Sony SRF-M73 Service Manual ▷ View online
SRF-M73
– 7 –
– 8 –
– 9 –
– MAIN BOARD (Component Side) –
Adjustment Location:
– MAIN BOARD (Conductor Side) –
L4
AM VCO Voltage Adjustment
AM VCO Voltage Adjustment
RT1
FM Free-Run Adjustment
FM Free-Run Adjustment
CT1
AM Tracking Adjustment
AM Tracking Adjustment
L1
AM Tracking Adjustment
AM Tracking Adjustment
T1
AM IF Adjustment
AM IF Adjustment
FM Tracking Adjustment
CT2
L2
L2
TP
(MPX)
TP
(FM IN)
TP
(VT)
J1
SECTION 5
DIAGRAMS
5-1.
BLOCK DIAGRAM
18
20
16
13
19
24
22
FM
FRONT-END
FM IF AMP/
DISCRI
DECODER
AMP
SWITCH
BASS
BOOST
CONTROL
POWER
AMP
DET
REGULATOR
1/2
COUNTER
1/2
COUNTER
AM IF AMP/
DET
TUNING
INDICATOR
PD1
VCO
PD2
AM
FRONT-END
14
FM RF
IN
IN
FM/AM
MIX OUT
CF3: US
CF4, 5: PANAMA
10.7MHz
CF1
10.7MHz
BASS BOOST AMP
IC2
SYSTEM CONTROLLER,
LIQUID CRYSTAL DISPLAY DRIVER,
KEY CONTROL
IC101
EEPROM
IC105
CF2
450kHz
FM
RF
RF
26
FM DISCRI
FM
IF IN
IF IN
6
7
21
5
1
2
14
13
L-CH
OUT
R-CH
OUT
4
27
29
1
2
3
ST IND
AM
IF IN
IF IN
PILOT DET
LPF2
12
TUNE IND
9
AFC1/AGC
15
BAND
SELECT
PILOT DET
LPF1
PLL
LPF1
PLL
LPF2
VCO
AM OSC
FM OSC
AM RF
IN
IN
FM/AM FRONT-END,
FM/AM DET, MPX
IC1
RT1
FM FREE-RUN
L4
AM VCO VOLTAGE
CT2, L2
FM TRACKING
S1
FM SENS
T1
AM IF
CT1, L1
AM TRACKING
L.P.F.
B.P.F.
BPF1
FM VCO
BUFFER
BUFFER
Q1
FM/AM BAND
SELECT SWITCH
Q3
COMPARATOR
IC4 (1/2)
LIQUID CRYSTAL DISPLAY
LCD101
VOLTAGE
DETECT
IC102
B+ SWITCH
Q104
DC/DC
CONVERTER
Q103, T101
B+ SWITCH
Q6
AM IF
BUFFER
Q4, 5
LOW-PASS
FILTER
Q101
• SIGNAL PATH
: FM
: AM
05
POWER
AMP
MUTE
CONTROL
RIPPLE FILTER
Q2
KEY MATRIX
S101 – 111, 113 – 116
KS0 – KS3
KR0 – KR3
X101
75kHz
SYSTEM CONTROLLER (IC101),
EEPROM (IC105) B+
FM/AM TUNER (IC1),
HEADPHONE AMP (IC3) B+
BASS BOOST AMP (IC2) B+
PLL LOW-PASS FILTER CIRCUIT B+
AM IF AMP CIRCUIT B+
D105
–1
–2
IN1
IN2
HEADPHONE AMP
IC3
2
4
IN1
IN2
OUT1
OUT2
9
7
OUT1
OUT2
LP
GAIN
B+
VREF
5
6
7
COMPARATOR
IC4 (2/2)
3
2
1
B+
CT1
D1-1
L1
AM FERRITE-ROD
ANTENNA
L2
FM RF
(PANAMA)
POWER
XOUT
XIN
IF ON
CE
DET
IN
MT/SW
REG
VCC
AM IF IN
EO
VCOL
VCOH
BAND
CMP IN
24
D
ATA
15
CK
14
2
1
CS
SK
3
DI
4
DO
CS
16
25
2 1
50
6
12
10
53
MUTE
5
BEEP
52
3
17
21
20
19
DX
LOCAL
S2
MEGA
BASS
ON
OFF
D1-2
D3
CT2
D2
L4
AM OSC
L3
FM OSC
RV1
VOL
J1
(HEADPHONE)
2
+
DRY BATTERY
SIZE “AAA”
(IEC DESIGNATION R03)
2PCS. 3V
10 – 13
6 – 9
COM0 – COM3
31 – 34
SEG0 – SEG14
35 – 49
SRF-M73
– 13 –
– 14 –
– 15 –
– 16 –
• Waveforms
– KEY Board –
– KEY Board –
1
IC101
@¢
XOUT
200 mV/DIV, 10 µs/DIV
5-3.
SCHEMATIC DIAGRAM
•
See page 17 for IC Block Diagrams.
2
Q103 Base-1, Collector-2
(RADIO ON mode)
200 mV/DIV, 100 ns/DIV
(RADIO ON mode)
200 mV/DIV, 100 ns/DIV
3
Q103 Collector-1 (RADIO ON mode)
2 V/DIV, 100 ns/DIV
2 V/DIV, 100 ns/DIV
208 m Vp-p
13.3
µ
s
616 m Vp-p
243 ns
4.9 Vp-p
243 ns
Note on Schematic Diagram:
• All capacitors are in µF unless otherwise noted. pF: µµF
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
¢
: internal component.
•
C
: panel designation.
•
U
: B+ Line.
•
H
: adjustment for repair.
• Power voltage is dc 3 V and fed with regulated dc power
supply from battery terminal.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
(
no mark : FM
(
) : AM
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
• Signal path.
F
: FM
f
: AM
FM FREE-RUN
– 17 –
• IC Block Diagrams
– MAIN Board –
– MAIN Board –
IC1
CXA1238M-T6
IC2
LA3550MTP-1
IC3
LA4533M
VCO
REGULATOR
FM FRONT-END
AM FRONT-END
MPX
REGULATOR
MONO/STEREO
SELECT
DECORD
AMP
MUTING
AUTO
BLEND
TUNING
INDICATOR
AM IF/
DET
FM IF/
DISCRI
RIPPLE
FILTER
BAND-PASS
MUTE
1
27
28
29
30
24
25
26
21
22
23
18
19
20
16
17
2
3
4
5
6
7
8
9
PLL LPF1
PILOT DET LPF2
PILOT DET LPF2
ST IND/VCO CHECK
L-CH OUT
VCC
R-CH OUT
RIPPLE FILTER
AGC AFC1
10
AGC AFC2
13
FM IF IN
14
AM IF IN
15
BAND SELECT
11
GND
12
TUNE IND
1/2
COUNTER
1/2
COUNTER
PD1
PD2
FM/AM FE OUT
FM GND
FM RF IN
AM RF IN
FM RF
REG
FM OSC
AFC
AM OSC
MUTE
FM DISCRI
GND
PLL LPF2
MPX REG
VCO
ON/OFF
1
2
3
4
5
6
7
8
9
10
14
13
12
11
OUT-1
OUT-2
DET IN
DET OUT
REF
VCC
GND
LP-OUT
LP-GAIN
LP-IN
HP-2
HP-1
IN-2
IN-1
POWER
SWITCH
MUTE
BIAS
AMP
AMP
1
2
3
4
5
6
7
8
9
10 MUTE
R-OUT
GND
L-OUT
VCC
PWR
R-IN
GND
L-IN
REG
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