Harman Kardon FL8550 Service Manual page 24

(D) Tracking Servo Loop Gain Adjustment
Connections point
U1 (KA9220C)
Pin 53 (R13)
Pin 52 (R14)
See fig.4
i. Set the frequency generator output to 1KHz and 100mV.
ii. Press the play key and press skip key to move the pickup to halfway across the disk
(R=35mm).
iii. Adjustment VR4(track gain) so that the Lissajous waveform is symmetrical above
the X axis Y axis.
Tracking Gain Adjustment
Higher gain
Settings
1. Oscilloscope probe: X10
3. Oscilloscope setting
CH1: 50mV/division
CH2: 20mV/division
Remark: X-Y mode
Vref
Fig 4
Optimum gain
24
State Adjustment location
Play State Adjustment VR4
Lower gain
FL8550