![background image](http://html1.mh-extra.com/html/icom/ic-f1721d/ic-f1721d_service-manual_4203161046.webp)
COMMON LINE
GPS
LPF
IC37
TA75S01F
C417
0.1
HV
R332
10k
C482
0.001
C474
47p
C455
0.001
Q39
DTC144EU
Q38
DTC144EU
C453
0.001
C423
0.1
C452
0.001
C424
0.1
R336
10k
R337
47
R335
1k
R307
1M
R334
100k
R333
1M
D39
MA2S111
Q33
2SJ144
C395
10
R301
100k
R306
68k
R302
68k
C485
0.001
C477
470
C475
47p
C476
0.001
R360
10k
R372
300k
R373
100k
C459
470
C457
0.1
R359
3.3k
R339
6.8k
R338
6.8k
C429
10
Q34
2SD1664
Q35
DTC114TU
C422
0.001
D37
DA221
C430
0.1
C428
10
C397
0.001
R311
10k
R310
4.7k
Q30
2SA1577
C398
0.001
C396
10
Q27
DTC144EU
Q32
XP6501
1
2
3
4
5
6
R308
22k
R309
22k
C400
0.001
C399
10
C454
0.001
R361
470
Q41
DTC144EU
C478
0.1
C458
10
C460
0.1
R312
4.7k
C387
0.001
C420
1
C418
1
C421
1
C419
1
R305
1k
C394
0.1
C393
4.7
IC36
TA7808F
I
O
G
IC40
AN78L05M
I
O
G
Q42
2SJ377
L41
4.7
µ
H
R371
10k
R374
10k
Q40
DTC144EU
EP7
EP8
CP21
CP24
CP25
CP27
CP28
J8
1
2
3
4
5
6
7
8
9
10
11
12
13
IC35
DS14C232TM
1
C1+
2
V+
3
C1–
4
C2+
5
C2–
6
V–
7
DOUT2
8
RIN2
9
ROUT2
10
DIN2
11
DIN1
12
ROUT1
13
RIN1
14
DOUT1
15
GND
16
VCC
Q44
DTC363EK
R377
10k
D49
MA2S111
C486
0.47
R391
100k
R378
22
D46
DSA3A1
D57
DA204U
D58
DA204U
D59
DA204U
D60
DA204U
Q31
2SB1132
R419
10k
R420
47k
R436
47k
CP41
CP42
CP43
CP43
CP44
CP44
CP45
CP46
CP52
CP53
R439
1k
R440
1k
DC cable
OPC-1414
W3
D66
DA204U
D67
DA204U
CP55
CP56
CP56
25 pin
CONNECTOR
J13
8
10
1
2
3
4
5
6
7
8
9
10
C366
10
DIM
HORN
DISC
F
SIG
SIGO
PWR
T8V
BATV
EPTT
PGI1
PGI3
PGO1
R8V
PA
2
CPU5
CPU5
IGSW
TXD
TXC
TMUT
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
HV
PGI2
D48
DAN202K
D44
DAN202K
D47
DAN202K
R370
100k
CTS
TXD
RXD
RXD
ARXD
CTSI
XCTS
RTS
MD2
TXD2
RXD2
C_RES
TXD
RXD
RDAT
RCK
MD1
MD1
ARES
ARES
ARES
MD1
MD2
GND
C_RES
RXD2
TXD2
ARES
MD1
MD2
C_RES
RXD2
TXD2
A
TXD
XR
TS
8V
8V
8V
8V
Q43
DTC144EU
J7
1
2
3
4
5
6
7
8
9
10
NTXD
NRXO
PG02
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
RCK
CTS
RTS
RDAT
RXD
TXD
HANG
MMUT
BUSY
VCC
3VA
MD1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
C83
0.001
C84
0.001
