Advertisement
LD-V4300D
10. RF GAIN ADJUSTMENT
•
Purpose: To
set the amplitude
of
the RF
signal to
the
optimum value.
• Symptoms when incorrectly adjusted:
Dropout occurs
frequently.
Measurement
equipment
Measurement equipment
Player condition
&
jigs
connecting
points
•
Oscilloscope
•
Oscilloscope:
In
the
•
Normal
mode:
•
Test disc:
GGV1003
FTSB
assembly
• Still
mode
CH
I:
Between
TPl-1
• TILT
servo
OFF
(RF)
and GND
Adjusting procedure
I.
Play the
test disc and search
for frame
#
15,000.
2. Connect
the oscilloscope to TPl-1 in the
FTSBassem-
bly
to
observe
the RF signal.
3. Adjust VRI
in the
PREB
assembly
so
that
the
amplitude of
the RF
signal becomes
300mV
±20mV.
(Photo
11)
Adjustment diagram
Waveforms
Adjusting points
•
VR
I
in
the
FTSB assembly
•
OsciKoscope
renge:
AC
t
OOmV,div.,
2mS/div.
FTSB n
Hmbly
D..,
0
D
I
CN4
~ - - - - ,
@
0
0
0
0
0
0
§ : a
1§1§
Fig. 10-1
I
OOmV
±
20mV
Photo
11
RF
signal
Advertisement
