Raytheon Subminiature Tube Video

[Todd, KA1KAQ]

Preserved and provided by John Forster, and Debbie Douglas at MIT:

"A few years ago, Norm Krim, the pre-WW II developer of the Raytheon line of sub miniature tubes, gave me a copy of a video made, by the MIT Industrial Liaison Office, just before the last production line for those tubes in Quincy, Massachusetts, closed down.  With many thanks to Debbie Douglas, Curator of Science and Technology at the MIT Museum, that video is now available for viewing on MIT's Tech TV"

http://techtv.mit.edu/file/1125/

Originally designed for hearing aids before WWII, made famous later by the Proximity Fuze. A 15 minute clip, nicely balanced and very well done. Some interesting shots of early tubes, gear, and the big names from Maxwell to Marconi and Armstrong (monkey boy is in there too). Has excellent footage of the ladies on the line building the last of these tubes in 1986. No gloves or clean room here!

[W3RSW]

Very nice video.  I kept thinking of the contrast of Raytheon's manufacturing methods compared to the Frenchmen making his own on the Utube video we saw awhile back.

I see it was produced in '86. Jeeze, that seems like only a few weeks ago. - Probably cases of minatures still laying around somewhere.

Be nice to round up some of them and build up a single conv. BC superhet.  I guess the size of high impedance IF cans would be the deciding factor since dual, variable caps and small loopsticks that serve the transistor market already exist.   

   Boy, wasn't that a mouthful of time confused language?   -The latest serving the earliest.

What kind of IF transformers were in the mil. handi-talkies? Guess I'll have to look it up.

[w4bfs]

thanks Todd ... interesting history

[Mike/W8BAC]

Nice video. I am also surprised that production lasted until 1986. Than again I still tested and bought tubes at the drug store until the early eighty's.

The latest Crosley biography published two years ago detailed Crosley's work during world war II. The company was deeply involved in the development of the proximity fuse. Security was as tight as the atom bomb effort.

According to the book federal agents went with every shippment of munitions. Armed guards watched over stockpiles 24/7. Each and every spent shell had to be accounted for and tamper proof seals guaranteed each shot was fired and not stolen.

Mike

[Todd, KA1KAQ]

I don't recall which company now, but one US manufacturer was still producing tubes into the mid-90s. I remember there was a story in the Antique Radio publication about its closing. IIRC, they were located in Owensboro, KY? Maybe Louisville?

Also seem to remember that an overseas (Russian or maybe Chinese) company bought the equipment and moved it all over there to continue production.

The sub-minis are great tubes, low voltage and last a long time. Pretty sure they were used in the RS-6 and other covert gear, kinda surprised they didn't see more service in radio gear. Must've been the solder-in leads that scared folks.

[W3RSW]

I saw in the video where the tube leads in the mini-hearing aid went to a small screw terminal block.

Remember when transistors of the 2n112 variaty had sockets?  Still have some of them around somewhere, little tan babies with about 3/16" solder pins and phosphor bronze looking pin clasps.

What with what I knew about transistor biasing for pnp's back then ...  I needed sockets 

[w8khk]

Reminds me of all the time I spent in the AF working on the Phantom F4C/D Weapons Release Computer System - loaded with sub-mini toobs, but no transistors.  They did not come along until the E version.  Had to un-slobber and slobber in new ones, I wished they were in sockets, but that solution just would not fly!

I still have bunches of NOS 5702s, 6111s, and 6112s left over from my AF MARS days.  The 6111 and 6112 were almost equivalent to 12AT7 and 12AX7, IIRC.  Would be neet to use for a preamp in the base of a D-104, or maybe even a mini speech amp.  All hollow State!  Any takers?

[k4kyv]

Some subminiatures have all the wire leads coming out the bottom in a straight line.  But I have seen others with the wires coming out in a circular pattern, to fit into sockets much like regular miniature tubes.  I may even have some of the sockets "round here somewhere".

No doubt subminiatures would have become standard if silicon hadn't beat them to the punch.