R57
47k
R58
100k
C82
0.1
C72
0.001
CP9
C85
4p
R431
22k
R432
3.3k
R433
6.8k
C522
1
C523
1
R430
3.9k
C525
0.0047
L4
18nH
D3
MA77
D5
MA77
R81 4.7k
R82 4.7k
R83
4.7k
C125
47p
R79
10k
R78
10k
R77
1k
C122
470p
R129
100k
C129
0.001
C162
10
X4 CDBC450CX24
R131
680
R132
100k
C120
0.001
C121
0.1
1
OSCIN
2
OSCOUT
3
MIXOUT
4
VCC
5
IFIN
6
DEC
7
FILOUT
8
FILIN
AFOUT
QUAD
IFOUT
RSSI
N-DET
N-REC
GND
MIXIN
R98
100k
R97
33k
R125
100k
R126
47k
R84
4.7k
C161
0.1
C127
1
C128
0.001
R128
220k
R130
2.7k
C126
3p
C123
8p
C104
8p
C106
3p
C86
3p
R428
1.5k
R80
270
1
2
3
4
5
C124
1
TXC
F
MOD
RL
V
A
TL
V
A
OUT0
L6
3.3
µ
H
C159
3p
C160
3p
D9
HVC376B
D8
HVC376B
L11
10
µ
H
R150
120k
D12
1SV239
L8
10
µ
H
L7
36nH
L14
80nH
L10
67nH
C493
47p
R149
220k
L9
0.47
µ
H
C192
150p
C157
10p
C530
470p
C154
10p
D6
HVC321B
D7
HVC321B
TXC
VCC
OPC-617
DIM
HORN
GND
AFO
GND
DET
GND
IN
GND
PTT
T8V
R8V
HV
CPU5
CPU5
CPU5
5V
8V
CPU5
5V
8V
CPU5
5V
5V
5V
5V
5V
8V
L21
18nH
C260
47p
C256
470p
R212
100k
Q19
2SC5107
R193
100
C242
470p
Q5
DTC144EU
Q4
2SK880
C194
1p
L15
3.3
µ
H
D13
HVC375B
D11
HVC375B
L13
3.3
µ
H
C190
0.001
C226
33p
R178
4.7
R148
3.9k
R175
1.8k
Q12
2SC4226
C221
0.001
C223
470p
C218
33p
R173
JPW
C217
33p
R147
3.9k
R174
1.8k
Q11
2SC4226
C220
0.01
C222
470p
EP6
C240
0.5p
C239
0.75p
C193
0.1
R362
100k
C461
18p
W2
ANT
C431
470p
R340
47
R342
270
R315
47
D40
1SS375
D38
1SS375
C402
15p
C401
470p
R313
270
C389
18p
C388
18p
C374
0.001
D30
UM9401F
[EUR], [USA]
D29
XB15A407
[USA]
L38
1
µ
H
C346
10p
R299
100
C357
47p
C347
22
C325
18p
L33
47nH
C356
470p
C329
470p
C350
0.33
C355
22
C351
0.001
C352
47p
C353
47p
C354
0.001
R363
4.7k
R364
8.2k
R344
15k
R346
10k
R347
100k
R343 150k
R318
220
R316
100
R319
180k
[USA]
C463
0.001
C462
0.001
C438
0.1
R345
10k
C436
1
C434
0.22
C406
0.01
C405
0.001
C392
0.001
C407 0.001
[IC-F1721 series]
[IC-F1821D]
Q36
2SC4116
[USA]
1
2
3
4
5
C435
0.001
C404
0.001
C383
0.3p
D35
1SS375
R303
10k
R317
270k
C382
0.001
C358
10
C333
2.2
C332
47p
R281
330
R294
10k
R293 1.5k
C322
0.001
C324
47p
C290
0.001
C328
0.001
C285
47p
C282
0.001
C280
10p
C281
0.01
R242
47
R251
100
