Panasonic JU-475-4, Service Manual

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(7) Move th e stepper m o to r along th e base by hand u n til th e tw o w a v e fo rm s assume
approxim ately the same am plitude, and retighten the m ounting screws. (See Fig. 9-2.)
(8) Step the head outw ard (track 0) and inward (track 79), and confirm th a t the adjustm ent has
been completed.
(9) A fte r the radial adjustment, be sure to confirm track 0 sensor adjustm ent as described in
section 9-9.
Note: Alignm ents on sides 0 and 1 are adjusted a t the factory. If they are misaligned, adjust
them to meet the specifications o f Table 8-1.
w hen A > B
- - - x 100 (%)
w hen A < B
x 100 (%)
Fig. 9-2 Radial A lignm ent W aveforms (CATS EYE) Fig. 9-2-1 Stepper M o tor M ounting Screws
-
-
-
1
||1 -
- /
A
fit11 ifjijJ*,H,111t!
• fititl l itufi
-\
f
-
’
m
ll 1
-
-
-
9.7 Azimuth Verification
(1) Insert an alignm ent diskette. Seek to the track specified in the azim uth column o f Table 8-1.
(2) Set the oscilloscope in the same conditions as in section 9.3, and set horizontal deflection to
0.5 ms/division.
(3) Measure as shown below.
(4) Confirm th a t the measured value meets the specifications in the azim uth column o f Table 8-1.
m
P I
i
vij:*:*:-
Ä
s|§
W
I f
*
§
ill
H
m
When B = C When B>C When B <C
A zim uth = 0' Azim uth =
_ B -C
B - D
x (A) A zim uth = —— — x (A)
C - A
Fig. 9-4 A zim uth W aveforms
(A ): 12'