Panasonic AG-7350 Series Service Manual page 45

4-2-5. TILT & AZIMUTH ADJUSTMENT OF
THE A/C HEAD
<<NOTE>>
This procedure should be performed only when the A/C Head is
replaced or posts heights are readjusted.
<<TOOL>>
Alignment Tape ; VFM8180HADH
Check Light ; VFK0343
Screwdriver(+) ; Purchase locally
VHS Video Tape
1. Play back a VHS Video tape which the amount of tape
winding of a Supply Reel is more than the amount of
tape winding of a Take up Reel. Turn a screw (B) to
clockwise until Waving or Frilling appears in the lower
edge of P4 post as Figure M 11.
A/C Head Base Unit
Figure M14
<<NOTE>>
There is easy method to check Waving or Frilling.
If
there is
Waving or Frilling in the lower edge, White Black pattern which
is reflected on the tape will curve or not linear. (Figure M12)
2. Turn the screw (B) to counter-clockwise until waving or
frilling do not appear in the lower edge of P4 post.
3. Connect the scope CH1 to the Normal Audio Output
CH1 and the scope CH2 to the Normal Audio Output
CH2 on the rear panel.
4. Play back the 2-nd portion (Normal Audio 1OKHz) of the
alignment tape (VFM8080HQFP).
5. Adjust the screw (C) so that these phases of both chan-
nels match as shown in Figure M15.
CH1!\ANV
I
I
CH2!\NVV
Figure M15
4-7
6. Adjust the screw (C) and (B) so that CH1 and CH2
output levels become maximum, these phases of both
channels much at the same time (Figure M16). During
this adjustment the Lock screw (D) does not touch the
NC
Head Base as shown in Figure M17.
space
CH1
I
CH2 { \
A (\ (\
r
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I
V:V V
V_
t
Figure M16
Lock Screw (D)
----Screw
(C)
AIC Head Base
Figure M17
7. Turn the screw (C) to clockwise so that the difference of
phases of both channels become 180 degrees as
shown in Figure M 18.
CH1
CH2
Figure M18
9. Tighten the Lock screw (D) so that these phases of both
channels match as shown in Figure M 15.
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