Sony SRF-M80 Service Manual ▷ View online
SRF-M80
5
2-3.
MAIN BOARD
Note: When installing the main board, adjust S1 and the adaptor (sens).
5
claw
adaptor (sens)
5
claw
6
main board
S1
3
holder (H/P)
key board
4
Remove two solders.
2
screw
(B1.7
(B1.7
×
6)
1
knob (vol)
6
SRF-M80
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
RV1
999 kHz
AM VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L2
531 kHz
2.5
± 0.1 V
Confirmation
1602 kHz
8.6
± 0.3 V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
621 kHz
CT1
1,404 kHz
FM VCO VOLTAGE CONFIRMATION
Frequency Display
Reading on Digital Voltmeter
87.5 MHz
8.3
± 0.3 V
108 MHz
13.6
± 0.3 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3
98.0 MHz
Adjustment Location: MAIN board (See page 7)
FM STEREO ADJUSTMENT
Setting:
BAND button: FM
BAND button: FM
1. Connect the frequency counter to TP (FM ST) and TP (+B) as
shown the figure below.
2. Tune the set to 87.5 MHz.
3. Adjust RV2 for 75.9 to 76.1 kHz reading on the frequency
3. Adjust RV2 for 75.9 to 76.1 kHz reading on the frequency
counter.
Adjustment Location: MAIN board (See page 7)
0 dB=1
µ
V
[AM]
Setting:
BAND button : AM
BAND button : AM
[FM/TV]
Setting:
BAND button: FM
BAND button: FM
• Repeat the procedures in each adjustment several times, and the
tracking adjustments should be finally done by the trimmer ca-
pacitors.
pacitors.
• Remove FM antenna in FM adjustment.
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level:
as low as possible
modulation by
400 Hz signal
Output level:
as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
+
–
–
level meter
set
16
Ω
i
jack (J1)
digital voltmeter
TP (VT)
TP (FM GND)
100 k
Ω
MAIN board
SECTION 3
ELECTRICAL ADJUSTMENTS
set
MAIN board
TP (FM IN)
TP (FM IN)
MAIN board
TP (FM GND)
TP (FM GND)
0.01
µ
F
Carrier frequency : 87.5 MHz
Modulation
Modulation
: no modulation
Output level
: 0.1 V (100 dB)
FM RF SSG
33 k
Ω
+
+
–
–
MAIN board
TP (FM ST)
TP (+B)
TP (FM GND)
frequency counter
1
µ
F/50 V
digital voltmeter
TP (VT)
TP (AM GND)
100 k
Ω
MAIN board
FM RF signal
generator
22.5 kHz frequency
deviation by 400 Hz
signal
Output level:
as low as possible
deviation by 400 Hz
signal
Output level:
as low as possible
+
–
–
level meter
i
jack (J1)
set
MAIN board
TP (FM IN)
TP (FM IN)
MAIN board
TP (FM GND)
TP (FM GND)
16
Ω
0.01
µ
F
SRF-M80
7
7
Adjustment Location:
– MAIN BOARD (Component Side) –
AM Tracking Adjustment
RV1
AM IF Adjustment
RV2
FM Stereo Adjustment
L3
FM Tracking Adjustment
L2
AM VCO Voltage Adjustment
CT1
L1
L1
TP
(AM GND)
TP
(FM GND)
TP
(FM ST)
TP
(FM IN)
TP
(+B)
TP
(VT)
– MAIN BOARD (Conductor Side) –
SRF-M80
8
8
BASS
BOOST
CONTROL
POWER
AMP
DET
BASS BOOST AMP
IC2
SYSTEM CONTROLLER
IC101
2
1
13
14
S1
FM SENS
B.P.F.
BPF1
LIQUID CRYSTAL DISPLAY
LCD101
VOLTAGE
DETECT
IC102
B+ SWITCH
Q6
DC/DC
CONVERTER
Q104, T101
POWER
AMP
MUTE
CONTROL
RIPPLE FILTER
Q5
KEY MATRIX
S101 – 115
KS0 – KS3
KR0 – KR3
X101
75kHz
SYSTEM CONTROLLER (IC101) B+
FM/AM RF AMP (IC1),
HEADPHONE AMP (IC3) B+
BASS BOOST AMP (IC2) B+
PLL LOW-PASS FILTER CIRCUIT B+
D102
–1
–2
IN2
IN1
HEADPHONE AMP
IC3
2
4
IN1
IN2
OUT2
OUT1
9
7
OUT1
OUT2
LP
GAIN
POWER
XOUT
XIN
CE
BA
TT LOW
DET
IN
MUTE SW
VCOL
VCOH
BAND1
24
HOLD
51
25
1
50
VOLTAGE
DETECT
IC103
53
6
12
10
MUTE
5
M/BASS
4
BEEP
52
16
21
AMP
15
20
EO
19
DX
LOCAL
RV3
VOL
J1
(HEADPHONE)
i
+
DRY BATTERY
SIZE “AAA”
(IEC DESIGNATION R03)
2PCS. 3V
10 – 13
6 – 9
COM0 – COM3
31 – 34
SEG0 – SEG14
35 – 49
25
22
16
18
17
FM
RF AMP
FM
LPF
MPX
DECODER
FM
OSC
AM/FM: 1/2
FMIN
MPXI
ARFI
150kHz
DETO
45kHz
FMRO
AMLO
FTLO
29
IFCT
12
BAND
1
VCO
FM/AM RF AMP,
MIX, OSC, DET, MPX
IC1
AM
OSC
FM
LMT
FM
DET
AGC
AMP
AM
BPF
19
REGV
FMBF
AM
RF AMP
26
+
+
35
LOUT
3
ROUT
4
36
PSN
REGULATOR
VCO
RV2
FM STEREO
RV1
AM IF
L3
CT1, L1
L3
FM RF
AM TRACKING
L1
AM
FERRITE-ROD
ANTENNA
L2
AM OSC
L5
FM OSC
CT1
D3
D2
(1/2)
D2 (2/2)
D5
AM VCO
VOLTAGE
FM TRACKING
BASS BOOST
SWITCH
Q4
LOW-PASS
FILTER
Q101
FM VCO
AMP
Q103
B+
FM VCO
BUFFER
BUFFER
Q1, 102
S117
HOLD
ON
OFF
: FM
: AM
• SIGNAL PATH
SECTION 4
DIAGRAMS
4-1.
BLOCK DIAGRAM
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