Pioneer PDR-04 - Manual (Page 71)

PDR-04
6.3.21 Tracking Servo Loop Gain Adjustment Adjustment 2
• Objective
• Symptom when out
of adjustment
To optimize the tracking sen/o loop gain.
Playback does not start, during searches the acutuator is noisy, or tracks are skipped.
• Measurement instru­
ment connections
See Fig.7.
(SERVO UCOM BOARD assy)
[ Settings ]
CHI : 0.1 V/div. X-Y mode
CH2:10 mV/div.
• Player state
• Adjustment
location
• Disc
Test mode, play
VR202 (TE. GAIN)
(SERVO UCOM BOARD assy)
STD-903
[ Procedure ]
(1) Set the AF generator output to 1.2kHz and 2Vp-p.
(2) Move the pickup to midway across the disc (R = 35mm) with the MANUAL / TRACK SEARCH FWD ►► or REV
◄◄ keys.
(3) Press the FINALIZE key, the PLAY ► key, then the PAUSE
II
key In that order to close the respective servos and put
the player Into play mode.
(4) Adjust VR202 (TE. GAIN) so that the lissajous waveform is symmetrical about X axis and the Y axis.
CN204
.... t"i.............i"i............. i
Fig. 7
M 1 : i
\ f -1
li........ I... ...........................
... .............................^....
.... i
Higher gain Optimum gain Lower gain