Icom IC R8500 Service Manual Addendum page 276

• BLOCK DIAGRAM-2
RF-D UNIT
F1 F3
F2 F4
BPF1 BPF3
SW SW
BPF2 BPF4
Q6 XP1213 Q8 XP1213
Q7 XN1114 Q9 XN1114
Q5 RL
XP1213 CTRL
30-1025MHz
BPF
500-1025MHz
RF
A BPF
4
RX
SW
Q4
30-90MHz
BPF
1
BPF1 Q1
90-250MHz
BPF
2
BPF2 Q2
250-500MHz
BPF
3
BPF3 Q3
Q1-Q4 3SK228
B
Q1
2SC4081
HFIF
LPF ATT BUFF LPF
(FROM RF-A)
C
D
CDAC10.7MC4-A
Q4 /WF8
X1
3SK131 FI1 FI2 10.7MHz
230kHz 230kHz
E IF
BPF BPF FM IC
AMP
IC2 MC3356
F
OPTION
Q15
O.5kHz
3SK131 FL52A
G
AMP
FIL0
IC6
Q14 2SC1081 FI5 6kHz FI6 6kHz
UPC1037
NB
BPF BPF
SW
FIL2
FI7 15kHz FI8 15kHz
BPF BPF
Q12 2SC4081
Q13 XP4311
FIL3
AMP
H NB
FI4 2.2kHz
CTRL
BPF
FIL1
I
J
K
CHASSIS
J14 IC17 TA7805F
P2
+5
1 REG
2
REG IC23 TA7808S
3
4 POW 13.8 +8
IC22 PQ30RV31
SW REG
FRONT UNIT Q50 2SC4081 IC24 TA7808F
L+5
HV1 +5 +8
REG REG
LHV1
HV2
IC38 TA7805F
LHV2
13.8
(POWER SW)
MIX-A UNIT
LVDA
+8
+24
-8
SW
IC2a,b NJM2902V CTRL
(FROM MAIN)
TUN MT5V
Q2 XP1213
IC1b NJM2904M
CTRL Q3 XN1114
Q10 DTC144EU
FIL
IC2c,d NJM2902V
AGC AGC
SW
Q11,12 2SK1069
BUFF
TUN
IC1a NJM2904M
IC4
CTRL
GN2011
LPF ATT
30-500MHz
BPF
RX
ATT
SW
F1M V1IF
F2M
RF
ATT BPF
AMP
500-1025MHz
IC3
*PC2708
TUN
CTRL
IC7a
NJM2904M
LO V1LO V2LO
BPF ATT ATT
AMP
IC6 (FROM PLL) (FROM PLL)
*PC2709
768.0MHz
256.0MHz
IC32b
(TO RF-A,B)
NJM2904
AGC AGC
BUFF
WFM
AGC
CTRL
Q6
2SC4081
IC9b
SW
NJM4558
Q61
DTC144EU
AMP
Q59,Q74
DTC144EU
FIL2
SW
AGC
CTRL
AGC
DET
Q20 DTC144EU
Q21,Q23 2SA1586
D20
Q26 XP1213
Q25 DTA114EU
1SS375
CDBC455CX16 Q60 DTC144EU
Q27 2SC4081
X2
455kHz
AGC SHIFT
SW SW
AMP FM IC
HPF
Q54
IC8 MC3372
2SC4081
IC32a
IC19 BU4066
NJM2904
Q18
AF WF
Q47 2SC4081
2SC4081
AF FM Q46 DTA114EU
AM AF AM SQL GATE
AMP BUFF
DET
AF SB
Q16 Q17
D15
3SK131 3SK131
1SS375
DET IC7
*PC1037
USB 456.5kHz
LSB 453.5kHz
CW 454.2kHz AM
CENT
AM 455kHz
AM8
IC40 TC74HC86
BF0 L1AD(CPU)
IC41 TC74HC74
Q65 2SK882
Q66,Q67 2SC4081
Q68 DTC144EU
Q69 XP4311
+5
IC25 AN78L24M
+8 +24 +24
REG
Q51,52 2SC2873
D39-42 1SS272 IC26 AN79LO8M
-8 -8
DC-DC
REG
IC3 NJM2902V
Q1 DTC144EU
RF FIL FILS
SW
Q4,Q5
F2M
2SC4835
F1M (TO RF-B)
MUTE
-8
+8
(FROM MAIN)
MI5V
[METER]
IC1 MAIN
778.7MHz
DIAL
CB501M 10.7MHz
V2IF
BPF LPF LPF
BPF1
266.7MHz
BPF
768.0MHz
BPF2
LPF
LPF1
IC2
*PC2710
256.0MHz
LO
ATT ATT LPF
AMP
LPF2
IC9a
IC43 TC4W53F
