Mechanical Adjustments; Electrical Adjustments; Test Mode; Tape Deck Section - Sony XR-4880 Service Manual

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3 7 63 1515 0

MECHANICAL ADJUSTMENTS

1. Clean the following parts with a denatured-alcohol-moistened
swab:
playback head
rubber belt
idlers
2. Demagnetize the 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 power supply
voltage unless otherwise noted.
• Torque Measurement
Mode
Forward
Forward
Back Tension
Reverse
Reverse
Back Tension
FF, REW
• Tape Tension Measurement
Mode
Forward
TE
L 13942296513
Reverse
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SECTION 4
pinch roller
capstan
Torque Meter Meter Reading
30 - 65 g•cm
CQ-102C
(0.42 - 0.90 oz•inch)
0.5 - 4.5g•cm
CQ-102C
(0.01 - 0.06 oz•inch)
30 - 65 g•cm
CQ-102RC
(0.42 - 0.90 oz•inch)
0.5 - 4.5g•cm
CA-102RC
(0.01 - 0.06 oz•inch)
60 - 200 g•cm
CQ-201B
(0.83 - 2.78 oz•inch)
Tension Meter Meter Reading
more than 90 g
CQ-403A
(more than 3.18 oz)
more than 90 g
CQ-403R
(more than 3.18 oz)
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ELECTRICAL ADJUSTMENTS

2 9
8

TEST MODE

This set have the test mode function. In the test mode, FM Auto
Scan/Stop Level and MW Auto Scan/Stop Level adjustments can
be performed easier than it in ordinary procedure.
<Set the Test Mode>
1. Set the "OFF" mode.
2. Push the preset
3. Push the preset
4. Press the preset
5. Then the display indicates all lights, the test mode is set.
<Release the Test mode>
[OFF]
1. Push the
See the adjustment location from on page 16 for the
adjustment.

TAPE DECK SECTION

Tape Speed Adjustment
Setting:
test tape
WS-48A
(3 kHz, 0 dB)
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3 6 7 1 3 1 5
Procedure:
1. Put the set into the FWD PB mode.
2. Adjust adjustment resistor for inside capastan motor so that
the reading on the speed checker or frequency counter becomes
in specification.
Specification: Constant speed
Speed checker
–1.5 to +2.5%
Adjustment Location: See page 16.
co
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– 13 –
SECTION 5
9 4 2 8
[4]
button.
[5]
button.
[1]
button for more than two seconds.
button.
0 dB= 0.775 V
speed checker
or
frequency counter
4 Ω
set
– +
0 5 8 2 9 9 4 2 8
speaker out terminal
Frequency counter
2,955 to 3,075Hz
m
9 9
9 9