Sony SRF-18 Service Manual ▷ View online
SRF-18
5
1-4. MAIN BOARD
2
knob (band)
qa
MAIN board
9
holder (DC)
0
battery terminal (-)
3
pointer
convex part
convex part
chassis block
chassis block
Knob (tune) is turned until it stops
in the direction of an arrow.
in the direction of an arrow.
ditch
ditch
6 chassis block
8
screw (1.7)
5
screw (1.7)
1
two claws
4 screw (B)
(1.4
u 6)
7
Remove the solder.
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guide line
guide line
pointer
pointer
SRF-18
6
1-5. KNOB
(TUNE)
chassis block
cutting
lack
lack
boss
washer
chassis block
tweezers
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3
knob (tune)
1
washer
1
Cutting lack of a washer is united with boss and
it inserts in the direction of an arrow.
2
Washer is moved in the direction of an arrow
with
tweezers.
2
gear (midway)
chassis block
1-6. GEAR
(VC)
3
MAIN board
2
gear (VC)
boss
gear (VC)
CV101
axis
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1
Boss of a gear (VC) checks that it is in a position
as shown in a figure, and attaches to the axis
of
CV101.
2
Gear (VC) is turned until it stops in the direction
of an arrow.
1 screw (M1.7)
Note: Tightening torque (0.07
± 0.005 N·m)
SRF-18
SRF-18
7
7
SECTION 2
ELECTRICAL ADJUSTMENTS
0 dB = 1
V
FM 2ND OSC ADJUSTMENT
Refer to the connecting location and adjustment location.
Refer to the connecting location and adjustment location.
Setting:
Band: FM
Band: FM
unit
MAIN board
TP (GND)
MAIN board
TP (DET)
MAIN board
TP (FM IN)
MAIN board
TP
(FM 2ND OSC)
FM RF signal
generator
generator
Carrier frequency:
98 MHz
Modulation:
no modulation
Output level:
100 dB
98 MHz
Modulation:
no modulation
Output level:
100 dB
PV (100 mV)
0.01
PF
1
PF
10
PF
Frequency
conunter
conunter
+
+
Procedure:
1. Connect the frequency counter to TP (FM 2ND OSC) as shown
1. Connect the frequency counter to TP (FM 2ND OSC) as shown
the fi gure.
2. Tune the unit to 98 MHz.
3. Adjust L102 so that the reading is set to standard value on
3. Adjust L102 so that the reading is set to standard value on
frequency counter.
Standard value : 56.5 to 57.0 MHz
[AM]
Setting:
Band: AM
Volume: max
Setting:
Band: AM
Volume: max
AM RF signal
generator
generator
30% amplitude modulation by 400Hz
signal.
Output level : as low as possible
signal.
Output level : as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
[FM]
Setting:
Band: FM
Volume: max
Setting:
Band: FM
Volume: max
unit
MAIN board
TP (GND)
MAIN board
TP (FM IN)
FM RF signal
generator
generator
22.5 kHz frequency
deviation by
400Hz signal
Output level : as
low as possible
deviation by
400Hz signal
Output level : as
low as possible
0.06
PF
16
:
+
–
–
i jack (J201)
level meter
• Repeat the procedures in each adjustment several times, and
the tracking adjustments should be fi nally done by the trimmer
capacitors.
capacitors.
• Remove FM antenna in FM adjustment.
Refer to the connecting location and adjustment location.
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L103
520 kHz
CT101-4
1750 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L105
620 kHz
CT101-3
1400 kHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L106
86.5 MHz
CT101-1
109.5 MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L101
86.5 MHz
CT101-2
109.5 MHz
FM VCO ADJUSTMENT
Refer to the connecting location and adjustment location.
Refer to the connecting location and adjustment location.
Setting:
Band: FM
Band: FM
unit
MAIN board
TP (GND)
MAIN board
TP (DET)
MAIN board
TP (FM IN)
MAIN board
TP (VCO)
FM RF signal
generator
generator
Carrier frequency:
98 MHz
Modulation:
no modulation
Output level:
100 dB
98 MHz
Modulation:
no modulation
Output level:
100 dB
PV (100 mV)
0.01
PF
1
PF
10
PF
Frequency
conunter
conunter
+
+
Procedure:
1. Connect the frequency counter to TP (VCO) as shown the fi g-
1. Connect the frequency counter to TP (VCO) as shown the fi g-
ure.
