GE 800D restoration

[bandersen]

I found a bad mica coupling cap between the 2nd and 3rd IF stages. The associated plate resistor was cracked and more than 50% low.
Replacing both improved gain and sync stability a bit, but vertical hold is still very difficult to maintain.



I'm also trying to eliminate the bright vertical lines and poor horizontal linearity.


The driver trimmer doesn't seem to do anything and is off center from the chassis hole. It all appears to be original though with the exception of the fuse holder.





I unmounted it and it does test good and is adjustable over the correct range. All the surrounding components test good as well.

I'll bend the mounting bracket, remount and try again. Then get a scope on the HOT grid and make sure the drive signal varies as I adjust the capacitor.

This is proving to be a challenging set to work on.