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PD-6010
Oscilloscope
Check items/
Vv
H
specifications
6
TANGENTIAL ADJUSTMENT
Load the test disc.
Set the player to test mode (see page 53)
Using the MANUAL
SEARCH
FWD key ( —& ), move the
pick-up to the disc edge to enable the tangential adjust-
ment screw to be seen from the left hand side (see Figure
11-5).
Tangential
adjustment
screw
Press the TRACK
FWD
(D>), PLAY
( (> ), and PAUSE
( 00
) keys in that order to close all servos, (The PAUSE
indicator will light up.)
Photograph 11-9
TP2
Tangential
Best eye pattern
Observe the TP2 pin 4 RF (RF output) in the oscilloscope
pin 4
adjustment
and adjust the tangential adjustment screw to obtain the
Fig. 11-5
Tangential Adjustment
(RF
screw
clearest eye pattern. (Figure 11-5).
output)
The optimum
position
is the midpoint between the two
positions where the eye pattern starts to deteriorate when
the tangential
adjustment
screw
is turned clockwise and
counter clockwise.
Guidelines
for
this adjustment:
in addition
to a clear
overall waveform,
adjust to obtain relatively slender lines
(see photograph 11-8) Where single '"'diamond"' shapes are
formed in the eye pattern.
To
make
the waveform
easier
to observe,
insert a 10
kohm
resistance
(or 5 kohm
if the waveform
is hard to
see) in the tip of the probe as shown in Figure 11-4.
Photograph 11-10
Observation point
———————————SSSSSSSSSS
Unaligned
Optimum adjustment
Unaligned
Photograph 11-8
Photograph 11-11
59
60
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