NJM4558
Q75 DTC144EU
13.8
AMP CTRL IFBK
(TO RF-B)
X3
NOISE
AMP 9.8304MHz
DET
IC33
D16
IC4a
HD6433334YL02F
1SS375
NJM2904
SMAD
NOAD
IC4b
AM8
NJM2904 CMAD
L1AD
MAIN
LCT
AMP (FROM PLL) CPU
CENT STOP
DET VSC
Q7
VBSY
IC10 NJM2904
XP1213 IC13 NJM2904
IC11 *PD4001
Q31,Q70 DTC144EU
IC12 NJM2904
Q30 DTC144EU
VSC RXD
AMP
CTRL TXD
Q62
2SC4081
CTRL IFBK
Q28 2SJ144
Q29 XP1213
IC29 BU4053
IC30 BU4053
IC31 NJM2902
IC39 X9C503
APF CTRL
Q54 XP1213 /INC
ISW1
U/D
SW
ISW2
Q48
2SC4081
BEEP
BUFF
VOIC
OPTION
+5
UT-102
VOICE Mdat
+5
UNIT Mck
VSTB
DS2-5 IC5 PQ20VZ51
DS1 HRS4150A Q7 DTC144EU
LAMP 13.8
LCD
CTRL
(FROM MAIN)
IC4 S-8054ALB
Q1 2SC4081
IC3a *PD40308G
IC2
D1 1SS355
SED1522
(FROM MAIN)
DDT L+5
RESET
DRIVER
X1
9.8304MHz
ME1
DIM
MFTV
MATRIX SW IN
IC3c IC3d
S2 *PD4030BG
MATRIX SW OUT
SUB
SENSOR
APFV(APAD)
CPU
SFTV(IFAD)
IC6 X24C01
DELV(DLAD)
AFAD
EEPROM AF-GAIN VR
SQAD
SQUELCH VR
IC1
HD6433833A74H
FRONT DISP UNIT
SHIFT V
UNIT
CTRL
IC3b *PD4030BG
Q2,Q4 DTA144EU
Q3,Q5 DTC144EU
REC
Q6 DTC114EU
D2 1SS355
REC
SW
J17
EXT
10.7MHz
J23
RIPPLE 13
Q5 2SC3650
FIL 25
D54 RD10MB2
12
EXT
24
AGC
J18 11
23
Q8
10
Q7
22
Q6
9 Mdat
Q5
Mck
21
L+5 Q4
OE
8
MST2
Q3
IC37 5-8054ALB
20
Q57 2SC4081 Q2
7
SP Q1
19
RESET
6
IC18 BU4094
18
5
IC34 17
EEPROM
HN58C256
4 COVER
16
DTX 3 J21
15
RS232
I/F DRX 2
14 EXT SP
IC28
1
DS14C232TM
RS-232C
J22
CI-V
CTRL
I/F
Q8
IC35 Q53 XP4501 Q7
CI-V
*PD4081 IC27 TC7W04F
Q6
Mdat
Q5
Mck
AF DA
SW OE Q4
Q73
MST3
Q3
2SK2036
Q2
IC20 M5282
ICI21
Q1
*PC1241
IC16 BU4094
RF RF
VR
AMP AMP
Q8
Q49
Q7
2SC4081
Q6
REC Mdat
AMP Q5
Mck
Q4
IC42 Q71 2SA1736 OE
MST1
S-8O54ALB Q72 2SK2036 Q3
13.8
Q2
13.8
RESET Q1
CTRL
IC15 BU4094
10 - 2
S1
SLEEP
SW-A BOARD
[MATRIX SW]
SW-B BOARD
[MATRIX SW]
VR-A BOARD
[APF VR]
[IF SHIFT VR]
VR-B BOARD
[DELAY VR]
[MEMO CH]
JACK BOARD
(FROM MAIN) J3
L+5
[PHONES]
J2
[REC]
J1
[REC REMOTE]
MAIN-A UNIT
FIL3
CTRL SW
FIL2
Q44 XP1213 Q45 XP1114
FIL1
CTRL SW
AM8
Q42 XP1213 Q43 XP1114
FM8
CTRL SW
WFM8
Q37 XP1213 Q41 XP1114
SSB8
CTRL SW
Q40 XP1213 Q56 DTA114EU
/WF8
SW
Q39 RN2427
FM5
SW
Q55 DTA114EU
MUTE
SW
MIXV
Q63 DTC144EU
Q36 DTC144EU Q35 RN2427
(TO RF-B,MIX)
MI5V
SW SW
FILS
SW
(TO MIX)
F4
F3
F2
(TO RF-B)
F1
IFBK
TSW2
TSW1
AGCF
NBS2
SW
NBS1
Q34 XP1213
FILC
SW SW
Q33 XP1213 Q32 DTA114EU