Voltage Diagram; Rf Unit - Icom IC-R20 Service Manual

SECTION 11

VOLTAGE DIAGRAM

11-1 RF UNIT

W1 W2
R234
820
D69 R232
1SV308
3.3k
R233
C540
0.1 820
CP5
R247
2.7
Q507
1 blue 2SC5008
B
EP2
2 white
W
BAR ANTENNA
3 red
0.4950 – 1.6200 MHz
R
4 green
G
D66
1SV308
CP8
D65
C912
C872 1SV308
0.1
0.1
D73
R538
1SV308
JPW
C513
100p
CP7
D74
R246 1SV308
C567
220k
0.1
C859
0.001
R243
100k
C853
D100
15p
SVC347
L125
47nH
C852
27p
CP6
L124
56nH
C851
27p
R496
4.7k
L123
47nH
C860
0.001
VP
C854
4 5 6
9p
L126
Q513 C855
18nH
47p
XP4601
3 2 1
A_TRAC
C856
7p
L127 C857
R329 18nH 100p
100k
R330
C669
15k
0.001
A_TRAC
ANTENNA
0.1500 – 3304.9999 MHz
C858
C546
12p
C541 C542
0.1
0.1 0.1
D3 C888
CP3
1SV308 0.001
D68
1SV172
R511
2.2k
470 MHz
2.9V
HJ10
C54
RFIN
RFIN 0.001
8
GND
7
OSC OSC
6
PLLCK
PLLCK
5
to DOWNCONV
PLLDATA PLLDATA
4
BOARD J1
PLLESTB PLLESTB
C32
3 D11
1SV308 0.001
2
IF_OUT
1
R522
C925 C924 C923
10p 10p 10p 100k
DOWN
C923 – C925
CONV
R510 except D13
2.2k [SEA], [EXP] 1SV308
BOARD
R99 R98
HJ11
1k 2.2k
1
1
2 1GLO
2
3 2GLO C55
3
0.001
to DOWNCONV 4 DOWN_CONV
4
BOARD J2
5 +3V
5
6
6
C911
R534 100
2.7
+3S
C566
0.01
D170 D169
R327
MA2S728 MA2S728
100
C667 C545
R235 0.01
0.01
1k R238
100k
C570 C563
0.001 0.001
6 5 4
ATT-ON
Q508
0V
R237
XP4312 C891
2.7k
0.01
1 2 3
C543 R236
0.001 10k
C558 C544 C674
0.001 0.001 47p
R225 1k
L81 L82
0.33µH
0.27µH
R222
2.2k
C511 C512 R488 C842
C515 330 0.001
36p 10p
C514
120p Q550
180p
FH102
VHF PRE-AMP 4 3
C416 L128 C13 C841
27p 0.1µH
27p 18p
5 2
C843 R486
6 1
C12
8p 100
47p
R484 L121
R531
L70 22k 0.18µH
100k
R485
0.10µH
4.7k
C840
C839
0.001
0.001
R216
2.2k
D148
MA2S728
C897
C548 145 MHz
0.001 0.001
2.6V
D149
MA2S728
30 – 300 MHz
Q36
C142
0.001
2SC5006
D75 L9 L10 C665 C43 L133
1SV308 33nH 22nH 100p 100p 56nH
R105
C42
68 R108
C666
3.5p
390p R18 2.2k
15k
C141
R494
C40 C41 R6
L92 L41
4.7k 0.01
15p 5p
120 0.1µH
0.39µH
D101
C861
MA2S077 0.001
Q552 R106
C44
47k
0.01
UNR9113J
D167 MA2S728
ANTSW R495 4.7k
C673
0.001
D160 MA2S728
ANTSW
R335 EAR
51 MHz
100k
2.9V
C676
A_ATTC
22p
ANTSW
EAR
A_TRAC
Q551
UHF PRE-AMP C847
R491
UPA805T 0.001
330
L3 L4 L5 L39
4 3
