4-2-7. FINE ADJUSTMENT OF THE A/C
HEAD HEIGHT
<<NOTE>>
Before this adjustment 5-2-3. Coarse Adjustment
of
the A/C
Head Height should be performed.
<<TOOL>>
Alignment Tape ; VFM8180HADH
Nut Driver ; Purchase locally
1.
Connect a scope to the Normal Audio CH2 Output
on
the rear panel.
2.
Play back the 2-nd portion (Normal Audio 10kHz) of the
Alignment Tape
(VFM8180HADH)
3.
Adjust the Nut
(A)
(Figure
M24)
so that the CH2 output
level becomes maximum as shown
in
Figure
M25.
A/C
Head Base
Unit
Figure
M24
MMf_
Figure
M25
4-2-8. COARSE ADJUSTMENT OF THE
A/C HEAD HORIZONTAL POSITION
(X-VALUE)
<<NOTE>>
This procedure should be performed only when the A/C head is
replaced,
and
after performing the tape interchangeability
adjustment.
<<TOOL>>
H-Position Adjustment Screwdriver VFK0328
Alignment Tape ; VFM8180HADH
1
.
Set
the Tracking Control
VR
to the center detent(fixed)
position.
2.
Connect a scope
CH
1 to TP3005
(RF)
on the video
(1)
board, CH2 to the audio
CH1
output on the
rear
panel.
3.
Play
back the 4-th position (Monoscope 3 and Audio 1
Every 10-th field
is
skipped) of the Alignment tape
VFM8080HQFP.
4.
Adjust the
NC
head horizontal position screw so that
the phase of audio drop out and video
RF
envelope
drop-out becomes the same
as
shown
in
Figure
M26.
Horizontal
Position
Screw
Video RF
Audio
Drop
Out
Portions
Figure 3-26 Horizontal Position Adjustment of
NC
Head
<<NOTE>>
After completion the fine adjustment
of
the A/C head horizontal
position, the phase
of
Audio drop-out
and
Video RF envelope
drop-out
may
be changed slightly.
4-2-9. FINE ADJUSTMENT OF THE A/C
HEAD HORIZONTAL POSITION
(X-VALUE)
<<NOTE>>
This
procedure should be performed
only
when the A/C head is
replaced,
and
after performing the tape interchangeability
adjustment.
<<TOOL>>
H-Position Adjustment Screwdriver VFK0328
Alignment Tape ; VFM8180HADH
1
. Set the Tracking Control
VR
to the center fix position.
2.
Connect a oscilloscope to Video
RF
test Terminal on
the Front
Panel.
3.
Play back the 2-nd portion (Monoscope
2)
of the align-
ment tape (VFM8180HADti)
4.
Adjust the Horizontal Position Screw (Figure
M25)
of N
C head so that the
RF
signal becomes maximum level
as
shown
in
Figure
M27.
Head
Amp
Output
(RF Signal)
u.--------~
Jximum
----~,.~
__
L_I_~
4-9
Figure
M27
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