Panasonic JB-3300 Technical Manual page 366

9.4 Output Modulation Verification
Vmax —- Vmin
M (%) = x100 using the value obtained in 9.3, and check that the
Vmax +Vmin
calculated value is 20% or less.
Maximum Voltage Valve : Vmax
eG
vera Voltage
Minimum Voltage Valve : Vmax
eee
Fig. 9.1 Modulation
9.5 Radial Alignment Adjustment
introduction
This adjustment is normally not necessary.
lf the mounting screwsfor the stepper motor loosen, or if parts become defective, or if a compatibility error occurs, check and readjust
according to the following procedure.
Steps (4) to (9) should be performed regardless of the type, CE or DAD alignment diskette used. Use an alignment diskette suitable to
the type of FDD to be adjusted according to table 3.1.
(1) Insert an alignment diskette.
CAUTION:
Be sure to leave the alignment diskette under room conditions for 20 minutes before adjustment.
(2) Step to the track specified in the Radial alignment column of Table8.1.
(3) Leave the oscilloscope in the same condition as mentioned in section 9.3.
(4) Check the output waveforms for sides 0 and 1. They should appear as in Fig. 9.2.
(5) The two waveforms should appear in the amplitude ratio in the R/A column of Table 8.1 or better.
(6) Ifthe specified ratio is not satisfied, loosen the two mounting screwsfor the stepper motor.
(7) Move the stepper motor along the base by hand until the two waveforms assume approximately the same ampli-
tude, and retighten the mounting screws. (See Fig. 9.2.)
(8) Step the head outward (track 0) and inward (track 40 or 79), and confirm that the adjustment has been completed.
(9) After the radial adjustment, be sure to confirm track 00 sensor adjustment 9.8 and carriage limiter 9.9.