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From: gin@stcvax.STORTEK.COM (George Noyes)
Newsgroups: sci.electronics
Subject: Re: Has anyone made any homemade valves (tubes), semiconductors ...
Summary: getters
Message-ID: <367@stcvax.STORTEK.COM>
Date: 30 Jul 90 21:49:56 GMT
References: <872@massey.ac.nz> <37291@shemp.CS.UCLA.EDU> <10368@crdgw1.crd.ge.com>
Organization: Storage Technology Corp.  Louisville, CO
Lines: 20

In article <10368@crdgw1.crd.ge.com>, perley@galaxy (Donald P Perley) writes:
> In article <37291@shemp.CS.UCLA.EDU>, cccph@eel (Charles Hobbs) writes:
> >In article <872@massey.ac.nz> GMoretti@massey.ac.nz (Giovanni Moretti) writes:
> 
> >You could do this successfully if you had some way of getting a  
> >good vacuum. (Commercial valves have chemical compounds known as
> >"getters" which aid in removing oxygen from the valve)
> 
> I'm not sure what is in the getters.. maybe those could be homebrewed
> as well?
> 

"Getters" - typically barium, sometimes cesium or other metals that 
are highly reactive to oxygen (and sometimes nitrogen).
Magnesium and "Lime (Calcium carbonate)" have been used in antique
(pre 1930) tubes.

fyi

george noyes, W1XE