1Stavco Board; 1Stbvco Board; 2Ndcvco Board; 2Nddvco Board - Icom IC-R20 Service Manual

SECTION 10

BLOCK DIAGRAM

ANTENNA
0.1500 – 3304.9999 MHz
Explanatory notes
RF UNIT
VOLTAGE LINE
RX LINE
0.4950–1.6200 MHz
D68 ANT LEVEL
BAR
LIMIT
1SV172 ANT TUNE CONV.
D100: SVC347 Q513: XP4601
ATT-CONT.
ANT
ATT
SW
Q508: XP4312 Q510: UMD6
Q507: 2SC5008 Q506: UNR9110J
D64, D67, D70:
D69: 1SV308
1SV308
D169–D170: MA2S728 1SV308
D76: MA2S077
D65–D66, D73, D74
MF
BAND BAND
LPF LPF
SW SW
HF-L
BPF
HF-H
BPF
Q14: 2SC5006
D162: MA2S728
A_VHF3V
D166: MA2S728
PRE RF
AMP AMP
Q550: FH102
A-AGC
D149: MA2S728
D148: MA2S728
B_VHF3V
RF
AMP
Q549: 2SC5006
D152: MA2S728
D161: MA2S728
B-AGC
D75:1SV308
Q552:UNR9113J
30–300 MHz
D101:MA2S077
ANT
HPF BPF
SW
Q35:2SC5006
A_UHF3V
D159:MA2S728
D168:MA2S728
D13: 1SV308
BAND PRE RF
LPF
D3: 1SV308
AMP AMP
SW
D11: 1SV308
Q551: µPA805T
A-AGC
D150: MA2S728
D151: MA2S728
B_VHF3V
RF
AMP
Q548: 2SC5006
D158: MA2S728
D153: MA2S728 B-AGC
B_800M3V
800 MHz
Q24: 2SC5008
RF
BPF
AMP
D173: HVC375B
D174: HVC375B B-AGC
B_G3V
Q26: 2SC5624
D155: MA2S728
1GHz
D156: MA2S728
RF
BPF
AMP
B-AGC
Q5: XP1113
BAND
SW
D2: 1SV308
BAND RF BAND
HPF
AMP
SW SW
MIX
IC2: IC3: µPC2757TB D8: 1SV308
D1: 1SV308
µPC2749TB
D7: 1SV308
DOWNCONV
BOARD HPF
Doubler
B_R3V
RECORDING LINE
RF
PLAYBACK LINE AMP
IC18:
µPC2746TB
VP
A-TRAC
HF3V
BAND Q12: 2SC5277 IC3: MB15T61UL
SELECT
OSC
PLL
BUFF
D178: 1SS400
IC
Q504: XP1110
1–4B3V
HF3V
Q505: 2SC4226
Q7: 2SC4117
D164: MA2S728
Q6: 2SK880
D163: MA2S728
RF
VCO LOOP
AMP
3V FIL
Q10–Q11:
XP1113
A-AGC
A-VHF

1STBVCO BOARD

BPF
D1–D2: HVC350B
D36: 1SV308
D32: 1SV308
D143: 1SV308
B-VHF D147: 1SV308
BAND
BPF
SW
D145–D146: HVC350B
300M3V
A_R3V
Q36:2SC5006
D160:MA2S728
D167:MA2S728
RF RF
AMP AMP
IC19
µPC2746TB
A-AGC
A-UHF
BAND
BPF
SW
D4–D5: D72: 1SV308
HVC350B D29: 1SV308
D25: 1SV308
IC3: MB15T61
Q13: 2SC5227
D34: 1SV308
B-UHF OSC
BUFF
BPF
1–4A3V
HVC350B
Q7:2SC4117
D141 D142
Q6:2SK880
VCO
3V
Q11, Q12:
BPF
XP1113
D176:HVC375B
D175:HVC375B
IC4: MB15B03SL

