Very much On Topic: Integrated Vacuum Tubes

Stan Barr stanb at
Thu Apr 21 03:06:22 CDT 2005


William Donzelli said:

> > - What was/is the smallest tube? purpose? 
> RCA's Nuvistor - a family often found in late 1960s TV tuners and some
> test equipments. They are almost always triodes, and are really small -
> 3/4 inch long, maybe 3/8 inch diameter, all metal. RCA made a few half
> sized Nuvistors, but never sold them.
> Sylvania also made some subsubminis - tubes in T1 bulbs, but they never
> sold either. A T1 bulb is 1.8 inch in diameter.

There were some very small wire ended ones made for proximity fuzes in
anti-aircraft shells.  They are about the size of one of those small 
neons.  Someone in the USA has a stock of new ones and I wouldn't mind 
getting a few to play with, but I've lost his address.

Back in the '60s I had a little portable radio that used wire-ended
valves/tubes about half an inch diameter and an inch long.

There were also some vacuum tube ics being produced experimentally a
few years ago with a few hundred planar devices in one package.

Stan Barr  stanb at

The future was never like this!

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