Specifications

Page 35
Purpose:
Measuring
Instrument
Test Point
Measuring
Range
Input Signal
Ext. Trigger
Input Terminal
Symptom:
Purpose
Measuring
Instrument
Test Point
Measuring
Range
Input Signal
Ext. Trigger
Input Terminal
Symptom:
MODELS: WT-46807 / WS-55807 / WS-55857 / WS-55907 /WS-65807 / WS-65857 / WS-65907 / WS-73907
To set the cutoff point for all three CRTs.
Monochrome has a color tint, or incorrect brightness.
[CRT Circuit]
7. CRT Cutoff
Oscilloscope
TP6R, TP6G, TP6B
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50V/Div. 2msec/Div.
None
Video Input
Note: Use the Expand mode (full screen)
(Refer to page 29 for Test Point locations.)
1. Select an External Input with no signal.
2. Enter the Adjustment Mode, Video/Chroma Function.
3. Set the data to the values given in the table below.
4. Connect the oscilloscope to TP6R.
5. Adjust the Red Screen VR so the black level is 190V, as shown below, or
199V ±1VDC using an DC Voltmeter.
6. Repeat Steps 4 and 5 to set the Blue and Green Screen VRs, using
TP6G and TP6B.
Note: White Balance must be performed after this adjustment.
VIDEO / CHROMA Function
Item # Abbrev. Data
1SCT42
2SBRT18
5SCON2
6RDRH42
7GDR50
8BDRH42
9CTRH15
10 CTGH 50
11 CTBH 15
18 BRT 31
19 COL 0
CIRCUIT ADJUST MODE
Activate …….. MENU-8-2-5-7
Function …...………..AUDIO
Item No. ……….…….VIDEO
Adjust Data ….…….ADJUST
Save Data …. ………ENTER
Exit …………..MENU (twice)
DC Voltmeter
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NTSC White Raster
RF or Video
[CRT Circuit]
8. White Balance (NTSC)
To set the CRTs white level in the NTSC mode.
Monochrome has a color tint.
Note: Use the Expand mode (full screen)
1. Supply a full White Raster Signal
2. Activate the Service Mode, Video/Chroma function.
3. Set the data for Item “19 COL” to 0.
4. Adjust Items “6 RDRH” and “8 BDRH” for optimum white at the center of
the screen.
5. Reduce the input luminance level to 25%.
6. Adjust Items “9 CTRH” and “11 CTBH” for optimum white.
7. Insert a Milliammeter in series with each CRT Cathode. The maximum
allowable current for each CRT is given in the table below.
8. Set the white raster to 100% and adjust Items “12 RDRL” and “13 BDRL” for
optimum white at the center of the screen.
9. Reduce the luminance level to 25%.
10. Adjust Item “14 CTRL” and “16 CTBL” for optimum white.
11. Set the data for Item “19 COL” back to 28.
Maximum CRT Current
CRT All Except Only
WS-73907 WS-73907
RED 580 uA 900 uA
GREEN 580 uA 900 uA
BLUE 580 uA 900 uA
CIRCUIT ADJUST MODE
Activate …….. MENU-8-2-5-7
Function …...………..AUDIO
Item No. ……….…….VIDEO
Adjust Data ….…….ADJUST
Save Data …. ………ENTER
Exit …………..MENU (twice)