2. Tune the unit to 98 MHz.
3. Adjust L104 so that the reading is set to standard value on
3. Adjust L104 so that the reading is set to standard value on
frequency counter.
Standard value : 37.95 to 38.05 kHz
Connectiong and adjustment location:
– MAIN Board (Component Side) –
– MAIN Board (Conductor Side) –
L104
FM VCO adjustment
L102
FM 2ND OSC
adjustment
L106
FM frequency
coverage
adjustment
L103
AM frequency
coverage
adjustment
CT101-4
(AM OSC)
AM frequency
coverage
adjustment
CT101-1
(FM OSC)
FM frequency
coverage
adjustment
L101
FM tracking
adjustment
L105
AM tracking
adjustment
CT101-3
(AM ANT)
AM tracking
adjustment
CT101-2
(FM ANT)
FM tracking
adjustment
TP
(DET)
TP
(GND)
TP
(VCO)
TP
(FM 2ND OSC)
TP
(FM IN)
SRF-18
SRF-18
8
8
SECTION 3
DIAGRAMS
For Schematic Diagrams.
Note:
• All capacitors are in μF unless otherwise noted. (p: pF) 50
• All capacitors are in μF unless otherwise noted. (p: pF) 50
WV or less are not indicated except for electrolytics and
tantalums.
tantalums.
• All resistors are in Ω and 1/4 W or less unless otherwise
specifi ed.
• C : Panel designation.
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
(In addition to this, the necessary note is printed in each block.)
• A : B+ Line.
• H : Adjustment for repair.
• Power voltage is dc 3 V and fed with regurated dc power
• H : Adjustment for repair.
• Power voltage is dc 3 V and fed with regurated dc power
supply from TP (BATT+) and TP (BATT–) on the MAIN
board.
board.
• Voltages are dc with respect to ground under no-signal
(detuned) conditions.
no mark : FM
( ) : AM
( ) : AM
*
: Impossible to measure
• Voltages are taken with VOM (Input impedance 10 M
).
Voltage variations may be noted due to normal production
tolerances.
• Signal path.
F :
F :
FM
f :
AM
E :
AUDIO
IN
For Printed Wiring Boards.
Note:
• X : Parts extracted from the component side.
• Y : Parts extracted from the conductor side.
• W : Indicates side identifi ed with part number.
•
• X : Parts extracted from the component side.
• Y : Parts extracted from the conductor side.
• W : Indicates side identifi ed with part number.
•
: Pattern from the side which enables seeing.
(The other layers’ patterns are not indicated.)
• IC Block Diagrams
– MAIN Board –
IC101 CXA1129N-T4
1
2
6
8
FM/TV
RF AMP
FM/TV
MIX
FM/TV
1ST LOCAL
OSC
AFC
AM
RF AMP
OVER LOAD
AGC
MIX
1
MIX
2
PSN
1
PSN
2
AGC
AF AMP
LPF
DETUNE
DET
FM
LPF
AM
BPF
LOCAL
OSC
1/2
COUNTER
FM/TV
SELECT
FM
DISCRI
FM
LIMITTER
AMP
AM IF AMP
(FM TUN IND)
AM
DET
AGC
TUNING
IND
VCO
MUTE
SEP
CONTROL
ST.
DECORDER
INPUT
BUFF
VCO
LEVEL
CONTROL
BUFF
AMP
DC
AMP
PD
SYNC
DET
R CH
AMP
L CH
AMP
AMP
LOAD
SELECT
1/2
COUNTER
FM/AM
SELECT
M/ST.SW
ST.IND
FM/TV
30 29
25
24 23
26
28
27
22
20
3 4 5
7
9
10
11
12
13 14
15
16
17
18
19
21
FM/AM
FM/TV
38KHz
0
/2
FM/TV
FM/AM
19KHz
/2
19KHz
0
38KHz
FM IN
TV IN
NC
FM RF
GAIN ADJ
OL
AGC
2ND OSC
AM OSC
TUN IND
PLL1
PLL2
VCO OSC
VCO CONT
R OUT
L O
U
T
ST
IND
PD2
PD1
MPX IN
DET
OUT
MUTE
AGC2
NC
FM IF
NC
TV OSC
FM OSC
AGC1
AM IN
NC
IC201 CXA1522N
PRE/POWER 2
PRE/POWER 1
VOLUME
REGULATOR
IN1
REG
VOL
NF1
GND1
P-GND1
OUT1
VCC
IN2
NC
NC
NF2
GND2
P-GND2
OUT2
RIPPLE
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
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