[Chris K]

Originally Posted by old_coot88

Duh. Just found the schematic. Main B+ goes to pin 2 (damper) of the 33GY7. You could jumper an electrolytic from there to ground and see if it affects the distorted raster any. 47 mf or thereabouts.
https://antiqueradio.org/art/BK1077BSchematic2.jpg
https://antiqueradio.org/art/BK1077BSchematic1.jpg

Thank you for the links to the schematic!