R248
15k
R247
4.7k
R239
68
R238
10k
R243
220
R216
8.2k
R210
100
R237
100
R211
8.2k
C286
0.001
C279
0.001
C259
10p
Q22
2SC5107
C288
0.001
C287
10p
R246
1k
R245
10k
R208
120k
R209
100
C255
0.001
L22
617DB-1327=P3
L23
617DB-1327=P3
D16
HSB88WS
Q14
PMBFJ310
Q13
PMBFJ310
L17
4.7
µ
H
C107
0.1
C87
3p
R85 47
R86
1.5k
R105
470
C130
0.1
C133
100p
C134
0.001
C166
47p
C168
0.001
C163
100p
C164
82p
L18
1
µ
H
C228
0.01
C229
0.001
C230
0.01
R184
22
L19
10
µ
H
C245
2p
C269
0.001
C270
0.001
C271
0.001
C294
0.01
C247
0.001
C292
1
C293
0.001
C291
0.001
C302
0.001
R218
150k
R219
220k
R220
10k
R257
470
R252
100
L31
56nH
R258
270
R253
4.7
R254
100k
R255
10
C303
0.001
C304
47p
C295
0.001
Q24 3SK293
Q6
2SC4215
R151 100
C165
0.001
C199
0.001
C198
0.01
D10
1SS375
R177
1k
R277
220k
R256
18k
R278
4.7k
R280
10k
R279
470k
R283
100k
R282
100k
R284
10k
D31
UM9401F
D28
MA2S728
D27
MA77
C385
30p
L37
56nH
L36
68nH
L32
68nH
C298
22p
C297
0.1
C300
0.001
C296
0.1
C299
0.1
C330
0.1
C335
0.001
C336
0.001
C331
1.5p
C359
6p
Q26
2SK1829
D22 MA2S111
D25
DA221
D24
MA2S111
D23
HVC375B
D26
HVC375B
D17
HVC350B
D18
HVC350B
L28
56nH
C364
6p
C360
0.001
D20
MA77
Q21
2SC5107
C263
0.001
R217
8.2k
L29
82nH
L27
82nH
R215
8.2k
R213
100
C262
0.001
Q20
2SC5107
C167 0.001
C153
220p
C155
0.01
C241
0.1
C243
47p
C257
0.001
C289
1p
C284
390p
C377
470p
C378
0.001
C379
0.001
C380
0.001
C381
0.001
C390
0.001
C403
0.001
C433
0.001
D19
MA77
D41
MA2S728
FI5
NFM60R20T152
1
2
3
FI6 NFM60R20T152
1
2
3
FI7 NFM60R20T152
1
2
3
IC12
TA31136FN
9
10
11
12
13
14
15
16
L25
68nH
L35
47nH
L42
47nH
L43
47nH
L44
47nH
Q9
2SC4116
Q17
XP1214
1
2
3
4
5
Q18
DTC144EU
Q23
2SC3356
R127
2.2k
R194
10k
R314
27k
R341
27k
C361
0.001
C362
0.001
R241
4.7k
R276
JPW
R181
150k
R180
100
C201
0.001
C205
0.001
C200
0.01
R375
100
R376
150k
R155
2.2k
L40
47nH
C487
0.1
L12
67nH
C227
12p
C283
22p
C323
18p
L30
82nH
R214
220
C261
18p
L24
33nH
L26
33nH
R99
4.7k
Q10
2SC4215
C334
2p
C301
3p
C345
8p
C373
18p
C375
18p
C391
18p
C432
18p
L39
56nH
C384
8p
C258
10p
C197
33p
R195
270
R197
270
R196
18
C246
18p
C516
18p
C264
33p
R244
470
R422
470
