On the bench: 1953 Raytheon Vu-Matic 21" TV

[DavGoodlin]

Originally Posted by dieseljeep

Antronic made them as well. If it's an isolation brightener, it would say on the unit.
I would try the separate transformer trick, as suggested by others.

Vid-Aire made one with a plug that selected between series or parallel filament strings, I dont think it isolated.

I had a 1958 Motorola series-heater set with an intermittent H-K short in its 21CBP4. The short made it go washed-out negative with retrace lines.
After I isolated the CRT filament with a perma-power brightner, video just got a bit smeary when it shorted.