Icom IC R8500 Service Manual Addendum page 275

SECTION 10 BLOCK DIAGRAM
• BLOCK DIAGRAM-1
0.1-0.5MHz
LPF
B1
B1
0.5-1.6MHz
LPF
ATT
B2
B2
1.6-2MHz
BPF
HPF
B3
B3
2-4MHz
BPF
B4
CHASSIS
B4
RL RL
CTRL CTRL
4-8MHz
-30MHz ANT1 Q16 Q15
BPF
2SK2036 2SK2036
B5
(50ohm)
-30MHz ANT2 B5
8-11MHz
(500ohm)
BPF
B6
ANT
SW B6
11-15MHz
BPF
B7
B7
LPF ATT
15-22MHz
20dB
BPF
B8
B8
22-30MHz
BPF
30MHz-2GHz ANT
B9
RF-C UNIT
B9
PLL-B UNIT
VCO1 V1
SW
Q10 RN2427 Pdat
Q11 DTC114EU Pck
STDA
VCO2 V2
SW
DDS
Q12 RN2427
VCO1
Q36 DTC114EU
VCO2
VCO3
FL1
SW VCO4
HF
VU
Q54 DTC144EU
FIL3
Q55 DTA144EU
FIL4
FL2
SW
Q52 DTC144EU
Q53 DTA144EU
FIL3 FL3
SW
Q21 DTC144EU
Q22 DTA144EU
FIL4 FL4
SW
Q24 DTC144EU
Q25 DTA144EU
VU V1L
SW
Q13 DTC144EU D+5
+5
Q37 DTA144EU REG
X1
HF H1L IC24
SW
TA7805F
CR-452
TCXO
Q46 DTC144EU +5 13.8
+5
Q47 RN2424 REG
H2L IC16
SW
TA7805F
OPTION
Q49 DTC144EU +8 +8
CR-293
Q50 RN2424 REG
IC17
MC7808
+16 +24
+16
REG
Q34 2SC3661
D20 MA8160
Q11 Q17
RN2427 RN2427
HF8
SW
CTRL SW CTRL
SW
HF13
Q12 Q10
Q13
RN2427 XP1213
XP1213
HF5 B9 SW
Q14
DTA114EU
PRFF
CTRL
PRFO
Q5
SW
DTA114EU
SW
Q4 FI1
Q6,Q7
RN2427 48.8MHz
2SK2171
LPF
THROUGH
D16
1SV237
RF
ATT
AMP
Q1,Q2
2SK2171
Q3
XN4601
AGC
CTRL
IC3
SC-1246
VCO
CHARG PLL
LPF BUFF LPF
PUMP IC
Q2
Q44 2SA1576
Q3
2SK210
Q45 2SC4081
2SC4081
FL1
D/A BPF AMP
IC4
TC7S04F
HF
LPF ATT
IC10
Q14 2SK536
MC145190
Q15 2SC3661
PLL
AMP 1/2 LPF
IC
IC7
TC7S04F IC11
HD74LS90FP Pdat
Pck
STP2
IC21
Pdat
TC7S04F
Pck
IC13
IC19
STDB
SC-1287
AMP
TC7S04F
AMP DDS
IC15
IC18
SC-1287
TC7S04F
AMP DDS
Pdat
Pck
STDB
10 - 1
CONV-B UNIT
Q6
Q5 Mdat
Mck
Q4
STBC
Q3
OE
Q2
Q1
IC4
IC5
BU4094
TD62783
B1
B2
B3
Mdat
B4 Q1-Q8
McK
B5
STBC
B6 OE
B7
(FROM MAIN)
B8
IC3 13.8
BU4094
+5
+8
Q8
3SK131
D18
ND433G
HFIF 10.7MHz
IF
BPF LPF
AMP
(TO MAIN) Q4
DTC144EU
H2LO 38.1MHz
LO
ATT LPF ATT
AMP (FROM PLL)
IC1
uPC2710
H1LO 48.9-78.79999MHz
LO
BPF ATT
AMP (FROM PLL)
IC2
uPC2710
AGC (FROM MAIN)
PAKA
Q41 DTC114EU
CTRL VCO-A BOARD Q2
Q40 DTA144EU
V1
2SC4835
VCO1
Pdat
Pck
BUFF
IC20
STP1
TC4W66F
Q1 V2
SW
2SK1577
IC5 Q4
MC145190 2SC4835
VCO2
CHARG
LPF BUFF
PUMP
Q3
Q42 2SC4081
2SK1577
Q43 2SA1576
VCO1-f=383.35-510.399995MHz
Q38 FMS2A
VCO2-f=510.40-645.84995MHz
Q39 FMW2
