Mechanical Adjustment; Electrical Adjustment; Deck Section - Sony SA-VA100 Service Manual

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SECTION 4
MECHANICAL ADJUSTMENTS
Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback heads
erase head
capstan
2. Demagnetize the record/playback head with a head demagnetizer.
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 sup-
ply voltage unless otherwise noted.
Torque Measurement
Torque meter
Torque
FWD
CQ-102C
FWD
CQ-102C
back tension
REV
CQ-102RC
REV
CQ-102RC
back tension
FF/REW CQ-201B
FWD tension CQ-403A
TE
L 13942296513
REV tension
CQ-403R
SECTION 5
ELECTRICAL ADJUSTMENTS

DECK SECTION

0 dB=0.775V
1. Demagnetize the record/playback head with a head damagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjusted.
4. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in this
service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit adjust-
ment.)
6. The adjustments should be performed for both L-CH and R-CH.
7. Switches and controls should be set as follows unless otherwise
specified.
DOLBY NR switch: OFF
DIRECTION switch: D
FUNCTION switch: TAPE
Tape Signal
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10 kHz, –10 dB
P-4-A100
3 kHz, 0 dB
WS-48B
315 Hz, 0 dB
P-4-L300
.
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pinch rollers
rubber belts
idlers
Meter reading
30 to 60 g • cm
(0.42 - 0.83 oz • inch)
1 to 5 g • cm
(0.014 - 0.069 oz • inch)
30 to 60 g • cm
(0.42 - 0.83 oz • inch)
1 to 5 g • cm
(0.014 - 0.069 oz • inch)
65 to 90 g • cm
(0.91 - 1.25 oz • inch)
110 g or more
(3.88 oz or more)
110 g or more
(3.88 oz or more)
Used for
Azimuth Adjustment
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Tape Speed Adjustment
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Level Adjustment
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8
Test Mode
Perform the tape deck adjustment after setting the test mode.
0 The sections where recording is started are memorized. When
the 0 button is pressed after recording, the tape is rewound to the
section where recording was started, and stops.
In this mode, the input source can be selected using the FUNCTION
button. To playback the recorded tape, select the TAPE using the
FUNCTION button.
To play back the tape, select TAPE using the FUNCTION button.
To exit the mode disconnect the AC plug from the outlet.
Method:
In the STANDBY state, press the DOLBY NR button,
p button, and DISC 4 button together.
Record/Playback Head Azimuth Adjustment
Note: Perform this adjustments for both decks.
Procedure:
1. Mode : Playback
test tape
P-4-A100
(10kHz, –10dB)
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3 6 7 1 3 1 5
set
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw so
that outputs match within 1 dB of peak.
L-CH
output
peak
within
level
1dB
R-CH
peak
screw
position
co
.
9 4 2 8
level meter
0 5 8 2 9 9 4 2 8
+
–
VIDEO 1 OUT
within 1dB
screw
L-CH R-CH
position
m
peak peak
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