
0.01
C117
0.1
C118
100p
C179
0.1
C178
0.01
C199
68p
C177
15p
C175
33p
C198
2p
C167
0.001
C166
82p
C200
0.001
C165
15p
C168
0.1
C174
0.001
C173
15
C170
0.001
C164
2p
C163
2p
C162
2p
C128
0.001
C127
0.001
C186
0.001
C187
0.001
C188
4.7
C539
0.1
C538
0.1
VIN1
VOUT1
GND
D
ATA
CLK
VCC
VOUT2
VIN2
5
6
7
8
1
2
3
4
C119
0.001
C120
0.001
C121
10
C156
0.001
C151
0.001
C149
0.001
C150
8p
C148
47p
C155
33p
C153
0.001
C154
0.001
C152
0.001
C160
0.001
C159
0.001
C161
0.001
C158
0.5p
C157
0.001
R95
180k
C107
0.1
R98
150k
C111
0.01
C108
0.01
C114
0.01
R97
4.7k
C109
470p
C112
0.1
R96
56k
R93
2.2k
R88
100k
R87
68k
C104
0.01
C106
0.01
R89
470k
C101
0.001
R90
4.7k
R92
56k
R91
2.2k
R85
4.7k
R84
100k
R82
18k
C100
0.01
C102
0.47
R79
390k
R80
56k
R77
6.8k
R76
10k
C99
10
R75
1k
C97
0.01
R74
100k
C103
0.1
R83
470k
R81
1.5k
C303
24p
C301
9p
C304
68k
C302
150p
C300
82p
C201
22p
C91
68p
C92
0.001
C93
0.001
R68
560k
R69
3.3k
R156
1.2k
R66
1.8k
C204
33p
C205
3p
C203
15p
C206
18p
C83
0.001
C82
0.001
C66
3p
C110
0.1
R57
220k
C70
0.5p
C67
0.001
C74
0.5p
C69
0.001
R51
47
C73
2p
R52
220k
C68
0.001
R53
220k
C191
0.001
C192
0.001
C72
5p
R54
220k
C71
82p
R64
100
R59
1M
R61
10k
R62
470k
R60
100k
R63
220k
R65
56
R58
220k
C193
0.001
C64
0.47
R49
47
R44
150k
C62
0.001
R46
150k
R47
100k
C190
0.001
C65
0.001
R45
47k
R48
560k
C60
150p
R43
220k
C8
0.001
C6
3p
C10
0.001
C4
7p
C55
18p
C7
18p
C3
22p
C5
27p
C56
0.001
C53
22p
C54
39p
R4
100k
R3
100k
R6
33k
R5
33k
R8
270
R9
47k
R10
10k
R21
1k
R22
2.2k
R20
56
R17
12k
C34
39p
C29
0.001
C35
33p
R19
10k
C36
0.001
C402
0.001
C44
0.001
R36
100
R38
100
C45
0.001
R37
470
R33
220
C42
0.001
C43
39p
C47
0.001
R35
10k
C46
0.001
R34
10k
R39
10k
C48
0.001
C50
1
C52
0.1
C51
0.001
C49
2.2
R40
3.3k
C113
10
R102
100k
R101
330k
R100
100k
C115
0.22
C197
0.01
R157
100k
C281
0.1
R138
470k
C180
0.001
R137
47k
R131
10k
R130
2.2k
C172
0.001
R129
6.8k
R126
220
R128
220
R125
100
R124
68k
R123
470
R127
6.8k
R121
470
R119
470
R120
56k
R118
15
R116
1.5k
R115
47k
R114
