Read Sony SRF-H3 (serv.man2) Service Manual online
SRF-H3
Australian Model
SERVICE MANUAL
FM STEREO/AM HEADPHONE RADIO
SPECIFICATIONS
Frequency range:
FM: 87.6 – 108 MHz
AM: 530 – 1 710 kHz
AM: 530 – 1 710 kHz
Power output:
5.0 mW + 5.0 mW (at 10 % harmonic
distortion)
distortion)
Headphone type:
Dynamic
Power requirements:
1.5 V DC, one size AAA (R03) battery
Mass:
Approx. 132 g (4.7 oz) incl. a battery
Design and specifications are subject to change
without notice.
without notice.
Ver 1.0 2000. 07
— 2 —
SECTION 1
GENERAL
Getting Started
Installing the Battery
(See Fig.
B)
1
While pressing the battery
compartment lid, slide it to open.
compartment lid, slide it to open.
2
Insert one size AAA (R03) battery (not
supplied) with correct polarity.
supplied) with correct polarity.
3
To close the lid, press and slide the lid
down until it clicks.
down until it clicks.
When to replace the battery
Replace the battery when the sound becomes
weak or distorted. Remove the old battery and
insert a new one.
weak or distorted. Remove the old battery and
insert a new one.
Battery life (approximate hours)
Sony
Sony
alkaline
size AAA
size AAA
(R03)
(LR03)
FM reception
80
40
AM reception
100
50
Notes on the battery
• Align the battery correctly.
• The dry battery cannot be charged.
• To avoid damage from possible battery
• The dry battery cannot be charged.
• To avoid damage from possible battery
leakage, remove the battery when unit will
not be used for a long time.
not be used for a long time.
Wearing the Radio
1
1
Pull out the support band fully from
the headband.
the headband.
2
Adjust the headband and the support
band to fit your head.
band to fit your head.
Note on the support band
(See Fig. A)
When the radio not in use, put the support band
back by pushing down both ends as illustrated
and push it back underneath the headband.
back by pushing down both ends as illustrated
and push it back underneath the headband.
Note on the light reflector
(See Fig. A)
(See Fig. A)
This reflector reflects a car light at night for your
safety.
safety.
Playing the Radio
1
Set POWER to ON.
2
Set BAND to select FM or AM.
For FM, set SENS to LOCAL if interference is
prevalent and reception is too strong. Under
normal condition, set it to DX.
prevalent and reception is too strong. Under
normal condition, set it to DX.
3
Turn TUNE (tuning) to tune in a station.
4
Adjust the volume using VOL.
To turn off the radio
Set POWER to OFF.
AAA (R03) x 1
Head band
Light reflector
FM flexible
antenna
antenna
BAND
SENS
VOL
Driver
units
units
POWER
Support band
Insert the # side of the
battery first.
battery first.
Battery
compartment
compartment
Dial scale
A
TUNE
B
This section is extracted from
instruction manual.
instruction manual.
1.
Check the area of your repair for unsoldered or poorly-soldered
connections. Check the entire board surface for solder splashes
and bridges.
connections. Check the entire board surface for solder splashes
and bridges.
2.
Check the interboard wiring to ensure that no wires are
"pinched" or contact high-wattage resistors.
"pinched" or contact high-wattage resistors.
3.
Look for unauthorized replacement parts, particularly
transistors, that were installed during a previous repair. Point
them out to the customer and recommend their replacement.
transistors, that were installed during a previous repair. Point
them out to the customer and recommend their replacement.
4.
Look for parts which, through functioning, show obvious signs
of deterioration. Point them out to the customer and
recommend their replacement.
of deterioration. Point them out to the customer and
recommend their replacement.
5.
Check the B+ voltage to see it is at the values specified.
6.
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270˚C
during repairing.
• Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
• Be careful not to apply force on the conductor when soldering
or unsoldering.
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer.
— 3 —
SECTION 2
DISASSEMBLY
2
Cabinet front (R) assy
Cabinet rear (R) assy
Claws
Claws
1
Precision screwdriver
3
Holder
2
Push this
portion down.
Cabinet rear (R) assy
1
Unsolder two lead wires.
Model name (SRF-H3)
Gear (tuning)
1
Turn CV1 fully in the
direction of arrow.
Cabinet rear (R) assy
CV1
2
2-1. CABINET FRONT (R) ASSY
2-2. HOLDER (WITH DRIVER)
2-3. GEAR (TUNING) INSTALLATION
Note :
Follow the disassembly procedure in the numerical order given.
— 4 —
SECTION 3
ELECTRICAL ADJUSTMENTS
FM VCO Adjustment
Procedure:
1. Connect the frequency counter to 2 and 1 pins of IC2 as shown
the figure right.
2. Tune the set to 98 MHz.
3. Adjust RV1 for 76 kHz Hz reading on frequency counter.
3. Adjust RV1 for 76 kHz Hz reading on frequency counter.
Specification Value:
FM RF signal
generator
generator
Carrier frequency: 98 MHz
Modulation: no modulation
Output level: 0.1 V (100 dB)
Modulation: no modulation
Output level: 0.1 V (100 dB)
0.01
µ
F
FM lead wire antenna terminal
Connection:
Adjustment Location:
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
455 kHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter
L5
520 kHz
CT1-4
1,650 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L2
620 kHz
CT1-1
1,400 kHz
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
done by the trimmer capacitors.
FM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T2
10.7 MHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter
L4
87.35 MHz
CT1-3
108.05 MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3
87.35 MHz
CT1-2
108.05 MHz
[FM]
Setting:
BAND switch
BAND switch
: FM
[AM]
Setting:
BAND switch
BAND switch
: AM signal
AM RF signal
generator
generator
30% amplitude modulation by
400 Hz signal.
Output level: as low as possible
400 Hz signal.
Output level: as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
FM RF signal
generator
generator
75 kHz frequency deviation
by 1 kHz signal.
Output level: as low as possible
by 1 kHz signal.
Output level: as low as possible
0.01
µ
F
FM lead wire antenna terminal
level meter
set
SP1, SP2 (speakers)
32
Ω
+
–
–
Frequency counter
75,500 – 76,500 Hz
IC2 Pin
2
+
–
–
frequency counter
33 k
Ω
AUDIO Board
IC2 Pin
1
[AUDIO BOARD] (Component Side)
RV1: MPX VCO
IC2
L2: AM TRACKING
L3: FM TRACKING
T1: AM IF
CT1-4:
AM FREQUENCY
COVERAGE
CT1-1:
AM TRACKING
AM FREQUENCY
COVERAGE
CT1-1:
AM TRACKING
CT1-2:
FM TRACKING
FM TRACKING
CT1-3:
FM FREQUENCY
COVERAGE
FM FREQUENCY
COVERAGE
T2: FM IF
L5: AM FREQUENCY
COVERAGE
L4: FM FREQUENCY
COVERAGE
[TUNER BOARD] (Component Side)
