Sharp VT-3448X, Service Manual

Page: 38 / 144

Notes:
Place the tracking control in the center position, and adjust
the X-position so that the envelope becomes
maximum for easier rough adjustment of the tape drive
train.
In the rough adjustment, pay particular attention to the
outlet side.
Loosen the
setscrew
Figure
Figure
envelope
Head switching pulse
Figure
1
Adjustment
Adjustment of head height and azimuth
a) Connect an oscilloscope to the audio output terminal.
Using the alignment tape with linear audio
signal of 1 adjust the screws to maximize
the audio output, and adjust the screw to eliminate
wrinkles from the tape at the retain guide flange. (Refer
to
Repeatedly adjust the screws and in this
sequence until the audio output becomes the maximum.
to 3 times as ordinary)
Using the alignment tape which records a linear audio
signal of
6
finally adjust the screw until the audio
output becomes the maximum.
Note:
*
The screws and in the Figure
Adjustment of tape drive train and X-Position
a) Connect the oscilloscope to the test points for
envelope output.
The signal is to be triggered by the head
switching pulse
Play back the tape drive train alignment tape.
Push the or button to change the envelope
waveform from MAX to and to MAX.
Adjust the guide roller’s height on the supply and
up sides with an adjusting screw driver, to obtain an
envelope waveform that is as flat as possible.
If the tape is above or below the helical lead, the
waveform will take the shape shown in Figure
Adjust for maximum flatness of the envelope as the step
in page
When the tape is above the helical lead.
Supply side
,
\
Supply side guide roller
rotated in clockwise
direction (lowers guide
roller) to flatten
envelope.
Take-up side
Take-up side guide roller
rotated in clockwise
direction (lowers guide
roller) to flatten
envelope.
When the tape is below the helical lead.
1
Supply side
Supply side guide roller
rotated in counterclock-
wise direction (raises
guide roller)
to make the
tape float above the
helical lead. The
supply
side
guide roller is then
rotated in the clockwise
direction to flatten the
envelope.
Take-up side
Take-up side guide roller
rotated in counterclock-
wise direction (raises
guide roller) to make the
tape
float above the
helical lead. The take-up
side guide roller is then
rotated in the clockwise
direction to flatten the
envelope.
Figure