270
R117
220
C124
0.001
R105
10k
R104
22
R103
22
C123
0.001
C122
0.001
C125
0.001
C126
0.01
C195
100
R139
10
C181
0.1
C182
22p
R140
180
C183
4.7
C196
0.001
C184
100
C185
4.7
R147
12k
R145
10k
R141
10k
C595
0.01
C594
0.0027
C596
150p
R557
39k
C541
4.7
R551
100k
R553
100k
R554
500k
R555
47k
R155
1M
R154
1.5M
R134
2.2k
R135
1k
C169
1
R133
100k
R146
10k
R148
1k
C537
0.001
R150
100k
R149
10k
R300
1k
R301
820
C202
1
C340
100
R110
1k
C140
0.001
R109
10k
EXTSP
EXTPTT
EXTPTT
EXTMIC
STDET
EXTMIC
STDET
C565
0.001
C567
0.001
C572
12p
R107
150
R108
18
C130
100
C142
0.001
C143
0.001
C144
0.001
C145
0.001
C146
0.001
C141
0.001
SPE/MICE
R55
270k
R56
TBPS1R154K475H5Q
C58
7p
C76
5p
C75
33p
R112
150
C171
0.001
R113
27k
R111
10k
C129
0.01
R106
100k
R160
47k
3
1
4
R162
100k
C540
4.7
R163
100k
R161
270k
IC14
NJM2107F
5
2
R556
47k
R550
100k
C597
0.01
R158
22k
WXC
WXC
EMBI
AFC
EMBI
AFC
SBATT
VCC
VCC
MOD
BEEP
+5V
CHGC
CHGC
HV
EMBI
SBATT
VCC
CHGC
HV
SBATT
VCC
CHGC
HV
UNLK
VOLDATA
JACKDET
VOLCK
EXTMIC
EXTPTT
VREC
R159
100k
R549
120k
R28
100
C41
0.001
R29
15k
R30
220
R31
33k
R32
100
C37
10
R26
100k
C38
0.001
C39
0.001
R25
1k
R27
1k
C40
8p
R24
10k
R23
10k
R15
33
R16
50k
R14
22k
R18
33
R12
47k
R13
68k
R11
22k
R7
270
R2
100
C77
1.5p
C79
82p
R78
150k
R71
1.2k
R72
470
R70
2.2k
R73
100k
R86
2.2k
C116
0.22
R153
1M
R99
220k
Q7
2SB1132
Q8
2SC4211
Q20
UN9115
Q19
UN9210
VSS
NO
AO3
AO4
AO5
AO6
VDD
VCC
IC4
M62354GP
CLK
AO1
AO2
GND
DO
LD
D1
NC
FIN1
1
GND
2
CLK
3
DATA
4
STB
5
BS1
6
BS2
7
FIN2
8
CP2
9
GND
10
LD
11
BO
12
XOUT
13
XIN
14
VCC
15
CP1
16
IC3
TB31207AFN
Q33
2SC4116
Q34
UN9210
Q32
2SC4226
Q31
2SC4226
Q30
2SC4226
Q29
2SC4403
Q28
2SC4403
Q27
2SC4403
Q24
HAT1024R
Q23
UN9210
Q22
2SB1132
Q10
2SD1819A
Q11
3SK230
Q1
UMS1
Q2
2SK2974
Q3
2SK2973
Q4
2SC3357
Q6
2SC4403
Q5
2SC4211
Q14
2SD1819
IC1
TA31136FN
Q13
2SC4215
Q12
3SK151
OSCIN
1
OSCOUT
2
MIXOUT
3
VCC
4
IFIN
5
DEC
6
FILOUT
7
FILIN
8
AFOUT
9
QUAD
10
IFOUT
11
RSSI
12
N-DET
13
N-REC
14
GND
15
MIXIN
16
Q16
2SC4215
Q17
2SC4215
Q15
