AMSTRAD CTM644 - Disc Drive Alignment Checks (Continued)

ALIGNMENT CHECKS
.....-
,.....
-
500fJsec
Fig. 5-1 Index burst waveform
Amplitude
ratio
(%)
100
80
60
40
20
~
~
~-
~
--
~
~~
~
JI __ Ibl
lajI-IE}
Inner: bla x 100%
Outer: alb x 100%
10 20 30 40 50
Amount of Off - center (I-' )
Fig. 5-2 Off-centre calibration curve
(Effective width of read head is 180u)
Fig. 5-3 Azimuth burst
-48'
-72< +48' n+72'
-
12HH
O
B
-
0-8·&88-
+
12
-BG-HB-
Fig, 5-4 shows azimuth burst in the cases of azimuth -12',0' and +12.
13