I do think one possible area of unexplored power-microwave tube
development might be a space-borne sun-heated filament magnetron or
something. Big collector on one side, fins on the other.
I'm not a tube nut, I just researched them for various projects. I don't
believe in illuminati conspiracies and 100 mpg carburetors either!
tomj
On Wed, 2004-01-21 at 01:31, Stan Barr wrote:
> Hi,
>
> William Donzelli <aw288_at_osfn.org> said:
>
> > > ...this sounds as though it's the converse; this sounds as though tube
> > > transit times are inconveniently _high_.
> > >
> > > So I don't get it.
> >
> > In theory, computing tubes would not use much power at all, so one could
> > space the cathode-grid-plate structure very close, and get the super
> > speeds due to the very short distances involved. Imagine tubes as small
> > today's transistors - the speeds would be fantastic, as the electrons
> > would speed right thru the micron of vacuum much faster that a micron of
> > silicon.
> >
> > However, the real world hits the tubes far before element spacing gets
> > this tiny. The breakdown voltage between the cathode and plate probably
> > hits first - too close, and the electrons will simply jump over on their
> > own, like a spark. Likewise, with very short distances, capacitance will
> > become a big issue. The best conventional tubes top out somewhere around 4
> > GHz, and these were only good for small amounts of power. They were a
> > bastard to build, as well.
> >
> > So, in a perfect world, with no capacitance or power problems, tubes
> > would be great.
>
> See http://www.triodeel.com/area51.htm - if it still works.
Received on Thu Jan 22 2004 - 19:25:31 GMT