Fisher AD-530 - Adjustment Procedures (Continued); Advanced Gain Alignment and Operation Check

ADJUSTMENT PROCEDURES (continued)
FOCUS GAIN ADJUSTMENT
1. Apply P202 to the center position, and place the test disc 1.
KICK GAIN ADJUSTMENT
Place the test disc (Modern Wave I) on the table load.
(Modern Wave II) on the table load. 2. Set the oscilloscope to NORMAL TRIG., set the EXT.
2. Connect the measurement tool described in the last sec- TRIG. pin to external trigger, and input the trigger from
tion to focus coil pin (CN2). test terminal (CN11-2) TRH pin to the oscilloscope.
3. Apply Power Switch to the set and PLAY the first item on 3. Next connect test terminal (CN10-3) HF pin to Channel 1
the test disc. Now apply a signal of 900Hz and 0.3Vp-p of the oscilloscope, and connect test terminal (CN12-3)
from the signal generator to the measurement circuit. TE pin to Channel 2.
4. Set the oscilloscope to X-Y operation, and while observ- 4. Apply Power Switch to the set and PLAY the first item on
ing the lissajous waveform adjust P202 to the point where
the phase difference is 90° as shown in Fig. 5 below.
the test disc, and the press the PAUSE button. Now ob-
serve the waveforms for HF and TE with triggers applied
from test terminal (CN11) TRH pin. At this point, adjust
P206 so that a kick pulse waveform of about 1.5 tracks as
shown in Fig. 6 below is obtained.
wm -<— Tracking Error Out
Pe d40a hod40 ms
Fig. 5 — HF waveform
TRACKING GAIN ADJUSTMENT
1. Apply P204 to the center position, and place the test disc
(Modern Wave IL) on the table load.
2. Connect the measurement too! described in the last sec-
tion to the tracking coil pin CN2.
3. Apply Power Switch to the set and PLAY the first item on ‘le
the test disc. Now apply a signal of 1350Hz and 0.3Vp-p
from the signal generator to the measurement circuit.
4. Set the oscilloscope to X-Y operation, and while observ-
ing the lissajous waveform adjust P204 to the point where
the phase difference is 90° as shown in Fig. 5 above.
NOTE:
Adjustment must be performed
so curve section in Fig. 6 appears.
Fig. 6
ACCESS OPERATION CHECK
Vary the FREE RUN FREQUENCY from a center value of
4.3218MHz to +50kHz (4.2700MHz ~ 4.3700MHz), and
have the pick-up search from the track closest to the
center to the outermost track and then back into the track
nearest the center, to check that operation is stable.
NOTE:
After this adjustment is completed, be sure to adjust back
If these two adjustments are performed, the TRACKING to 4.3218MHz.
OFFSET must also be adjusted.