L34
47nH
C326
22p
C517
22p
R383
390k
R182
10
C266
2.5p
C267
22p
C348
10p
C203
15p
R100
390k
C132
100p
C131
100p
R101
6.8k
R425 33k
R103
100k
R104
47k
R102
6.8k
R133
270
Q46
2SC4116
Q47
2SC4116
C188
33p
IC47
TC7S66FU
R179
1k
C224
33p
C225
22p
C156
10
FI4
FL-380
46.350 MHz
1
IN
2
OUT
3
GND
4
GND
5
6
IC29
S-AV32
[USA]
S-AV33
[EUR], [GEN]
1
IN
2
VG
G
3
VDD
4
OUT
R154
330
C204
2p
C202
2p
C231
0.001
C196
10p
C219
47p
R176
390
C191
15p
C189
7p
C265
10p
C349
6p
C321
18p
R250
82
R320
PRF18BC4710B1RB
[USA]
D21
RB886G
D68
RB886G
R295
3.9k
RSSI
T1
TMUT
T2
T2
RSSI
DET
SQL
RSSID
DFIL
NOIS
YGR
APC
AGC
RF AMP
MIX
IF AMP
IF
RX VCO
TX VCO
T8V
R8V
R8V
R8V
5V
T8V
T8V
R8V
8V
HV
FWD
REV
R259
270k
IC39
TA8225L
STBY
TJDET
NF2
IN+
PREGND
IN-
NF1
EMGDET
RIP
VCC1
OUT1
BS1
PW
-GND1
PW
-GND2
BS2
OUT2
VCC2
C468
220
C470
220
C443
100
C444
100
C471
1000
R367
1
R368
1
R351
68
R353
68
R350
1k
R355
33k
C448
0.001
R328
10k
C446
0.1
C442
47p
C412
0.1
R349
220k
R354
220k
R325
2.2k
C414
0.01
C469
0.001
IC34
TA75S01F
1
2
3
4
5
R327
100k
R352
3.3k
R366
3.3k
C447
3.3
C415
0.1
R326
33k
C413
0.01
R424
100k
C445
47
C472
0.047
C473
0.047
R329
100k
SIGNAL
HLC
H_OUT2
H_OUT1
H_GND
C495
47p
C496
47p
C497
47p
C505
47p
C499
47p
C500
47p
C501
47p
C503
47p
C504
47p
C508
47p
C509
47p
C498
47p
J11
R414 1k
R406 1k
R409 1k
R411 1k
R407 4.7
R410
4.7
R413 1k
R405 1k
R415 1k
R416 1k
R417 1k
C511
47p
C513
47p
H_OUT2
H_OUT1
H_OUT1
CPU5
MAIN CPU
IC23
HD64F2268TF
1
PM6/SEG31
2
PM5/SEG30
3
PM4/SEG29
4
PM3/SEG28
5
PM2/SEG27
6
PM1/SEG26
7
PM0/SEG25
8
PL7/SEG24
9
PL6/SEG23
10
PL5/SEG22
11
PL4/SEG21
12
CVCC
13
PL3/SEG20
14
VSS
15
PL2/SEG19
16
PL1/SEG18
17
PL0/SEG17
18
PK7/SEG16
19
PK6/SEG15
20
PK5/SEG14
21
PK4/SEG13
22
PK3/SEG12
23
PK2/SEG11
24
PK1/SEG10
25
PK0/SEG9
26
PJ7/WKP7/SEG8
27
PJ6/WKP6/SEG7
28
PJ5/WKP5/SEG6
29
PJ4/WKP4/SEG5
30
PJ3/WKP3/SEG4
31
PJ2/WKP2/SEG3
32
PJ1/WKP1/SEG2
33
PJ0/WKP0/SEG1
34
P10/TIOCA0
35
P11/TIOCB0
36
P12/TIOCC0/TCLKA
37
P13/TIOCD0/TCLKB
38
P14/TIOCA1/IRQ0
39
P15/TIOCB1/TCLKC
40
P16/TIOCA2/IRQ1
41
P17/TIOCB2/TCLKD
42
A
VSS
43
P97/AN9/D
A1
44
P96/AN8/D
A0
45
P47/AN7
