1-
z
w
::E
l-
en
::;:)
..,
c
c(
..J
c(
0
z
c(
:r:::
0
w
::E
4-2-6. FINE ADJUSTMENT OF THE TAPE
GUIDE POST HEIGHT (P2
and
P3)
(LINEARITY)
<<TOOL>>
Alignment Tape ; VFM8180HADH
Post Adjustment Screwdriver ; VFK0329
<<NOTE>>
Before
playing
back
the alignment tape
playback
a normal
cassette tape
and
confirm correct transport.
1.
Connect the scope to TP3005
(AF)
on the video
(1)
board and
TP2201
on the servo
TP
board to Ext-trigger
the scope.
2.
Play
back the 2-nd portion (Monoscope
2)
of the align-
ment tape (VFM8180HADH)
3.
Turn the Tracking Control
VA
and adjust for maximum
VIDEO
FM
envelope.
4.
If
the
AF
envelope appears like example A or B
in
Figure
M20
then adjustment of the tape guide post
(P2
: Entrance)
is
necessary.
5.
Adjust the tape guide post
(P2)
with the post adjustment
screwdriver so that
the
AF
envelope waveform
at
the
en-
trance portion becomes flat
as
shown
in
Figure
M20-
C.
P1
Figure
M19
A
~~~~~~~~~~~~~~~~re
Portion
C
B.
Q
~~IIIIIIIIIIII"TTTT'r'T'M'TIIIIIIIIIIII~
I I
I
I
L-
__
.J
Figure
M20
6.
If
the
AF
envelope appears like example D or E
in
Figure
M21,
then adjustment of the tape guide post
(P3
:
Exit)
is
necessary.
7.
Adjust the tape guide post
(P3)
in
the same manner
as
the
P2
post so that the exit portion becomes flat
as
shown
in
Figure
M21-F.
4-8
r - - -
-,
Exit
Portion
DlliDrriiD
F
:.qffill
I I
I I
L--
__
j
Figure
M21
8.
Turn the Tracking
VA
fully clockwise and counterclock-
wise. The output envelope should vary nearly
parallel
with other condition as shown
in
Figure
M22.
Output
envelope Min.
11~1111111111111111111~1
~11111111111111111111111111111
Best
Output
envelope Max.
(Fix
position)
1)1
I
llli!llli[IIIIIIIIIIIbl
Good
nllilltl[[lllllllllllll!titrl
Good
Figure
M22
9.
Turn the Tracking
VA
into center fix position and adjust
for maximum
AF
envelope.
If
the
AF
envelope does not meet these specifications,
V1NO
>=
0.7
V2NO
>=
0.8
V3NO
>=
0.7
then repeat steps
4-9
again.
V1/V0~0.7
V2/V0~0.8
V3/V0~0.7
V1
Figure
M23
vo
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