Did these tubes ever reach production?

 Hi, surfing the net I found and saved this (I don't even recall where). Does anyone know if these tiny tubes ever reached production or if they were standardized?

Regards!

Javier Albinarrate

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Hello Javier,

I sent the info in this thread to tube expert/historian Ludwell Sibley, and he identified it in this response to my email:

[snip]

If they're talking about a submin tube, four leads, body 17 mm long, with a
wire-rod anode and a U-shaped "grid" in the form of a 3/4 rectangle with a
hole in the middle, they may be talking about something called an SN-856-F.
(That sure sounds like a Sylvania developmental number from the '40s!)

That type got written up briefly in the "OTB" for March 1986. It "surely"
never reached commercial use. I have a couple of samples.

[snip]

Lud offered to give me a sample, once he finds it. I will then photograph it, measure it and post the results. The OTB is the Old Timer's Bulletin, which changed name to the Antique Wireless Assocination Journal.

Regards,

-Joe

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That is really amazing! As I assumed that these never reached commercial production, it seemed obvious that they faded in the midst of time... but instead, not only somebody clearly identifies them.. but he has samples too!

Thanks for the enquiries Joe!

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Hello Javier,

The tube that Ludwell identified is actually a gas Thyratron. So it could not have been used for linear amplification.

See details at SN-856-F

Regards,

-Joe

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Hi Joe,

What an amazing and detailed job! Yep, certainly any tiny thyratron use has really huge chances of being involved with bomb fuses or missile development, but that would mean that the technology was there, and that the need for other tubes was there too. Unfortunately I doubt that such a lucky strike like this one (finding samples) can take place twice.

Regards!

Javier

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