Vacuum Tubes 1943 Educational Documentary WDTVLIVE42 - The Best Documentary Ever

Too bad WDTVLIVE42's channel was taken down.

I wonder if there's a higher resolution version of this video.

nive

I always wondered what the 90 volt battery was used for, now I know. I remember them back in the 1970''s made by Eveready. I knew then it was not a good idea to stick your tongue across the terminals to see if it was good or not.

I love these old documentary’s