Onkyo DX-6930 - Page 13

eo ee
Dx.6920
ADJUSTMENT
PROCEDURES
Instruments required
Dual
trace
oscilloscope,
Frequency
counter,
AF
oscillator,
Test
disc
(SONY
YEDS-18),
AC
voltmeter,
Jitter
meter,
and
Socket
P4(Part
no.
25050138)
{
1. Focus offset adjustment
Load the test disc YEDS-18 on the tray and play the track 2.
Connect the oscilloscope or jitter meter to terminal P106.
(Oscilloscope)
Adjust R109 until a clear trace of waveform pattern as
shown photo 1 appear on the oscilloscope.
When the amount of jitter is broad, set R109 to mechanical
center.
(Jitter meter)
Adjust R109 until the jitter meter reading becomes
minimum.(Less than 10ns.)
After adjustment, disconnect the oscilloscope or jittter
meter.
Oscilloscope range (
Vertical : 0.SV/div.
Holizontal : 0.5 ps/div.
DC, Ground: Center
le af 00 eB
jarrnarr
N
-*.
Pn*.*.%.%.%,
Photo 1
2. Tracking offset adjustment
Load
the
test
disc
YEDS-18
on
the
tray
and
play
the
track
2.
Turn
R116
to
minimum
position.(Counter
clockwise)
Connect
the
oscilloscope
between
pin
3
(TR)
of
P107
and
pin
2
(GND)
of
P106.
Adjust
R106
until
the
center
of
tracking
error
signal
on
the
oscilloscope
becomes
GND
level.
Turn R116 to the mechanical center.
After adjustment, disconnect the oscilloscope.
ort hen.
P107
TR
Oscilloscope
P106
Vertical
:
500m
V/div.
Holizental : 1 ms/div.
Photo
2
GND
DC,
Ground:
Center
—-20-