Azimuth Verification - Panasonic JU-475-4 Service Manual

(7) Move th e stepper m o to r along th e base by hand u n til th e tw o w a ve fo rm s assume
approxim ately the same am plitude, and retighten the m ounting screws. (See Fig. 9-2.)
(8) Step the head outward (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.
-
-
1
- /
A
fit 11 ifjij J * , H ,1 1 1
-\
'
-
m
-
Fig. 9-2 Radial A lignm ent W aveforms (CATS EYE)
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
v i j : * :* :-
Ä
s|§
W
*
§
ill
H
I f
m
When B = C
A zim uth = 0'
-
-
|| 1
when A > B
t! • f i t
- - - x 100 (%)
it l l itufi
when A < B
f
ll 1
- x 100 (%)
-
When B>C
Azim uth = _ B -C
B -D
Fig. 9-4 Azim uth Waveforms
Fig. 9-2-1 Stepper M otor M ounting Screws
When B <C
x (A) A zim uth = — —— x (A)
C - A
(A ): 12'