Wells-Gardner D9100 - Manual (Page 14)

7-3.8 Purity and Convergence Adjustment (continued)
⑧ Check the purity of the red and blue raster by adjusting the bias
controls.
⑨ Obtain a white raster, referring to “CRT GRAY SCALE
ADJUSTMENT”
⑩ Proceed with convergence adjustment.
2. Convergence adjustment:
① Change to a crosshatch pattern with a color signal generator.
② Adjust the BRIGHTNESS and CONTRAST controls for well
defined pattern .
③ Adjust two tabs of the 4-pole magnets to change the angle between
them and superimpose red and blue vertical
lines in the center of the picture screen .
④ Turn both tabs at the same time keeping their angles constant to
superimpose red and blue horizontal lines at the center
of the screen.
⑤ Adjust two tabs of 6-pole magnets to superimpose red/blue line
with green one. Adjusting the angle affects the vertical
lines and rotating both magnets affects the horizontal
line.
⑥ Repeat adjustments 3,4 and 5, keeping in mind red, green
and blue movement, because 4-pole magnets and 6-pole
magnets interact and make dot movement complex.
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