Service manual

24
VC-A410U(B)/H810U(B)
VC-A411U/H811U
VC-A420U/H820U
3 Next, press the tracking button (+), (–) and change
the ATR signal waveform from max to min and from
min to max. At this time adjust the height of supply
and take-up side guide roller with the adjustment
driver (JiGDRiVERH-4) so that the ATR signal wave-
form changes nearly parallel.
4 If the tape is lifted or sunk from the helical lead
surface, the PB ATR signal waveform appears as
shown in Figure 4-35.
5 Press the tracking button (+), (–) and make sure that
the ATR signal waveform changes nearly parallel.
6 Finally check tape crease near the reverse guide. If
tape crease is found, remove it as stated in 4-17
"HEIGHT ADJUSTMENT OF REVERSE GUIDE"
item 3.
3 Move the A/C head with the X value adjustment gear
driver by the method shown in Figure 4-33, 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 4-18, 3- 2.)
4 Tighten finally the screws 1 and 2. Be sure to tighten
at first the screw 1 and then the screw 2. Final
tightening torque is 0.6N·m (If the screw 2 is tightened
first, the X value may deviate.)
5 Adjust the playback switching point (Refer to the
electric adjustment method.)
6 Playback the self-picture-recorded tape, and check
the flatness of ATR signal waveform and sound.
Notes:
When the A/C head X value adjustment is performed, be
sure to perform at first X value rough adjustment (refer to 4-
18, 3-2).
PB ATR
Signal
Head switching pulse
Figure 4-34.
4. A/C head X value adjustment
1 Tentatively fix A/C head arm screws 1 and 2 by the
method described in 4-15 "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.
Take-up side Supply side Take-up side
Adjustment
Supply side
Supply side guide roller
rotated in clockwise
direction (lowers guide
roller) to flatten
ATR signal.
Take-up side guide roller
rotated in clockwise
direction (lowers guide
roller) to flatten
ATR signal.
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.
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.
Figure 4-35.
When the tape is below the helical lead.When the tape is above the helical lead.
Figure 4-36.
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