Va Gain Adjustment - Sony Digital Betacam DVW-707 Maintenance Manual

7-9. VA Gain Adjustment

7-9. VA Gain Adjustment
Note
. Use an 89.9%-reflective chart in this adjustment as
possible. (Refer to Section 7-1-4.)
. If a "16:9" chart is not keep on hand, shoot a''4:3" chart
so that the chart width is aligned with the underscanned
monitor frame.
Preparation
. OUTPUT/DCC switch (inside panel)
. Shoot a grayscale chart (16:9) in the full underscanned
monitor frame.
. WHITE BAL switch (inside panel)
. AUTO W/B BAL switch (front panel)
(Perform the automatic black balance adjustment.)
. On the setup menu, set as follows.
PAGE : S35*PRESET WHT
ITEM : COLOR TEMP <P> : 3200
ITEM : R GAIN <P>
ITEM : B GAIN <P>
Adjustment Procedure
1. Select the 16:9 mode.
PAGE : S14*WIDE SCREEN
ITEM : 16:9/4:3 MODE
2. Equipment : Oscilloscope
Test point : TP1 (VA-191 board)
Setting point : 1 Lens IRIS
A
: A = 320 ±8 mV
Spec.
3. On the setup menu, set as follows.
PAGE : S12*FUNCTION 1/2
ITEM : TEST OUT
4. Equipment : Waveform monitor
Test point : TEST OUT connector
: 1RV201 (VA-191 board (G GAIN))
Adj. point
: B = 100 ±2 IRE (NTSC)
Spec.
B = 700 ±10 mV (PAL)
B
7-14
16:9 mode
CAM/ON
PRST
BLK
: 0
: 0
16:9
G
5. On the setup menu, set as follows.
PAGE : S12*FUNCTION 1/2
ITEM : TEST OUT
ITEM : GAMMA
6. Select portion C by using the waveform monitor.
7. Set the waveform monitor to the CHROMA mode.
8. Equipment : Waveform monitor
Test point : TEST OUT connector
: 1RV101 (VA-191 board (R GAIN))
Adj. point
1RV301 (VA-191 board (B GAIN))
Spec. : Minimize carrier leakage D by using
the variable resistors alternately.
Setting After Adjustment
. On the setup menu, set as follows.
PAGE : S12*FUNCTION 1/2
ITEM : GAMMA
A B
1
1
2
RV301
3
ENC
OFF
C
D
ON
D E
C
RV201
1
1
RV101
TP1
VA-191 board (A side)
DVW-790WS/709WS/707
DVW-790WSP/709WSP/707P P2V1