[Penthode]

Hi All,

This weekend I began working on the CT100 again. The set was working fine through the weekend until the picture began to jump. It looked like a focus problem I cautiously powered the set. As I adnance the focus pot a dreading popping started and the higher the voltage the worse it would become.

Looks like the convergence transformer is open internally at the secondary brown lead from the focus pot. Between Blue and Yellow it measures 21kohm and the primary is okay.

I suspect a break internally due to the pitch potting. Might be lucky and be able to find the break at the connection to the brown lead.

The transformer looks like it has been replaced once in the life of the set from the look of the soldering: the replacement is a silver canned transformer.

I recall a couple of decades ago, John Folsom and others discussed rebuilding the transformer. Are any spares around?

(The transformer failed Sunday evening (December 17) which I recall was the day exactly 70 years ago the FCC adopted the NTSC standard!)

Any help or anecdotal experience regarding this problem will be greatly appreciated.