Downconv Board - Icom IC-R20 Service Manual

11-8 DOWNCONV BOARD

RF _ IN
GND
2.2V
C49
R30
0.01
180k
C47
R29
0.7V
1k 0.01
R20
10
R19
820
R18
330
C22 C21
0.33 470p
C37
470p
D8
1SV308
D7
1SV308
C39
1p
R23
4.7k
C43
470p
R5
4.7k
C4
8p
D1
1SV308
R4
4.7k L2
8.2nH
C41
15p
DOWNCONV BOARD
2.8V
RF _ IN
GND
C53
R32
1k 0.01
R31
C48
1k
0.01
Q6
IC4
2SC5277
MB15E03SL
1
OSCI
2
OSCO
3
VP
4
VCC
5
DO
6
GND
7
XFIN
8
FIN
C50
C52
470p
470p
C26
0.1
+3V
2.6V
C23
4.7
C12
10
L3
0.82µH
L6 D3 C13 L4
0.22µH 1SV245 22p 12nH
C40 R33
4p 1k
R25
R22 R27 C38
1k
4.7k 4.7k 470p
C34
470p
L7
1.5nH
R28 C36
10 2p
C30 C29 C28
2p 1p 1p
C32 C31
22p 12p
L10 L9
2.2nH 3.9nH
1001 MHz or 2002 MHz LO
IC2
µPC2749TB
3 GND 4
C3 C2
OUT 5
2 GND
6p 8p
GND 6
1 IN
VCC
L1
8.2nH
2.4V
C42
12p
C51
470p
PLLCK
PLLDATA
PLLESTB
16
R
15
P
2.8V
14
L/F
13
ZC
12
PS
R16
11
LE
2.3V
10 150
DAT
9
CLK
R15
R14
C18 C17
220 56k
470p 470p
R17
1k
Q2
2SC5006
2.8V
C14
R10 C19
0.1
470p
47
C8
C10
2p
1p
Q1
C9 R7
2p 330
2SC5006
R9
C11 C58 R8
4.7k
0.001 0.1 10k
Q5
XP1113
4
C54 C55
R26
47p 47p
1k
5
C35
L8
470p
6.8nH
R21
D6
27k
1SV308
D5 C27
10p
1SV308
Q4
2SC5624
DOWN _ CONV 3V
C56 R2
47p 470
3 4
LO PS 5
2
GND VCC 6
1
RFI IFO
C1
IC3
10p
µPC2757TB
C6
R1 180
470p
[USA], [EUR]
C5
470p
11 - 7
RF _ IN
GND
C16
470p
C15
470p
+3V
+3S
Q3
UNR911J
R13
15
R12
10
R11
15
3
DOWN _ CONV
2
1
2.8V
1.7V
C44 R6
470p 4.7k
C7 L11 D2
1p 6.8nH 1SV308
C45 C46 R3
3p 3p 4.7k
Explanatory notes
VOLTAGE LINE
RF _ IN
8
GND
7
OSC
6
PLLCK
to
5
PLLDATA
RF unit
4
PLLESTB
HJ10
3
GND
2
IF _ OUT
1
J1
+3S
6
+3V
5
to
4
RF unit
2GLO
3
HJ11
1GLO
2
GND
1
J2