Azimuth Verification - Panasonic JU-475-4 Service Manual

(7) Move the stepper motor along the base by hand until the two waveforms assume
approximately the same amplitude, and retighten the mounting screws. (See Fig. 9-2.)
(8) Step the head outward (track 0) and inward (track 79), and confirm that the adjustment has
been completed.
(9) After the radial adjustment, be sure to confirm track 0 sensor adjustment as described in
section 9-9.
Note: Alignments on sides
0
and
1
are adjusted at the factory. If they are misaligned, adjust
them to meet the specifications of Table 8-1.
-
==
==
-
when A > B
B
A
x
100(%)
when A < B
A
-B-
x
100(%)
Fig.9-2 Radial Alignment Waveforms (CATS EYE) Fig.9-2-1 Stepper Motor Mounting Screws
9.7 Azimuth Verification
(1) Insert an alignment diskette. Seek to the track specified in the azimuth column of 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 that the measured value meets the specifications in the azimuth column of Table 8-1.
c
c
D
D
When B=C
Azimuth = 0'
When B>C
Azimuth = B - C
x
(A)
B-D
Fig.9-4 Azimuth Waveforms
-9-
When B<C
Azimuth = C- B
x
(A)
C-A
(A): 12'