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  #16  
Old 09-04-2019, 01:22 PM
Kevin Kuehn's Avatar
Kevin Kuehn Kevin Kuehn is offline
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Have you checked that the AGC is working correctly? It almost strikes me as slight signal overload. Turning your signal generator output way down should verify.

Last edited by Kevin Kuehn; 09-04-2019 at 01:26 PM.
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  #17  
Old 09-04-2019, 01:29 PM
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The up and down wiggles on horizontal lines at upper left may be the yoke. (But I'm wondering why they aren't the same from top to bottom - maybe the pincushion circuit?)

The left and right wiggles at the top are probably just the horizontal AFC. (Reacting to non-standard sync from your cross-hatch generator? It would be interesting to check if you get the same result with a DVD source.)
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  #18  
Old 09-04-2019, 04:17 PM
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Kevin Kuehn Kevin Kuehn is offline
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Quote:
Originally Posted by old_tv_nut View Post

The left and right wiggles at the top are probably just the horizontal AFC. (Reacting to non-standard sync from your cross-hatch generator? It would be interesting to check if you get the same result with a DVD source.)
I experience that very issue with this Heathkit IO-101. Drove me about nuts trying to figure out the issue.

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  #19  
Old 09-04-2019, 05:23 PM
trinescope trinescope is offline
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The crosshatch is actually from a DVD that I made with a few test patterns on it. Some time later on I'll get a schematic for this and see if there are problems with the sweep waveforms. I did have to put in a new 36KD6 since the one that was in the set when I got it was broken.
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  #20  
Old 09-20-2019, 08:19 PM
trinescope trinescope is offline
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I finally found the problem, but don't have a really good fix at this time. The top core of the pincushion saturable reactor had fallen off and is lost. It was simply glued on when it was made. I did a "fix" from a few small ferrite cores glued together and then glued to the saturable reactor. The pincushion control has some effect now, just not enough. The problem is these transformers use a special core material that saturates easier than the ferrite I used, that's why I have only partial control at this time.
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