Time to get this site upgraded, so we are passing the hat around. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html
Go to Page...
We appreciate your help
in keeping this site going.
I'll have to look at the schematic when I go back to the basement later...I didn't check what it went to only that it could cause CRT bias issues that you were experiencing. I think video was cathode driven so the grid cap could be something like a retrace blanking circuit... I'll get back to you.