Convergence and proper color level adjustment (long)

I've been trying to figure out for a while how to properly converge
monitors. All monitor manuals describe the basic dynamic and static
convergence, but they don't discuss how to apply magnets to correct minor
problems. Likewise, the WG6100 manual describes setting the bias and gain
of the colors, but it doesn't really explain how to get the bright and dim
lines "white". Below are my newly discovered (to me) answers. I hope this
is as interesting to everyone else as it is to me. As simple as this is, I
hope I'm not the only one who didn't understand.

Convergence correction: You have probably seen magnetic shunts glued
underneath monitor yokes. I was trying to figure out how the placement of
these shunts affected the display. Apparently, they are not meant to
correct problems in the corners. They are only used to correct problems at
the top, bottom, left and right. They are placed under the yoke to make
corrections in the initial deflection. The placement is an art, as you
need to move them around to find the sweet spot.

As far as the corners are concerned, there are some chevron shaped magnets
that you apply further out on the tube to affect the deflection just before
hitting the phosphors. Again, there is a sweet spot that you can only find
by moving the magnet around.

With these two techniques, it should be possible to converge the entire
screen. I'm not sure where you buy the magnets or what the best way is to
secure them, but this is how its done none the less.

Color level adjustment: I didn't like the way this has been described. You
are instructed to adjust the bias to set the dimmest white line to pure
white. Likewise, the gain is adjusted to set the brightest white line to
pure white. What I have found to be the best way to do this is the following:

1) Adjust the bias and gain knobs so the colors are the brightest (the
black and white pots are turned in opposite directions to acheive this).
2) Adjust the screen control until the dimmest white line barely has any
visible color (typically only one or two of the three colors is left visible)
3) Adjust the black knob for the visible color(s) until the color just
disappears. The line should not be visible at all.
4) Repeat steps 2 & 3 until all three colors appear and disappear together
when adjusting the screen control.
5) Adjust the screen control until the brightest white line barely has any
visible color.
6) Adjust the white knob for the visible color(s) until the color just
disappears. The line should not be visible at all.
7) Repeat steps 5 & 6 until all three colors appear and disappear together
when adjusting the screen control.
8) Repeat steps 2 through 7 until the colors seem to be in sync for both
the brightest and dimmest white lines. They are all now pure white.

These steps ensure the brightest vectors with the proper colors without
showing retrace lines. I'm not sure why I didn't originally associate
these steps with the description provided in the manuals, but it seems to
make perfect sense now. Go figure.

For what its worth, I'm going to make a more descriptive document and put
it online. I just thought I'd run it by you guys first. If you would,
respond to me privately and let me know if this helped you or if you
already knew this. I'm curious to see if I was the only one who didn't
really understand this process.

Jon
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Received on Sun Nov 12 09:35:35 2000