830D
6.14.7.3 Adjustment Procedure
(200
tpi only)
CAUTION
THE POLARITY
OF
THE COMPENSA TION VALUE FOR
EACH CE
CARTRIDGE IS CRITICAL. IF CARTRIDGE
INTERCHANGE
IS
NOT
A PRE-REQUISITE, PERFORM
THE
ADJUSTMENT
PROCEDURE FOR TOP LOAD 100 TPI
MODELS DESCRIBED
IN
PARAGRAPH 6.14.7.2.
(1)
Allow the disk drive to stabilize
in
the
Ready
mode for
30
minutes (minimum).
(2)
Maintain oscilloscope setting established in Paragraph 6.14.7.1 except change
Channel 1 sensitivity to
50-100
mv per division.
(3)
Observe the waveforms shown in Figure
6-31
and
determine which direction the
heads must
be
moved.
(4)
Locate the two radial positioning screws
on
the selected head.
(5)
By
loosening one screw
and
tightening the other, position the selected
head
until
the waveform of Figure
6-31C
is obtained.
Then
tighten both screws without
disturbing the adjustment.
(6)
Align both heads
In
the
same
manner.
(7)
Note the sign value
of
the compensation factor which is printed
on
the
CE
cartridge.
• If the compensation factor is
zero
(0), the magnitude
of
the offset Is
-*..50
!-linch.
Perform the radial
head
alignment described in Steps
(1)-(6)
and
Step (8) •
• A positive
(+)
compensation factor indicates that the
CE
track was written'
offset
away
from the spindle;
in
this case, the magnitude of the offset is
+50
to +
150
!-linch.
• A negative
(-)
compensation factor indicates that the
CE
track
was
written
offset toward the spindle;
in
this case, the magnitude of the offset is
-50
to
-150
!-linch.
NOTE
If
a head cannot
be
adjusted
to
obtain
the
minimal lobe
pattern, the head may not be flying correctly. This
condition
can
be caused
by
either a dirty disk
or
head,
incorrect head load force,
or
damaged head[s].
6-66
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