xR-P7 4o￿M, XR-P64{)M, XR-P34()M xR-P7 4{), XR-P64{), XR-P340

I TrackingServo Loop Gain Adjustment

o Objective

To optimize the tracking servo loop gain.

OSymptom when out of adjustment

oMeasurement Instrument Connections

lProcedurel

Playback does not start, during searchesthe actuator is noisy, or tracks are skipped.

SeeFig. 5.

o

Player State

Test mode,play

ISettings]

o

Adjustment Location

vR8151(TRK GAN)

CH1

 

 

 

50mVzldivision

o

Disc

YEDS_7

X-Y mode

 

 

 

CHz

 

 

 

20mVzldivision

 

 

 

1. Set the AF generatoroutput to l.2kHz and 2Vp-p.

2 . PresstheMANUAL/TRACKSEARcHFwD>> . >>!keyorREV!<< . << ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

halfway acrossthe di5g(ft:35mm), then pressthe DOLBY NR key, thePLAY /PAUSE >/llkey twice in that order to close the corresponding servos and put the player into play mode.

3. Adjust VR8151 (TRK GAN) so that the Lissajous waveform is symmetrical about the X axis and the Y axis.

( 1 0 :1 )

Pin3 (TRIN)

 

Pin4 (GND)

1.2kHz

( 1 0 :t 1 2 V P - P

 

Pin2 (TRER)

 

0.001uF

Low pass filter

Fis.

Tracking Gain Adjustment

ffi

HighergainOptimumgainLower gain

1 - 3 7

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Image 37
Pioneer XR-P640M XR-P7 4oM, XR-P64M, XR-P34M xR-P7 4, XR-P64, XR-P340, TrackingServo Loop Gain Adjustment, CH1, YEDS7