Re: Tech: I can't get proper focus on Tempest

Clay 77 wrote:
>
> >The monitor has been completely rebuilt and capped. It works fine
> except I
> >can't get the focus to stay right. I have tested the HV board and
> deflection
> >pcb in another unit and they work perfectly. All power transistors are
> good.
>
> ****When I rotate the focus knob, the picture will gain focus
> momentarily.****
>
> Kirby,
> This exact thing happened to me with my MH conversion...frustrating as
> hell. John Lee and I went and changed everything on the chassis and
> nothing helped. We then swaped in a different tube and viola!
> Apparently, there is a screen on the inside of the tube where the image
> is focused on, and on my tube this screen was loose and/or damaged. I
> don't recall all the technical details but suffice it to say that the
> tube was the problem. Good luck.
>
> -Clay Smith
>
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Hi, all!

It could also be a bad focus resistor. If you have a high voltage probe,
read the focus lead and see if it is stable...otherwise it is the tube.
Check connections for the monitor ground, the focus/screen control
ground, and any resistors on that return path for the focus control.

John :-#)#

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