![background image](http://html.mh-extra.com/html/icom/ic-2720h/ic-2720h_service-manual_611472046.webp)
REF_OSC
REFCON
5VS
5VS
8V
8V
8V
L_UNLOCK
REF_MOD
L_VCO8
REFCON
5VS
5VS
REF_CON
L_VR5
L_RXL0
L_UR5
UDETS
8V
L_DET_MUTE
VDETS
8V
PLLCK
MOD_SET_DATA
8V
5VS
5VS
8V
5VS
5V
HV
BUS LINE2
BUS LINE1
8V
5VS
5V
HV
BUS LINE2
BUS LINE1
HVC321B
D3
REFCON
5VS
8V
5VS
5VS
RX: 3.87V
4.68V
RX: 0.58V
7.11V
RX: 4.67V
RX: 7.11V
0.047
C25
W3
W2
W4
W1
0.001
C12
VCO UNIT
8V
100k
R1020
8V
5VS
MAIN UNIT(2)
J5
10k
R55
0.001
C6
C81 0.001
1p
C14
GND
L_VCO8
100k
R1018
100p
C1055
0.0056
C1007
i
a
h
TC4S66F
IC2
R_DET_MUTE
UDETS
g
f
e
d
c
b
DTCS
DTCS_SEL
MOD_SET_DATA
PLLCK
RIPTMOD
MODIN
DATAMOD
L_R5CTRL
R_R5CTRL
R_AM
L_AM
UAFO
L_DET_MUTE
VDETS
VAFO
L_DTCS_IN
L_WXALT
R_DTCS_IN
R_WXALT
8V
(3)
UNIT
MAIN
5V
5VS
HV
BUS LINE2
l
k
j
BUS LINE3
100k
R2274
0.001
C73
5VS
REF_CON
L_UR5
L_VR5
GND
L_RXLO
5VS
REF_CON
L_UR5
L_VR5
GND
L_RXLO
0.001
C75
REF_CON
C74 0.001
0.001
C56
L_PLLSW
OUT1
PLLDATA
PLLCK
L VCO8
L_VCO8
L_PLLSW
OUT1
PLLDATA
PLLCK
REF_CON
L_UNLOCK
L_PLLSW
REF_MOD
8V
L_LO_SW
REF_OSC
OUT1
PLLDATA
PLLCK
MOD
L_VCO_SHIFT
OUT4
VHFYGR
DTC144EU
Q4
DTA143ZU
Q9
DTC143ZU
Q5
R40 4.7k
0.001
C86
150
R62
27p
C87
56p
C88
27p
C89
1k
R60
MA2S077
D16
68n
L13
68n
L14
DTC144EU
Q10
0.001
C72
1k
R61
1
R51
8p
C69
1p
C71
2.2k
R54
MA2S077
D7
D15 MA2S077
27
R59
0.001
C85
3.3
R57
27
R58
0.001
C83
1k
R56
C84 0.001
C82 0.001
5
6
7
8
4
3
2
1
µ
PB1509GV
IC3
2SC5231
Q8
0.22
µ
L12
10k
R46
1.5k
R50
47p
C68
0.001
C66
C61 0.001
4p
C62
1.8k
R47
0.5p
C60
100
R45
22p
C55
1p
C51
1k
R44
0.1
µ
L7
2SC5231
Q7
1.8k
R43
120
R39
1p
C40
R42 10k
C44 0.001
C43 0.001
820
R36
2SC5231
Q6
10k
R35
C39 18p
C38 22p
10k
R32
C2012C
L4
4.7k
R31
0.001
C36
C2012C
L3
12p
C37
0.001
C42
47
R34
0.001
C33
47p
C8
1k
R30
0.3p
C34
100k
R28
D6 MA2S077
0.001
C35
D5 HVC321B
C31 0.001
47k
R29
2.2M
R27
22k
R26
0.1
C30
R25 1k
D4 HVC321B
C29 0.1
0.47
µ
L2
1.2k
R23
2.2
C28
1.2k
R24
0.001
C27
0.1
C78
3
2
1
4
5
0.001
C50
R48 4.7k
MA2S077
D10
4.7k
R52
2.2k
R49
27n
L11
6p
C54
6p
C57
6p
C52
33n
L6
18p
C48
2.2k
R41
MA2S077
D11
7p
C65
7p
C58
MA2S077
D9
12p
C46
10n
L8
8p
C49
0.001
C41
100
R37
15p
C47
27p
C53
15p
C63
0.001
C64
39n
L9
39n
L5
6p
C45
12
R38
12
R33
MA2S077
D8
1SV308
D13
0.001
C70
120
R53
1SV308
D12
56n
L10
18p
C59
18p
C67
C32 0.001
4.7k
R1049
C9 47p
C1 47p
C4 47p
C11 0.001
C3 0.001
C7 0.001
100
R18
100
R21
0.22
C26
1.2k
R22
1.5k
R20
22
R11
0.1
C24
470p
C23
2SC4116
Q3
2SA1586
Q2
18k
R13
3p
C80
10k
R17
3.3k
R19
22p
C79
27k
R15
DA221
D2
10p
C22
2.2M
R63
10p
C21
68n
L1
0.001
C18
2SC4403
Q1
10k