15nH 22nH 15nH 39nH
C845
C848
R492
8p
5
2 3p 150
C218
1p
6 1
R489
L122
22k
R490
47nH
R493
C22 C23 4.7k
7p 5p 433 MHz 150
C846
C844
2.6V
0.001
0.001
R239
2.2k
C901
0.001 D157 MA2S728
D154 MA2S728
C887 0.001
B BAND 800M
R102
R95
2.2k
R101 R100 C214 L131 L132
2.2k
12k 0.001 3.9nH
47k 3.9nH
C145
C886
L130 0.001 Q24
D174
0.001 D32
3.9nH
HVC375B
2SC5008 1SV308
D176
HVC375B
L129 C138
R93 R523
D173
D175
3.9nH 470p 120 100k R524
HVC375B
HVC375B
100k
C147 D36
C895 Q26
2.5p 1SV308
470p
2SC5624
C45 C46 C49 L13
470p 3p 3p 5.6nH
L44
R112
C5
L43 4.7nH
2.2k
470p 1.5nH
C47 C48
6p 6p
C50
R20
C51 R19 C52
1p
L11 L12 2.5p 47k 330
470p C148 C414
15nH 10nH 470p 0.001
R110 12k
B_BAND 1G
D156
MA2S728
1295 MHz
2.9V
D155
MA2S728
C568
R241 3 4 R245
47p
2.2k
22k
R240 2 5
1k
1 6
Q506
C536
C569 UNR9110J
Q510 0.1
D76 0.1
MA2S077 UMD6
R229
L90
47k 100µH
L88 L89
MF
D67
5.6µH
10µH
1SV308
C533 C534
C657
C658
100p C535
0.0015 150p R230
390p
0.0012
L86 L87 10k
C522 C523 C524 D70 C537
0.0015 0.68µH 1µH 1SV308 0.1
0.0015 0.01
C525 C526
0.0047
0.012
C527 C528
R228
L91 L85
47p 10p
R226
100
3.9µH 3.9µH
2.2k C529 C530 HF L C531
150p 270p 100p
D164
MA2S728
D163
C516 C517 D64
C520 C518
C519
220p 100p MA2S728
220p 1SV308
0.0018 C532
0.0047
0.1
HF H R224
R223
5 1
3.3k
L83 L84
2.2k
0.47µH 0.68µH
2
4 3
C521 C560
0.1 Q504 0.001
XP1110
R78
330 Q14
R539 C14 C15 C16 C121
2SC5006
15
C837 0.001 1p 0.001 0.001
100p
L28
D1 R10 L1 D2 R11
R81
68nH 47k 47nH HVC350B 47k
HVC350B
2.2k
C69
R9
0.001
R487
120k
145 MHz
100 C408
2.9V
R8 C233 0.001
15k 0.001
A-BAND VHF
C900
0.001
D166 MA2S728
D162 MA2S728
R478
330
Q549
R540 C832 C833 C834 C835
2SC5006
15
0.001 1p 0.001 0.001
C838
D145 R481 L120 R483
100p D146
L119 HVC350B 47k 47nH HVC350B 47k
68nH
C898 C827
0.001
0.001 R476
120k
R479
C828
C836
15k
0.001 0.001
B-BAND VHF
C899 D152 MA2S728
0.001
D161 MA2S728
D34 1SV308
A_ATTC
ANTSW
EAR
A_TRAC
R15 C30 R16
Q35
47k 0.001 47k
2SC5006
C28 C59 C58 C136
C849 0.001 2p 0.001 7p
100p
L61 D4 L60 D5
R14
6.8nH HVC350B 6.8nH HVC350B
68k
R88 C134 C27
0.001
330 0.001
C850
100p
R13 15k
D150 A-BAND UHF C150
C410
MA2S728
0.001 0.001
B_ATTC
D168 MA2S728
AGC
