Rejuv tubes other than CRTs?
 

Looks like it might work, see
http://messui.the-chronicles.org/valves/EA199107.pdf
Though tubes like 6V6's are easily replaced... Not like CRTs.

Interesting read. For expensive audio tubes this is actually worth a try before laying down a wad of cash for new ones

Jefferson Electric made a tube rejuvenator for the old tubes like 01A's.
I don't know how well they worked on the old thoriated tungston tubes.

The thoriated filaments were supposedly more able to be rejuvenated than modern oxide cathodes. Since thoriated filaments are bright/high temperature already, I suspect its probably more likely for them to burn out in the attempt.

Never tried this, but I wonder if you'd be able to use an "activate" procedure on a tube to stir up a little life in it. Just turn up the filament voltage by 20% while it's on the tester.

If it's gonna hit the trash can anyway, seems like it'd be worth a try.

I did that with some 20's tubes (type 45s IIRC) and had mixed results....I believe I got an increase in emission, but the tubes were gassy.

I have done this with thoriated filaments with pretty good results. Some just burnout and others come way up in emissions. Not sure how long they would last in active service though.

Gregb

http://i452.photobucket.com/albums/q...pstf9i32hh.jpg

http://i452.photobucket.com/albums/q...ps9dmzvkev.jpg

http://i452.photobucket.com/albums/q...ps1lvtcir5.jpg

http://i452.photobucket.com/albums/q...pst1v4tvpo.jpg

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... :scratch2:

The connector shown on the unit is probably original and is called a plug cap. It would have been plugged into a plug body, which is the adapter having an Edison thread for a lamp socket, and a two-prong outlet for the plug cap. Many homes did not have any or many base receptacles in those days, and connections had to be made to drop light sockets. Where base receptacles were available, the plug body was removed. The tubes in question were used in the twenties in consumer radios but not afterwards, so this device was probably boxed up some time after that and never used again. There are instructions on line for rejuvenating tubes with thoriated filaments by other means, of interest to us today since those tubes become more rare every day.