R6
330
R2
22k
R5
220
R7
1k
R4
0.001
C15
22k
R8
27p
C19
0.01
C13
HVC376B
D1
100k
R3
10k
R1
56p
C16
R9 150
C17 4p
12.8MHz
CR-718
X1
R10 22k
0.1
C20
470p
C77
MA2S111
D14
47p
C76
MB15A02PFV-1
IC1
9
10
11
12
13
14
15
16
8
7
6
5
4
3
2
1
R16 10k
R14 10k
R12 10k
CLOCK
DATA
LE
FC
NC
FOUT
P
B
FIN
LD
GND
DO
VCC
VP
OSCOUT
OSCIN
47n
L1002
0.001
C1063
4.7k
R1048
C10 0.001
C5 0.001
C2 0.001
J4
J3
J2
J1
0.01
C1296
0.001
C1297
100k
R1302
10k
R1301
68k
R1062
0.01
C1027
1.2k
R1021
68k
R1015
100k
R1004
0.0022
C1005
0.022
C1012
10k
R1029
10k
R1028
15k
R1035
0.033
C1035
68k
R1055
68k
R1044
0.0068
C1041
0.0018
C1028
1
2
3
6
4
5
XP4601
Q1004
C1046 0.001
C1050 0.015
R1071 2.2M
C1059 0.001
R1075 2.2M
R1076 2.2M
2SJ144
Q1011
330
R1052
6
5
4
1
2
3
47k
R1039
C1054 0.01
12k
R1070
22k
R1066
0.033
C1045
39k
R1064
680k
R1060
XP6501
Q1008
3.3k
R1034
22k
R1037
0.015
C1030
0.0018
C1022
1.5M
R1023
0.0039
C1020
0.001
C1011
10k
R1299
100k
R1300
0.001
C1295
0.01
C1294
68k
R1061
0.01
C1025
1.2k
R1019
68k
R1012
100k
R1003
0.022
C1010
0.0022
C1004
10k
R1027
10k
R1025
15k
R1031
0.033
C1033
68k
R1054
68k
R1043
0.0068
C1038
0.0018
C1026
XP4601
Q1003
1
2
3
6
5
4
47k
R1038
330
R1051
3
2
1
4
5
6
2SJ144
Q1010
R1077 2.2M
R1074 2.2M
C1058 0.001
R1069 2.2M
C1053 0.01
C1049 0.015
C1044 0.001
12k
R1068
22k
R1065
39k
R1063
0.033
C1043
680k
R1059
XP6501
Q1007
3.3k
R1033
22k
R1036
0.015
C1029
0.0018
C1021
0.0039
C1019
1.5M
R1022
0.001
C1009
DTA143ZU
Q1006
DTA143ZU
Q1005
DTA114YU
Q1002
DTA114YU
Q1000
10k
R1165
47k
R1288
47p
C2197
2SC4116
Q1023
3.3k
R1162
10
C1125
47p
C2198
C2182 10
18k
R2249
C1062 1
82p
C1048
82p
C1040
0.01
C1037
68p
C1042
1.2
µ
L1000
2SC4215
Q1009
39p
C1051
10k
R1067
0.01
C1052
0.56
µ
L1001
2.2M
R1072
0.01
C1057
5p
C1066
2SC4116
Q1012
470
R1083
0.022
C1061
47k
R1085
R1082 100
100
R1010
120k
R1058
10
C1278
R1057 180k
C1047 0.033
R1056 1.5k
220k
R1047
220k
R1026
NJM12902V
IC1000
+ -
+
-
+ -
+
-
8
9
10
11
12
13
14
7
6
5
4
3
2
1
100k
R1017
100k
R1016
180p
C1016
150k
R1024
0.068
C1015
470
R1013
C1008 0.047
R1006 15k
C1018 1
R1030 5.6k
R1046 100k
R1042 100k
C1034 10
C1032 0.1
R1040 15k
R1032 15k
0.0039
C1036
390p
C1039
22k
R1050
68k
R1053
R1041 22k
C1024 0.01
DTC144EU
Q1001
0.01
C2200
39k
R2263
220k
R1045
10
C1023
10k
R2262
0.068
C1017
0.033
C1006
39k
R1009
3.9k
R1005
M62363FP-650C
IC1009
13
14
15
16
17
18
19
20
21
22
23
24
VIN5
VOUT5
VOUT6
VIN6
DO
VDAREF
RESET
GND
VIN7
VOUT7
VOUT8
VIN8
VIN4
VOUT4
VOUT3
VIN3
DI
CLK
LD
VDD
VIN2
VOUT2
VOUT1
VIN1
12
11
10
9
8
7
6
5
4
3
2
1
5V
BUS LINE2
BUS LINE1
8V
5VS
HV
(1)
UNIT
MAIN
BUS LINE1
10 - 3