SRF-18
SRF-18
10
10
3-2. SCHEMATIC DIAGRAM
• See page 8 for IC Block Diagrams.
IC B/D
IC B/D
TOTAL CURRENT
FM VOLUME MIN: 24mA
AM VOLUME MAX: 22mA
FM VOLUME MIN: 18mA
AUDIO IN: 6mA
FM VOLUME MAX: 38mA
VOLUME MIN: 1.1
1.5
2.9
1.5
1.2
0
VOLUME MAX: 0
0
1.5
1.5
2.6
2.7
1.9
2.5
2.7
1.9
2.5
0.9
0
0.6
0.9
0
0.6
0.3
0
0.3
0.3
0
0.3
FM TRACKING
CT101-2, L101
CT101-4, L103
AM FREQUENCY
COVERAGE
FM 2ND
OSC
FM
VCO
CT101-1, L106
FM FREQUENCY
COVERAGE
AM TRACKING
CT101-3, L105
2.9
2.9
2.9
0
2.9
0 (2.9)
2.7
2.7
2.9
0.5 (0)
0.9
0.9
0
0
2.9
0 (2.9)
2.9
2.9
0 (1.4)
0
0.5
0.4
0.6
2.7
2.7 (2.9)
10p
C103
10p
CV101-2
CT101-2
CV101-4
CT101-4
VCC
VCC
C102
2p
C106
1500p
C108
JW106
W101
JW107
JW301
JW304
JW108
100p
C105
4700p
C112
0.01
C136
2.2k
R102
1.5k
R103
1
C109
0.22
C113
3.3k
R104
1
C111
0.22
C110
L-1154HD
D102
1000p
C135
0
JC102
SL001
GND
JW109
BPF101
BPF I
G
O
MC2837
D101
220p
C134
0
JC101
220p
C123
47p
C124
1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
FE GND
AM RF IN
ACC AFC
FM 1ST
OSC
TV 1ST
OSC
+VCC
FM IF
GND
AGC
MUTE
DET
OUT
MPX IN
PD1
PD2
ST
IND
FM RF IN
TV RF IN
+VDD FE
FM RF
IMAGE ADJ
OL
AGC
FM 2ND LOCAL
AM OSC
TUN IND
PLL
1
PLL
2
PLL
VCO
VCO CTRL
R CH
L C
H
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
C120
220p
C142
0
R109
330
R108
22p
C139
CT101-1
CV101-1
REG
CEN
HOT
1
MPX
(VCO)
TP
JW105
JW110
C129
1
C133
1
-1
-2
-2
-1
-4
-3
C132
10k
JW104
JW102
JW101
JW202
JW502
JW503
JW103
R106
10
R105
1
C127
6.8
C128
10V
100
C125
1
C126
6.3V
IC101
FM/AM RF AMP,
MIX, VCO, MPX
CXA1129N
IC101
4.7
C104
220
R101
25V
2.2
R107
100
R401
0.015
C114
33k
R131
JW111
JW112
33k
R151
1000p
C115
0.015
C116
1000p
C117
RCH
RCH
GND
GND
GND
GND
HPL
SPL
HPR
SPR
GND
LOUT
ROUT
LCH
RCH
LCH
GND
LCH
220k
R451
220k
R452
220k
R431
220k
R432
100k
R435
DSC500100L
Q431
L_IN
GND
R_IN
AUDIO IN
J401
4700p
C431
4700p
C451
0.01
C402
10
R436
10
R456
2.2k
R434
2.2k
R454
1
C453
1
C433
100k
R455
DSC500100L
Q451
1
C455
1
C435
22
C401
10V
OFF
AUDIO IN
RADIO
1
C251
1
C231
100
R301
JW303
15k
R351
68k
R333
DSC500100L
Q331
LINE AMP
Q331, 351
1
C331
JW302
15k
R331
22
C301
0.01
C302
10V
22
C201
1
C202
47
R231
47k
R252
2.2k
R253
1
C252
1
C255
DSC500100L
Q251
LINE AMP
Q231, 251
47
R251
10V
IC201
POWER AMP
CXA1522N
IC201
1
2
3
4
5
6
7
8
IN 2 L
NC
NC
NF 2
GND
PGND 2
OUT2
RIPPLE
IN 1 R
REG
VOL
NF 1
GND
PGND 1
OUT1
VCC
16
15
14
13
12
11
10
9
22
C203
10V
C204
1
C257
1
TP (BATT–)
GND
TP (BATT+)
0
JC501
TH501
JW501
1N4002-B5
D501
2.2k
R233
1
C232
DSC500100L
Q231
1
C235
1
C258
1
C238
1
C205
2.2k
R204
2.2k
R202
0
R302
0
R335
0
R355
1
C333
1
C353
0
R203
22
C209
1
C237
10V
470
C206
38uH
L201
JW201
4V
220
C259
4V
220
C239
4V
1
AMP VCC
C207
150
R254
0
R255
150
R234
0
R235
(L-ch)
(R-ch)
0
R205
47k
R232
J201
AUDIO OUT
J301
2.2k
R332
2.2k
R352
22
R334
22
R354
68k
R353
DSC500100L
Q351
1
C351
MAIN BOARD
VOL
50k
1
3
2
RV201
W203
SPR
W204
SPRG
W201
SPL
W202
SPLG
SIZE “AA”
DRY BATTERY
(IEC DESIGNATION LR6)
2PCS. 3V
LINE AMP
Q431, 451
FM TELESCOPIC
ANTENNA
ANT1
FERRITE-ROD
ANTENNA
AM
L105
FM
S101
AM
FM
TP
OSC
2ND
TUNE
TUNING
CV101
POWER
S501
13
11
16
A
3
17
10
8
6
I
E
2
9
G
D
5
J
B
C
7
F
1
4
15
14
12
H
CV101-3
CT101-3
100
R201
(FRONT)
CABINET
SP1
SUB ASSY
(GND)
TP
FM 1st OSC
L106
(DET)
TP
(FM_IN)
TP
VCO
L104
FM
L102
OSC
2nd
AM OSC
L103
FM RF
L101