D159 MA2S728
B_800M3V
Q548
R473 C815
2SC5006 0.001
47k
C812 C814 C816
0.001 2p 0.001
R469
L112 D141 L113
68k
6.8nH HVC350B 6.8nH
R472 C811 C809
330 0.001
0.001
D151
R471
MA2S728
B_UHF3V
15k
C807 C808
B BAND UHF
0.001 0.001
433 MHz
2.9V
D153 MA2S728
B_ATTC
AGC
D158 MA2S728
C868
B_ATTC 0.001
B_800M3V
B_TRAC
B_ATTC
B_G3V
AGC
B_R3V
Explanatory notes
IC15
µPC2757TB
VOLTAGE LINE
1
RFI
RX LINE
2
GND
3
LO
C746
B_R3V 3.5p
R423
ATT
15
A_R3V
C747
ANTSW
0.001
C571
0.001
B1C B BAND RF IN
HFC
C539
Q509 C562
0.1
0.001
UNR9113J
D72
1SV308 AGC
AGC
B_R3V
Q505
R533
C921
2SC4226
10
0.001
C538
R501
0.1
4.7k
A_TRAC
5 MHz
2.9V
B2C
D178
1SS400
B3C
300M3V
C561
0.001
A_VHF3V
D25
1SV308
A_UHF3V
B_VHF3V
A_TRAC
A_VHF3V
B_UHF3V
A_ATTC
B_G3V
D147
1SV308
B_800M3V
R482
2.2k
B_R3V
ANTSW
A_R3V
B_TRAC
B_VHF3V
AGC
A_ATTC
300M3V
EAR EAR
A_TRAC
D29
1SV308
R91
2.2k
A_UHF3V
A_ATTC A_R3V
B_TRAC
L56
6.8nH
R474
47k
D143
C817
1DV308 C153
7p
0.1
D142 R475
HVC350B 2.2k
IC1
µPC2757TB
1
RFI IFO
2
GND VCC
B_UHF3V 3
LO PS
C206 C70
3.5p 0.001
R220
AGC
15
B_ATTC
R4
330
B_800M3V B_800M3V
B_TRAC B_TRAC
B_G3V B_G3V
AGC
11 - 1
433 MHz
3.0V
B_R3V
C71
3p
IC16
6
IFO µPC2757TB
IFO16
5
FI1 EFCH266MKQP1 C436
VCC
4
PS 3p
1 RFI 6
I O IFO
2 GND 5
C748 VCC
3 LO 4
PS
0.001
C750
0.001
L74
L15
C749
47nH 47nH
L101 0.001
CP18
6.8nH
D_VCO OUT
D_VCO OUT
B_VCO OUT
B_VCO OUT
B_RXV
C919
0.001
ATT
AGC
R497 220
C910 C865 R499
82
100 0.001
3 4
GND OUT
2 5
GND GND
1 6
IN VCC
R498 R500
C866 100 82
C864
IC18
0.001
0.1
µPC2746TB
433 MHz
B BAND RF AMP
1.9V
A_TRAC
A_R3V
A
Q501
UNR9113J
A_300MC
Q502
XP1113
5 1 A_VHFC
2
3 A_UHFC
4
C503 0.001
Q554
XP1113
4 3
B_VHFC
C862 0.001
2
5 1
B_UHFC
C863 0.001
B_R3V
Q503
XP1113
5 1
B_GC
C504 0.001
2
4 3
B_800MC
C505 0.001
ANTSW
A_R3V
R323 220
B_TRAC
B_TRAC
145 MHz
2.0V
A_ATTC
A_ATTC
IC19
µPC2746TB
C663 R325
0.1 82
3 4
GND OUT
C662
2 5
0.1 GND GND
1 6
IN VCC
R324 R326
C664
R231 100 82
0.1
4.7k
A BAND RF AMP
IFO10
A_R3V
145 MHz
C435
C677 3.0V
0.001
2p
6
IC10
5 L94 C678 C683
µPC2757TB
FI4 EFCH429MKQP1
4 33nH
0.001 0.001
O
I
1 6
RFI IFO
2 5
GND VCC
3 4
LO PS
L95
15nH
L93
R221 C432
22nH C679
330 0.001
0.001
A-AGC
B