Thread: AC In My B-
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  #34  
Old 01-12-2021, 03:15 PM
Jon1967us Jon1967us is offline
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Join Date: Nov 2018
Posts: 350
Quote:
Originally Posted by old_coot88 View Post
At this point I would do this: Locate the .05 cap which goes thru a 180K resistor to pin 5 (plate) of the 6AU6 sync separator. Disconnect that cap. This completely decouples the sweep oscillators from the video chain, leaving them free running.

Then you have to manually jockey the hor and vert holds to hang onto the pic. See if the hula'ing is still present. If it is, then the ripple is not originating in the video chain but in the sweep area.
Per your suggestion I tried this. First video is with that cap disconnected...

https://youtu.be/QG5jBrWuftQ
https://youtu.be/EvWDVbtS3_o

Comparing a few times, no cap connect vs connected, there actually doesn't seem to be much difference other than when the cap isn't connected there's less vertical stability.

Last edited by Jon1967us; 01-12-2021 at 04:12 PM.
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