On Monday, July 17, 2017 at 2:25:37 PM UTC-5, Ian Field wrote:
jamesgmail.com wrote in message
news:1a527a6f-6b49-454e-8fa1-dd1f71088fc4googlegroups.com...
I need help

If its that bad - you probably need to sort out the purity first.

I didn't think RCA PIL tubes still had those.

What is a PIL tube ?

The PTK series is rear projection, if a regular CRT it is CTC. The CTCs in regular direct views do not have any convergence in the menus, it is all done with rings and actually sometimes they don't even have them. They have a magnetic strip. It can be adjusted but is hard to get perfect. They also had bonded yokes so convergence adjustments were limited as well.

At the factory it was adjusted before the glue dried on the yoke, and they probably had a selection of different magnetic strips. I am also pretty sure they were adjusted by machine.