1966 Mag: Build NE-2 Neon Bulb Computer - scan available

[Bob Bradlee]

On Fri, 27 Jul 2007 13:04:22 -0500, John Foust wrote:

>At 07:50 AM 7/27/2007, William Donzelli wrote:
>>The idea behind the getter is to clean up and gas that might be
>>trapped in the metal elements during pumpdown. A getter is really not
>>to clean up gases that sneak in thru the glass metal seals - the
>>getters just are not that effective, and as any plumber will tell you,
>>leaks only get bigger.

>Hmm, that reminds me of a lingering question in my mind.
>As a kid, I remember harvesting tubes from dead TVs behind
>the repair shop.  Breaking the tube, there was often a ring
>at the top, U-shaped in cross-section.  I seem to remember
>that they were filled with a powder that reacted with
>water, fizzing.  Am I mixing up this smell-memory with playing
>with calcium carbide?  What were common getter chemicals?

>- John


Very early tubes used magnesium, Scientific American had a great project using a Model T ignition coil to 
turn one into an X-Ray source which refered to them as being old way back then. Long before the artical 
was printed had switched to gallium as it did not radiate. 

A quick google found it here : 
http://www.noah.org/science/x-ray/stong/

Have fun :)