Teac FD-55 Series, Maintenance Manual

Page: 134 / 216

(j ) Confirm that both of the calculated values in items (g) and (i) are
within the following range.
True value of misalignment: 30%, Max.
(k) For a double sided FDD, execute items (d) through (j) for side 0
and side 1 heads respectively.
(L) If the value in item (j) or (k) is out of the specified range, adjust
the track alignment according to the following procedure:
i) Loosen two fixing screws of the stepping motor a little,
ii) Insert the alignment adjustment jig or M3 screw from the back
side of the FDD as shown in Fig. 431.
iii) Repeat step-in and step-out operations and adjust the misalignment
to be the smallest on the alignment check track during both
step-in and step-out operations by turning the jig or the screw
(stepping motor moves little by little).
Note: When you adjust the alignment by observing the lobe pattern
using the oscilloscope, pay attention to the calibration value
on the alignment disk label and the ambient relative humidity.
0 Calibration value + (Relative humidity - 50) x K ^ 0:
When the left side lobe pattern level, VA is assumed as "l”,
lobe pattern ratio should be so adjusted that*the right side
lobe pattern level VB takes the following value:
Calibration value + (Relative humidity - 50) x K
L ~ 100
0 Calibration value + (Relative humidity- 50) x K < 0:
* *
When the right side lobe pattern level, VB is assumed as "1",
lobe pattern ratio should be so adjusted that the left side
lobe pattern level VA takes the following value.
4096