46
P46/AN6
47
P45/AN5
48
P44/AN4
49
P43/AN3
50
P42/AN2
51
P41/AN1
52
P40/AN0
53
VREF
54
AVCC
55
PH7/TONED/TMCI4
56
MD1
57
OSC2
58
OSC1
59
RES
60
NMI
61
STBY
62
VCC
63
XTAL
64
VSS
65
EXTAL
66
FWE
67
MD2
68
P77/TXD2
69
P76/RXD2
70
P75/TMO3/SCK2
71
P74/TMO2
72
P73/TMO1
73
P72/TMO0
74
P71/TMRI23/TMCI23
75
P70/TMRI01/TMCI01
76
P30/TXD0
77
P31/RXD0
78
P32/SCK0/SD
A1/IRQ4
79
P33/TXD1/SCL1
80
P34/RXD1/SD
A0
81
P35/SCK1/SCL0/IRQ5
82
PF3/ADTRG/IRQ3
83
C2
84
C1
85
V3
86
V2
87
V1
88
PH3/COM4
89
PH2/COM3
90
PH1/COM2
91
PH0/COM1
92
PN7/SEG40
93
PN6/SEG39
94
PN5/SEG38
95
PN4/SEG37
96
PN3/SEG36
97
PN2/SEG35
98
PN1/SEG34
99
PN0/SEG33
100
PM7/SEG32
R261
100k
C248
0.1
C249
0.1
C250
0.1
R285
1k
C308
0.1
R264
100k
X5
CR-520
19.6608 MHz
R187
12k
R189
12k
R190
12k
R188
10
D15
MA77
C232
0.01
C233
33p
C234
7p
C235
22p
R191
1M
R186
100k
R185
100k
D14 DAN202K
Q15
DTA144EU
R287
1k
R288
1k
R198
100
CP17
R387
100k
R286
100k
R393
100k
R392
47k
IC46
S-80942CNMC
1
OUT
2
VDD
3
VSS
4
NC
5
CD
C515
0.027
R442
100k
R450
100k
UNLK
CDEC
SDEC
BEEP
SENC
DDST
NOIS
OPT3
OPT2
OPT1
MMUT
RMUT
LVIN
BA
TV
CSI
CSO
DDAC
DDSD
NWC
TMUT
TXC
PLST
DAST
DSDA
CCK
CENC0
CENC1
CENC2
XRTS
DUSE
CSFT
TEMP
CSFT
EPTT
PWR
PWON
POSW
PW
ON
ESCL
PMFM
ESD
A
ESDA
ESDA
ARXD
A
TXD
AFON
SCK
DTPD
PGI2
HORN
MFDA
HLC
DASW
PGI3
RSSI
PGO1
PTT
O
B
USY
PTTI
PGO2
MDIO
MSCK
PGI1
DIM
PA
PA
2
SSO
MTCK
NTXD
NRXD
MRDF
IGSW
FMDA
MDIR
MTDT
EXST
EXOE
CIRQ
XCTS
ARES
MD1
CCS
HANG
J10
IC26
HN58X24128FPI
1
A0 2
A1 3
A2 4
VSS
5
SDA
6
SCL
7
WP
8
VCC
R262
10k
R263
100k
C306
0.1
ESCL
ESCL
GND
GND
GND
CPU5
CPU5
CPU5
CPU5
CPU5
CPU5
GPS
1
2
3
4
5
6
5V
TEMP
LVIN
8V
CPORF
FINRF
5V
REF
MIX
IF
FIL
B
A
8V
CPU5
5V
AFO
VCC
MAIN UNIT
VOLTAGE LINE
TX LINE
RX LINE
Explanatory notes
Power OFF: 4.6 V
ON : 0 V
13.6 V
5.0 V
7.8 V
5.0 V
4.8 V
4.9 V
W 0.7 V
N 1.0 V
6.9 V
TX 0 V
RX 4.9 V
TX 1.6 V
RX 2.6 V
TX 5.0 V
RX 0.2 V
TX 7.9 V
RX 0V
TX 0 V
RX 7.7 V
TX 0.2 V
RX 0.3 V
TX 0 V
RX 5.6 V
TX 0 V
RX 3.9 V
TX 0 V
RX 6.2 V
TX 6.5 V
RX 0 V
TX 0 V
RX 2.8 V
TX 3.0 V
RX 0 V
TX 2.3 V
RX 0 V
6.7 V
6.3 V
7.0 V
TX 4.3 V
RX 0 V
TX 0 V
RX 4.3 V
11 - 4