LPF AMP
IC6
uPC1688
BUFF
H2L
SW LCT(TO MAIN)
IC8b
NJM4558
Q7,Q8 DTC144EU
VCO3-f=256.0MHz/304.8MHz
Q9 DTA144EU
VCO4-f=768.0MHz
VCO3 VCO-B BOARD 304.6MHz
V1L
Q1 VCO3 IC12
SW
2SC4835 uPC1688
Q2 DTC114EU
VCO4 ATT AMP
Q3
SW
2SC4835
VCO4
Q4 DTC114EU
Q28
2SC4081
D/A HPF LPF BUFF
Q31
2SC4081
D/A HPF LPF BUFF
DATA
CTRL
STP1,STP2 Pdat
STDA,STDB Pck
IC1,IC2
PAKA STDB
BU4094
POE
Pdat
Pck
CTRL
Q6
DTC144EU
RL Q2 Q3
XP1213 RN2427
CTRL
1G5V
5M SW
SW SW
Q5 Q14 Q10
RN2427 RN2427 DTA114EU
ANT
SW
30-1024.99999MHz
1G SW
HPF
RX
SW
IC1
GN1017
SHIFT
1025-1999.99999MHz LPF
RF
SW
ATT
AMP
IC2
5MXF25-7
IC3
uPC2708
Q13
2SC4081
RF
HPF ATT
AMP
RIPPLE
ATT
FIL
(FROM MAIN)
Mdat
Mck
STBE 1G
IC4
MC145190
VCO
PLL
LPF LPF ATT AMP
IC
IC6
MQE001-1016
IC7
uPC2708
Rx-f= 0.1-29.99999MHz
LO-f=46.9-78.79999MHz
1/8 BUFF LPF ATT
ATT
IC22 Q48
MB511PF 2SC4081
HPF LPF ATT
HF=x1
VU=x2
Rx-f= 30- 499.99999MHz
FL1
IC9 = 1200-1499.99999MHz
uPC2709 Lo-f=808.7-1278.69999MHz
Rx-f= 500-1199.99999MHz
ATT HPF LPF = 1500-1999.99999MHz
Lo-f=766.7-1291.69999MHz
391.2-630.399992MHz
FL2
IC23 Q51
MB511PF 2SC4081
H2LO
1/8 BUFF LPF ATT
(TO RF-A)
Rx-f= 30- 499.99999MHz
Rx-f=0.1-29.99999MHz
=1200-1499.99999MHz
Lo-f=38.1MHz
Lo-f= 768.0MHz
Rx-f= 500-1199.99999MHz
=1500-1999.99999MHz
ATT HPF LPF
Lo-f= 258.0MHz
256.O/768.0MHz 256.0MHz
FL3 ATT
HPF LPF
768.0MHz
FL4
3LO
LPF
Lo-f=10.245MHz
IF-SHIFT=10.2435-10.2465MHz
BFO
LPF
USB=456.5kHz LSB=453.5kHz
CW =454.2kHz AM =455.0kHz
IF-SHIFT=452.0-456.0kHz
(100Hz-STEP)
IC11 IC10
TD62783 BU4094
1GON
2ATF Mdat
Q1-Q7
Mck
2ATN
STBB
1ATF
OE
1ATN
(FROM MAIN)
5MON
+24
5MOF
+5
+8
CTRL
Q7
Q11 Q12
XP1213
2SC4835 2SC4835
MUTE MUTE
2ATF 1ATF
RF
A
THROUGH THROUGH
ATT ATT
20dB 10dB
2ATN 1ATN
5M
LPF AMP ATT
0.5GHz IC9
uPC2709
Rx-f=1025-1199.99999MHz
Lo-f=0.50GHz
LPF
Rx-f=1200-1989.99999MHz
1.00/1.01GHz
Lo-f=1.00GHz
Rx-f=1990-1999.99999MHz
IC8
Lo-f=1.01GHz
uPB584G
0.5GHz
LPF 1/2
5M
1G
1.00/1.01GHz
B
H1LO
(TO RF-A)
Q3
DTA114EU
MIXV AMP
SW
V1LO
C
D
(TO RF-B)
Q2
3SK131
IF E
AMP
1LLV(L1AD)
F
FI3 16kHz
G
BPF
Q58
XP4311
/WF8
SW
IC5
V2LO UPC1658
NB NB
(TO MIX)
AMP AMP
Q9
2SK682
D10
Q11
1SS375
2SK862
NB NB H
AMP DET
Q10
XP4601
AGC
CTRL
I
J
K
Pdat
Pck
PSTB
POE