Quote:
Originally Posted by timmy
i went over all resistors unless i missed one but i dont think i did but these lines and rolling i cannot find whats going on here. i subbed tubes and changed resistor values around on the vert hold and vert size but no luck. if i shorten the pic top and bottom with the vert size it will become better stable but i cant widen the screen up and down because it goes crazy.
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First I want to apologize. I didn't click on your pic and look closely before assuming that you had retrace lines. Also, I agree if you have a nice, bright CRT you wouldn't want to dim it to the extent that it would take. Frankly, it's bad enough that I can't imagine dimming it making it better unless it was way dim where things are indistinguishable from one another.
I think you were in the right circuit from the get go and I agree with Eric. You have some nasty vertical linearity issues. I used your quote as I noticed (even yesterday) that you say that you "changed resistor values around." That concerns me a bit, but I don't think that you said that whatever you changed made anything worse, so maybe that's OK. It just sounds like you experimentally changed some values as opposed to correcting out of tolerance resistors.
Anyway, the problem is the reason you did that, so what is causing it? A good look at the shot makes me ask if the raster is folded over with the adjustment pot set way too high. That can give the widening traces for sure, but you see them upside down. Maybe a couple of things going on there as far as component issues and adjustment. If you recapped it then the safest thing to say is to check all of your solder connections really good and look for solder drips that have fallen and bridged something. Maybe go over your cap values listed in the schematic from what was installed. There might have been a mistake that took a while to damage a cap and to show its self on your screen
Don't waste your money changing more potentiometers. If you check pots out good with an analog ohm meter and you seen no issue; then there is very little way there can be one if any. Good luck with this! Can you post a pic of the set together and working. We all would probably like to see it. I know I would.