C.E.C. 530CD - Page 14

ADJUSTMENT PROCEDURES ccontinuea)
$6 Signal
Generator
6
Main P.C.B. :
CN2 “3 10K 0.047
5 x
1
Tracking Gain — ii =
Duaitrace
Oscilloscope
Focus Gain 1k Oat ‘
6
Pick-up
:
10K
0.047
CN2 3 |
2
1
@ Remove connector CN2 from the pick-up and connect the
measurement circuit between the PCB and pick-up.
e@ The IC used is TA7256P
@ VR control 2kQ-B shorts IN and SG. 1kHz 1Vp-p is supplied
from the signal generator, and adjustment is made for
minimum output from OUT.
Simplified adjustment procedure Precise adjustment procedure
@ Focus gain adjustment @ Focus gain adjustment
P105 is set to a position 15° from its mechanical center as = 1. Connect the measurement circuit shown above, turn on the
shown in the diagram below. power, and mount the test disk YEDS4.
2. Playback the first selection on the test disk, and apply a
1,100Hz 0.5Vp-p signal from the signal generator.
3. Observe the resurge waveforms on the oscilloscope, and
adjust P105 so that the phase difference of outputs X and Y
from the measurement circuit is 90°.
@ Tracking gain adjustment
P104 is set to a position 15° from its mechanical center as
shown in the diagram below.
15°
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