2SC4215
Q18
2SC4211
IC13
NJM2107F
Q21
UN9210
STR
1 2
3
Q1
4
Q2
5
Q3
6
Q4
7
VSS
8
1 2
3 4
5
6
7
8
QS
9
QS
10
Q8
11
Q7
12
Q6
13
Q5
14
OE
VDD
IC5
BU4094BCFV
16 15
9
10
11
12
13
14
16 15
CLK
D
1
2
3
4
5
6
7
8
IC2
TC4W53FU
NC
1
VCC
2
NC
3
VIN
4
RIPPLE
5
NF
6
PHASE
7
PREGND
8
PWGND
9
POUT
10
IC6
TA7368F
IC505
M62429FP
IC510
TC75W51FU
L25
EXCCL3225U
S1
1
G1
2
S2
3
G2
4
D2
5
D2
6
D1
7
D1
8
L28
EXCCL3225U
L26
HF50ACC
453215P-T
L29
2.2 H
L34 2.2 H
L35 EXCCL3225U
L32 2.2 H
L33 2.2 H
L31 2.2 H
L36
2.2 H
L21
68nH
L22
82nH
L23
68nH
L5
60nH
L6
19.5nH
L7
36nH
L8
27nH
L9
EXCCL3225U
L10
39nH
L11
68nH
L12
80nH
L13
0.1 H
D6
MA77
D5
1SV246
D7
MA111
D18
MA111
R94
100
L301
0.22 H
L300
0.22 H
L41
0.82 H
L40
LB-342
D24
MA304
D25
MA77
L39
82nH
L24
2.2 H
L43
2.7 H
L44
6.8 H
D15
MA304
D16
MA304
D17
MA77
D14
MA304
L16
50nH
L15
54nH
L18
56nH
D9
MA77
D8
MA77
D13
MA304
L4
0.82 H
L3
65nH
L2
65nH
L1
50nH
D1
MA77
D2
MA728
D4
1SV246
L14
4.7 H
T+5
D100
MA8024
L42
4.7 H
D26
HVU17
Q36
XP1501
Q35
2SB1201
L38
0.27 H
L37
0.27 H
D23
MA133
Q25
2SB1132
Q26
UN9211
D27
MA111
D19
RB060L-40
D21
MA133
D20
SB07-03C
D22
MA2S728
X1
CDBCA450CX24
FI1
30.050 MHz
D3
MA728
FI2
CFWC450E
3
2
1
5
4
W12
VCC
MP2
1
2
3
4
R5
X2
29.600MHz
EP1
W17
1
3
2
4
5
SDATA
+5V
+5V
+5V
+5V
R5C
VORON
VORDET
RSSI
RFDETV
TXC
VCC
DETO
+5V
ANLC
DETMUTE
DETMUTE
R5C
R5C
CHGC
EXTMIC
VORDET
VORDET
PCK
RSSI
RSSI
+5V
+5V
UNLK
PSTB
PDATA
RFDETV
RFDETV
OE
VORON
VORON
TXC
TXC
PTT
LIGHT
VREC
JACKDET
VOLCK
SCK
VOLDATA
RFSTB
RFSTB
EXTPTT
TO
LOGIC
UNIT
J1
BEEP
MOD
SBATT
HV
SDATA
VCC
VCC
HV
DASTB
GND
GND
GND
GND
GND
GND
GND
GND
GND
35
34
33
32
31
30
29
28
27
26
25
24
23
22
36
37
38
39
1
20
40
7
8
9
10
12
13
14
16
15
18
2
3
4
5
6
11
17
19
21
J3
DET
O
S1
JPM1990-2711R
S2
JPM1990-2711R
LIGHT
LIGHT
PTT
1
2
3
4
5
6
7
8
3
2
1
5
4
CP1
W15
J1
HV
VCC
DCIN 9 — 12V
HV
HV
HV
CHG
SBATT
(9V~9.6V)
SP1
1
2
P1
MP1
1
2
J4
BP-200L
EXT SP/MIC
(4pin/d=3.5)
J2
W16
1
2
3
CHASSIS UNIT
ANTENNA
1
2
J1
W14
RF UNIT
LEFT SIDE
RIGHT SIDE
11 - 2
11 - 2 RF UNIT