On Thu, 22 Aug 2019 09:02:25 -0700, Jeff Liebermann
wrote:

On Thu, 22 Aug 2019 08:54:59 -0700, wrote:

On Wed, 21 Aug 2019 17:35:58 -0700, Jeff Liebermann
wrote:

On Wed, 21 Aug 2019 16:47:10 -0700, wrote:

So I built a kit that uses an electrostatic deflection CRT for the
display. It all turned out very well except the display is much more
in focus on one side of the screen.

Is there an astigmatism adjustment? That's what's usually used to
tweak display for even focus.

Yeah, there is an astigmatism adjustment. And I adjusted it along with
the focus and brightness to get the sharpest spot.

Nope. That's not how astigmatism is suppose to be adjusted. It's
done with a horizontal trace across the screen. You adjust the
astigmatism knob so that the trace is consistent across the screen. If
you just adjust for the best dot, you end up with the focus and
astimatism controls fighting each other, especially since you can't
see what's happening outside of the dot area. Try it using a line and
see if it's any better.

What is weird is
that the display is sharpest on the left hand side of the screen and
then it gets more out of focus on the right. This out of focus is
gradual, with each number being a little more out of focus.
Eric

Well, there might be a component failure, but let's play with the
knobs a bit more first to see if things improve.
Well, I got time this morning to fuss with the CRT. The astigmatism
adjustment works but I cannot get the display to be as sharp on one
side of the tube as the other. I did degauss the thing too but there
was no change. Later today I'll swap the X axis wires and see if the
out of focus swaps too. If that happens then it must be the circuit
and not the CRT, right?
Thanks,
Eric