Read Sony ICF-903L Service Manual online
ICF-903L
– 9 –
– 10 –
4-1. BLOCK DIAGRAM
SECTION 4
DIAGRAMS
MW
ANT
ANT
LW
ANT
SW
ANT
FM
MW
LW
SW
SW
LW
MW
FM
FM
MW
LW
SW
SW
LW
MW
FM
L2-1, CT1
L2-2, CT2
L3, CT3
SW
OSC
AM
FE
FM
SW
DET
FM
BPF
FM FE
FM
OSC
L6, CT5
MW/LW
OSC
CT4, L5
B+
CT6
S1-3
TUNING
CV1-1
TUNING
CV1-2
S1-5
S1-7
S1-4
S1-6
(LW)
AM
ANT
FM
ANT
FM IF
TUNING
METER
LPF
CONT
AF
POWER
AMP
AM IF
DET/AGC
FM
RF
FM
OSC
D2, 3
L8,L9, L10,
CT7, CT8
BPF1
Q1
ANT1
FM/SW
TELESCOPIC
ANTENNA
6
11
13
15
24
25
28
10
8
CF2
10.7MHz
CF3
10.7MHz
CF1
455kHz
18
20
5
17
3
CF4
10.7MHz
Q6-8
TONE
VOL
RV2
PON 3V
ATT
S1-1
(LW/SW)
RV1
CN401
(1/2)
Q2
IC2
FM/AM CIRCUIT
AF POWER AMP
AF POWER AMP
PON 3V
S1-1
(FM)
(FM)
Q9
Q202
D201
D5
KI/02
KI/06
KI/04
KI3
17
1
14
19
KI/03 20
KI/07 2
KI/01 16
IC201
KEY IN CONTROL
IC205
IC205
IC205
IC205
13
1
2
IC202
SWITCH
RV205
FM1
12
11
10
RV206
FM2
6
9
8
RV208
FM3
RV201
FM VT
VOLTAGE
5
3
4
RV202
(FM TUNING)
FM3
FM2
FM1
KI0
11
KI1
12
KI2
13
XIN
7
XOUT
8
CN201
POWER
CONT
POWER
CONT
ON/OFF
DRIVE
Q101, 102
PON 6V
6V
3V
Q103
3
5
2
DC/DC
CONV
CONT
CONT
IC101
2
1
3V
REG
IC204
PON 8V
D301
TUNE
FM3
SW303
FM2
SW302
FM1
SW301
FM3
D303
FM2
D304
FM1
D302
MANUAL
SW304
FM1
FM2
FM3
KEY BOARD
MAIN BOARD
X201
3.68MHz
PON 6V
Q201
3V
Q203
PON 3V
EPJ1
v
SP1
SPEAKER
S401
D402
D401
OPERATION
STANDBY
ON
PON 6V
6V
D101
1.5V x 4
ACJ1
AC IN
CN401
(2/2)
T401
POWER
TRANSFORMER
POWER BOARD
04
AM
OSC
T1
455kHz
5
7
9
11
2
1
14
13
CT4, L5
MW FREQUENCY
COVERAGE
CT1, L2-1
MW
TRACKING
T1
MW
IF
CT6
LW FREQUENCY
COVERAGE
CT2, L2-2
LW
TRACKING
CT5, L6
SW FREQUENCY
COVERAGE
CT3, L3
SW
TRACKING
CT8, L8
FM FREQUENCY
COVERAGE
CT7, L9, L10
FM
TRACKING
• Signal path
: MW
: FM
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