1STAVCO BOARD

OSC
LO
PLL
BUFF BUFF
SELCT
IC
Q2: 2SC5006 Q6: 2SC5277
VCO
BAND
BUFF LPF
SW
D3: 1SV245
D6: 1SV308
Q4: 2SC5624
Q1: 2SC5006
D5: 1SV308
1001.0000/2002.0000 MHz
B_R3V 266.7 MHz B_R3V B MODEC 19.65 MHz
FI1
1ST 2ND FI7
EFCH266MKQP1
MIXER MIXER FL-293
MODE XTAL
BRF
SW BPF
IC16:
IC15:
D130: MA2S077 AM/NFM
B 1ST µPC2757TB
µPC2757TB
D131: MA2S077
B 2ND IF FILTER
IF FILTER
LO
LPF
AMP
LO AMP
WFM
Q9: 2SC5231
IC2: µPC2746TB
Q8: 2SC5231
BUFF BUFF
1–4B3V
D1:1SV245 Q4: 2SC4617
1B3V
1BVCO D7–D10:
Q1:2SC5006 1SV308 247.0500/286.3500 MHz
D2:1SV245
LO
SW
863.3000– VCO
1099.6999MHz Q1:FH102
2B3V D1:HVC350B
2BVCO IC1: MB15E03SL
683.3000–866.6999 MHz
D3:HVC417C
Q2:2SC5006
3B3V
3BVCO
566.3000–686.6999 MHz
D4:HVC417C
OSC
Q3:2SC5006 BUFF
4B3V
Q3: 2SC5277
4BVCO
2NDDVCO
384.7000–441.6999 MHz
D5:HVC417C
Q4, Q5:2SC5006
BOARD
+3S
19.2 MHz
OSC
REF
OSC
Q556: 2SC4617 X1: CR-593 D171: HVC350B
429.1 MHz
19.65 MHz
A_R3V A_R3V AMODEC
FI4
FI3
EFCH429MKQP1
FL-293
XTAL
MODE
BRF
BPF
SW
1ST Mix
2ND MIXER
IC1 D58: MA2S077 AM/NFM/SSB
A 1ST IF FILTER IC10
µPC2757TB
µPC2757TB D59: MA2S077 A 2ND IF FILTER
LPF
Q9
2SC5231 WFM
LO
AMP
IC2: µPC2746TB
Q8: 2SC5231
PLL
BUFF BUFF
IC
409.4500/
1–3A3V
1AVCO
448.7500 MHz
Q1: 2SC5006 1A3V
D2: 1SV245
D1: 1SV245
VCO
LOOP LO
Q1: FH102
SW
FIL
D1: 1SV314
849.1000–899.0999 MHz
IC1: MB15E03SL
D7–D9:
1SV308
2AVCO
2A3V
D3:HVC417C
Q2:2SC5006
Q3: 2SC5277
604.1000–849.0999 MHz OSC
BUFF
3AVCO 3A3V
D4: HVC417C
Q3: 2SC5006
2NDCVCO
429.2500–604.0999 MHz
BOARD
B_AM3V B_800M3V B_G3V
Q546: XP4312 Q503: XP1113 Q503: XP1113
+3 +3
+3
REG REG
REG
DA/EXPND
IC22: CD4094
IC20, IC14: M62366
B MODEC B_R3V B_R3V B MODEC
Q542 IC17: TA31136FN
2SC5006
B-MIXOUT
MODE
MODE IF
FM IF-IC
SW AMP SW
D134:1SS400
D132: MA2S077 B-AGC
D135:1SS400
D133: MA2S077
B_R3V B-IFIN
3RD LO AMP
OSC 19.2 MHz
LO
WIDEFM
AMP CONT.
Q555
Q543
2SC5006
UNR9113J
B_AM3V
Q544
A_R3V XP6501
IF
AMP
RIPPLE
FIL
LOOP
FIL
DET OUT
AF
SW
BMODEC
B AM FM
Q553 IC21: CD4066
MODE
PLL B WFMC
XP1113 CONT.
IC
Q525: XP6501
Q521: 2SC4617
B_R3V
A_R3V
OSC
19.2 MHz
REF LO
AMP
CONT.
Q540: 2SC5006
3RD LO AMP
A_R3V
AMODEC
AMODEC
A_R3V
IC2: TA31136FN
Q5: 2SC5006
A-MIXOUT
IF
MODE
FM IF IC
SW AMP
D60:MA2S077
D108:1SS400
D61:MA2S077
A-AGC D109:1SS400
D110:1SS400
AMODEC
A-IFIN
A_R3V
Q519: UNR9113J
MODE WIDEFM
Q534: XP1113
SSB3V
CONT.
CONT.
D119: DAP222
Q41: UNR9113J
A_R3V
A WFMC A NFMC
Q1
SSBC
RIPPLE
XP6501
FIL
IF
Q4: 2SC4617 AMP
LOOP
FIL
3rd IF
AMP
PLL
Q531: 2SC4617
IC
A_DETFM
A_DETSSB
BFO
RFO SSBAF
AMP
AMP
D115: RB876W
Q532
Q530:
D116: RB876W 2SK1069
2SC4617
B_UHF3V B_VHF3V A_UHF3V A_VHF3V 300M3V
Q554: XP1113 Q554: XP1113 Q502: XP1113 Q502: XP1113 Q501: UNR9113J
+3 +3 +3 +3 +3
REG REG REG REG REG
10 - 1
B_DET
0.450 MHz B MODEC
FI8
A_DET
CFWM450E
CERAMIC MODE
BPF SW
AM/NFM
D136: 1SS400
B 3RD IF FILTER
D137: 1SS400
LPF
WFM
B_AM3V B_AM3V
Q545 ×1/2
XP6501
AM
AGC B-AGC
DET
Q545 ×1/2
XP6501
AM DET
ANL
Q547:UNR9213J
D139:MA2S728
B_DET
NB3V NB3V NB3V
NB
MUTE
DET
AMP
SW
Q523: 2SC4617 Q528: 2SC5006
Q524: 2SC4617
NB3V Q526: UNR9113J
AGC
Q522: 2SC4617
FI6: CFWM450K3
CERAMIC
BPF
SSB/CW
AMODEC
0.450 MHz
A 3RD IF FILTER
FI2: CFWM450E
MODE CERAMIC
MODE
SW BPF
SW
AM/NFM
D113: 1SS400
D112: 1SS400
D111: 1SS400
LPF
WFM
Q4 ×1/2 Q4 ×1/2
XP6501 XP6501
AM
AGC A-AGC
DET
A_DET
AF
SW A_DETAM
ANL
Q529: UNR9213J
D114: MA2S728
IC12: CD4066
NB3V HF3V
Q527: UNR9113J Q509: UNR9113J
+3 +3
REG REG
A_R3V
B_R3V