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Servo Circuit Adjustments
6-3. Vertical jitter adjustment
Purpose:
To suppress vertical jitter during slow and still play.
Fault due to incomplete adjustment:
Vertical jitter appears in the picture during slow and
still play.
Test Equipment/Jigs and Connection Points
Monitor TV
Video output jack
Color bar generator: Video input jack
Blank tape
State of VCR
Record a color bar signal and play it using the same
VCR.
Adjustment Point
CH & (Remote control) _
CH ¥ (Remote control)
Adjustment Procedure
<LP vertical jitter correction>: Record in the LP mode
and play it back using the same VCR.
1) Press the "PAUSE" button to set the VCR to the still
Play mode.........
"2) Use the "CH &" or "CH aa buttons of ther remote
control to suppress vertical jitter of the picture.
<SP vertical jitter correction>: Record in the SP mode
and play it back using the same VCR.
1) Press the "PAUSE" button to set the VCR to the still
play mode,
2) Use the "CH &" or "CH ¥'"" buttons of the remote
contral to_suppress vertical jitter in the picture.
6-4, Forward slow tracking preset adjustment
Purpose:
To adjust the timing with which the brake pulse of the
capstan motor is generated during slow play so that
noise is minimum.
Fault due to incomplete adjustment:
Noise appears during slow play and the picture is not
clear,
Test EquipmentJigs and Connection Points
Monitor TV
: Video output jack
Color bar generator: Video input jack
Blank tape (E-180)
State of VCR
Slow tracking: Unplug the power cord to set the slow
tracking to the center.
Adjustment Point
CH & (Remote contro!)
CH _W (Remote control)
Adjustment Procedure
1) Record a signal on the middle of a E-180 blank tape
in the LP mode and play it back using the same
VCR.
;
2) Press the "CH &" and "CH W"
buttons of the remote
control (provided) simultaneously during playback
and hold them; then press the"PLAY" button
($2701) to set the VCR to the forward test slow mode.
3) Use the "CH &"
or "CH W " buttons so the slow feed
noise appears across the bottom of the monitor
screen and then it is driven out from the bottom of
the screen.
.
4) Check that no noise appears on the monitor screen.
5) Press the "PLAY" button to return the VCR to the
playback mode (the preset data is written to the
EEPROM).
6) Perform the same procedure to perform slow tracking
preset adjustment in the SP mode.
Do not press the reset switch after adjustment 'ties
the power is not turned on as the preset value could
drift. If the preset value drifts, turn the power on.
and press the reset switch again for recovery.
~
6-5. Reverse slow tracking preset adjustment
Purpose:
To adjust the timing with which the brake pulse of the
. . capstan motor is.generated during reverse slow play so
that noise is minimum.
:
ag
Fault due to incomplete adjustment:
Noise appears during reverse slow play and the picture
is not clear.
Test Equipment/Jigs and Connection Points.
pe!
Monitor TV
: Video output jack
i
Color bar generator: Video input jack
w t
t e
Blank tape (E-180)
=
State of VCR
Slow tracking: Unplug the power ey to set the slow
tracking to the center.
Adjustment Point
eas
ate
p o
ones
pererns
CH & (Remote control)
CH ¥-(Remote control)
Adjustment Procedure
1) Record a signal on the middle of a E- 180 blank tape
in the LP mode and play it back using the same,
VCR.
2)Press the "CH &" and "CH ¥ " buttons of the remote
control (provided) simultaneously during still play
and hold them, then press the "PLAY" button.
;
($2701) to set the VCR 'to the reverse test: slow mode.
3) Use the "CH A"
or "CH '¥." buttons so the slow feed
noise appears across the bottom of the monitor
'screen and then it is driven.out fromthe bottom.of
the screen.
4) Check that no noise appears on the monitor screen.
5) Press the "PLAY" button to return the VCR to the
playback mode (the preset data is written to the
EEPROM).
6) Perform the same procedure to perform reverse slow
tracking preset adjustment in the SP 'mode.
Do not press the reset switch after adjustment when
the power is not turned on as the preset value could
drift. If the preset value drifts, turn the power on
and press the reset switch again for recovery.
3-5
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