Rejuv tubes other than CRTs?

[Kevin Kuehn]

[Captainclock]

Originally Posted by Kevin Kuehn

It looks like on the box of this tube rejuvenator it originally had a light socket type plug on it which would probably date this tube rejuvenator to the 1920s, but it was then was later on replaced with a standard two prong plug, probably in the 1940s or 1950s seeing as the replacement plug end is made of bakelite...