I have a 12" zenith porthole with a 12up4 metal shell crt. I sent it off to Hawkeye to be rebuilt but Scott is reluctant to do it because of a very high failure rate on metal shell crts.

A while back I read an article somewhere about someone who substituted an all glass crt in place of the metal shell crt in a Zenith porthole but I cant locate the article on the internet anymore.

Does anyone rmember that article and have a link to it?

Thanks,
Bob Galanter

iirc a 12fp4 will sub.

I cant find any data or any references to a 12fp4 Is this an all glass or a metal shell?

Thanks,
bob

I also have a Zenith Porthole that uses the 12up4 CRT. I been looking for one on ebay for awhile to try to fine one. The 12up4 CRT that I have has very low emission.

Ross

I cant find any data or any references to a 12fp4 Is this an all glass or a metal shell?

Thanks,
bob
all glass.
i remember buying 4 of them at ft wayne a few years back and one wound up in a zenith porthole.