Tuesday, February 3, 2009

Annealing molybdenum: the making of vacuum tubes

Wow! What a treasure is this old promo film (parts one and two, be sure to watch the "high quality" version, unless you have dial-up connection), titled "Electrons on Parade" for the making of RCA vacuum tubes of the 1940's. These are octal-based tubes. The first ones pictured are the very rugged metal-cased tubes frequently used by the U.S. military services. There is a HUGE amount of hand-work involved in the process. I never realized they had so much automation, even back in these days.

I found reference to the film being dated 1942. Early television transmissions are shown. The police cars are about 1940, I believe. And the ham radio gear in part two is really old. Brief review on the Web shows the electron microscope was invented in 1938. Failure to mention the war effort also seems to date the film as probably being created just before the war started.

For those interested in vacuum tubes, this is one of the best views of early construction I've seen and the only movie of that effort. Comments welcomed.


  1. It is amazing how much work was done by hand. The quality control, however, was very good with this method of manufacturing. Thanks for posting this.

  2. And little nitzy detail work that had to be done over and over and over. I think smacking gum would be the least of my responses to having to do that. I worked on an assembly line in Austin at one point. What a colossal bore! Thank goodness for KUT and earphones. Otherwise, I had to listen to about half dozen transistor radios, most playing country music hits. I'd solder about a thousand-plus solder connections a day. I'm not sure exactly how many. Speaking of hand work...