Sharp DV-NC70U Service Manual page 31

Adjustment
4. A/C head X value adjustment
1 Fix A/C head arm screws 1 by the method described
in "8-17 Replacement 3".
2 Playback the alignment tape (VROATSV), and
shortcircuit between TP801 and TP802. As a result
the auto-tracking is automatically cancelled, so that
the X value adjustment mode is set.
3 Move the A/C head with the X value adjustment gear
driver by the method shown in Figure 8-34, and
adjust the A/C head so as to get the maximum ATR
signal waveform. (Note: At this time adjust so as to
get the maximum ATR signal waveform nearest the
A/C head position which has been set in case of X
value rough adjustment as stated in 8-19, 3-2.)
4 Adjust the playback switching point (Refer to the
electric adjustment method.)
5 Playback the self-picture-recorded tape, and check
the flatness of ATR signal waveform and sound.
When the tape is above the helical lead.
Supply side
Supply side guide roller Take-up side guide roller
rotated in clockwise rotated in clockwise
direction (lowers guide direction (lowers guide
roller) to flatten roller) to flatten
ATR signal. ATR signal.
When the tape is below the helical lead.
Take-up side 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
ATR signal.
Figure 8-31.
Notes:
When the A/C head X value adjustment is performed, be
sure to perform at first X value rough adjustment (refer to 8-
19, 3-2).
31
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
ATR signal.
1
Figure 8-32.
DV-NC70U/C
DV-NC72U