Re: Vacuum Gap

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Kevin Ottalini by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ottalini-at-mindspring-dot-com>

Terry:
    I can confirm this experimentally.

I have a 4kw triode that has a broken filament.

So I set it up in place of my spark gap (grid/cathode  to anode) and
sure enough, it fired, with a very understated "tunk" (that was
0.125uFd at 8kv!), but after a few shots, I had to raise the firing
voltage higher and then after a bit still higher until eventually I
was up to 24kv and I could not get it to arc at all.

I presume that I was actually gettering out the stray gasses in the
tube, and when they were mostly gone ... no arc (at least at those
"low" voltages).

Still, fun to play with!

Kevin

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, August 17, 2001 8:43 AM
Subject: Re: Vacuum Gap


> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
> Hi,
>
> Reducing the air pressure will make the gap fire at lower and lower
> voltages until it is basically shorted.  At very low pressures (diffusion
> pump) the vacuum will act as very good dielectric and you will get no arc.
>
> I would think the gap resistance would be high at lower pressures.
Perhaps
> pressurizing the gap would have some advantage but "I" can't think of any
> advantage to a vacuum.
>
> Cheers,
>
> Terry
>
> At 06:12 AM 8/17/2001 -0700, you wrote:
> >Is there any significant improvement is performance in placing the the
> >spark gap in a vacuum?
> >I have a vacuum pump, and I was thinking of putting the SRSG in an
airtight
> >enclosure and sucking out the air. It would be easy enough to do, but I'm
> >wondering if it would serve any practical purpose besides giving me the
> >chance to put the unused pump to work...
> >
>
>