Mechanical Adjustments; 4, Electrical Adjustments - Sony MEGA BASS CFS-W310L Service Manual

CFS-W310L |
SECTION 3
MECHANICAL ADJUSTMENTS
PRECAUTION
1. Clean the following parts with a denatured-alcohol-
moistened swab :
record/playback head
erase head rubber belts
capstan idlers
2. Demagnetize the record/playback head with a head
demagnetizer. (Do not bring the head demagnetizer
close to the erase head.)
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound
to the parts adjusted.
5. The adjustments should be performed with the rated
power supply voltage unless otherwise noted.
6. Power supply voltage : 9Vdc
pinch roller
Torque Measurement
Meter Reading
20 — 60g*cm
(0.28 — 0.83 ozeinch)
Forward
CQ-102C
2 — 6g¢cm Forward
ea (0.028 — 0.083 ozsinch)
more than 45gecm
aa (more than 0.62 ozeinch)
Tape Tension Measurement
Meter Reading
more than 70g
cle (more than 2.47 02)
more than 45g*cm
(more than 0.62 ozeinch)
SECTION 4
ELECTRICAL ADJUSTMENTS
4-1. TAPE RECORDER SECTION
Standard Output Level
025¥(— 1068)
Test Tape
[| Type | Signal | Usedtfor
3kHz, 0dB Tape Speed Adjustment
Tape Speed Adjustment
Procedure :
Mode : playback
test tape
WS-48A
PHONES jack
| Speed | Deck | Adjustment Point | frequency counter
8 | enfin
Normal 2,970 — 3,000Hz
8 [enfin
5,500 — 5,900Hz
Frequency difference between the beginning and the end of the
tape should be within + 1.5%.
Adjustment Location :
—bottom view—
fmt |
RV303
TAPE SPEED
4-2. RADIO SECTION
Setting :
BAND switch : FM
FM rf signal
generator
telescopic antenna input
22.5kHz frequency deviation by
400Hz signal.
Output level : as low as possible
MW/LW Section
Setting :
BAND switch : MW or LW
AM ff signal
30% amplitude modulation by 400Hz
signal.
Output level : as low as possible
VTVM
(range : 0.5 — 5V AC)
PHONES jack
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on VT VM.
Ly,12 ¢ check
98MHz 108MHz
MW TRACKING ADJUSTMENT
Adjust for a maximum reading on VT VM.
621kHz
LW TRACKING ADJUSTMENT
Adjust for a maximum reading on VTVM.
162kHz 261kHz
Adjustment Location : TUNER board (See page 10.)
@ Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
VCO Adjustment
procedure :
FM ff signal
generator
telescopic antenna input
Carrier frequency: 98MHz
Modulation:
Output level:
no modulation
0.1V (100dB)
1. Connect frequency counter to the positions shown below.
2. Tune the set to 93MHz.
3. Adjust RV1 for 76kHz + 50Hz reading on the frequency
counter.
Adjustment Location : TUNER board (See page 10.)
FM TUNING VOLTAGE Adjustment
Procedure :
1. Connect the digital voltmeter to the TUNER board.
2. Tune the set to 108MHz.
3. Adjust L3 for 8V + 0.1V reading on the digital voltmeter.
Adjustment Location : TUNER board (See page 10.)
MW TUNING VOLTAGE Adjustment
Procedure :
1. Connect the digital voltmeter to the TUNER board.
2. Tune the set to 531kHz.
3. Adjust T2 for 1.5V + 0.1V reading on the digital voltmeter.
4. Tune the set to 1,61 1kHz.
5. Adjust CT7 for 8V + 0.1V reading on the digital voltmeter.
Adjustment Location : TUNER board (See page 10.)
LW TUNING VOLTAGE Adjustment
Procedure :
1. Connect the digital voltmeter to the TUNER board.
2. Tune the set to 153kHz.
3. Adjust CT8 for 0.9V + 0.1V reading on the digital voltmeter.
Adjustment Location : TUNER board (See page 10.)