5-28
2. VCO Adjustment (PD-137 Board)
Set the VCO free-run frequency. If deviated, the LCD screen will
be blurred.
Mode
PLAY
Signal
Arbitrary
Measurement Point
CH1: Pin
7
of CN881
(HSY)
CH2: Video terminal of A/V
OUTjack
(75
Ω
terminated)
Measuring Instrument
Oscilloscope
Adjustment Page
D
Adjustment Address
D7 (NTSC)
DD (PAL)
Specified Value
T = 2.04 ± 0.1 µs (TYPE ST)
T = 1.92 ± 0.1 µs (TYPE SA)
Menu setting:
1) VIDEO OUT of SET UP menu
.................................. NTSC (NTSC mode)
(This adjustment must be performed in NTSC mode, so don’t
set the menu setting to “PAL” )
Adjusting method:
Order Page Address Data
Procedure
1
0
01
01
Change the data and set the
2
D
D7
phase difference (T) to the
specified value.
3
D
D7
Press PAUSE button.
4
D
D7
Read the data and this data is
named D
D7
Conver D
D7
to decimal
5
notation, and obtain D
D7
’
(Note)
Calculate D
DD
’ using
following equations (decimal
6
calculation)
D
DD
’ = D
D7
’ + 26 (TYPE ST)
D
DD
’ = D
D7
’ + 40 (TYPE SA)
Conver D
DD
’ to a hexadecimal
7
number, and obtain D
DD
(Note)
8
D
DD
D
DD
Press PAUSE button.
Note:
Refer to table 5-2-2. “Hexadecimal-decimal conversion
table”
Processing after Completing Adjustments:
Order Page Address Data
Procedure
1
0
01
00
H
T
CH2
magnified
CH1
CH2
CH1
T: Between the center of HSY signal rising and
VIDEO SYNC signal rising
Fig. 5-1-21