Re: Vacuum jar rotary spark gap / thyratron (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 17 Aug 2007 10:18:14 +0000
From: Sparktron01@xxxxxxxxxxx
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Vacuum jar rotary spark gap / thyratron (fwd)

Gary

Not true.

Richard Hull in our early experiments used a 15kV vacuum bottle
out of some GE switchgear as a single point VSSG (vacuum
static spark gap).

It electrically worked fine (gap was in the 1-2mm range).  Problem
was the assembly got hot as a bit$$ because there was no way
to keep the assembly cool (you only have metal conduction
up power contacts to keep gap assemblies cool).  This thermal
problem occurred with power input in the <1kW input range
IIRC.  Eventually you would compromise the vacuum seals
then you would have basically a normal static gap with air
dielectric.  FWIW.

Regards
Dave Sharpe, TCBOR/HEAS
Chesterfield, VA. USA

<SNIP>-------------
> >
> > ---------- Forwarded message ----------
> > Date: Thu, 16 Aug 2007 16:07:35 -0400
> > From: "Lau, Gary" <Gary.Lau@xxxxxx>
> > To: Tesla list <tesla@xxxxxxxxxx>
> > Subject: RE: Vacuum jar rotary spark gap / thyratron (fwd)
> >
> > The biggest problem with a gap in a vacuum is that air is a necessary
> > component of a spark gap.  It's the plasma between the electrodes that
> > conducts the current through the gap.  No air, no plasma, and no
> > current.
> >
> > If your spark gap is louder than the sparks coming off your top load,
> > then something is seriously wrong.  There's no such thing as a quiet
> > coil.
> >
> > Regards, Gary Lau
> > MA, USA
> >
> >> From: Timka <tomasdoc2002@xxxxxxxxx>
> >> To: tesla@xxxxxxxxxx
> >> Subject: Vacuum jar rotary spark gap / thyratron
> >>
> >>
> >> Anyone tried before to make a vacuum jar rotary spark gap?
> >>
> >>   I have a nice deep vacuum pump and I'm thinking to make a rotary
> > spark gap
> >> using 10,000 rpm hard drive motor with attached tungsten electrodes.
> > Everything
> >> will be assembled and placed under a thick and large plastic jar from
> > which I would
> >> pump all the air away.
> >>
> >>   Since that motor is DC I can change RPM with voltage and it also has
> > a nice Hall
> >> sensor build in, which I can use to monitor RPM with external meter.
> >>
> >>   I'm doing it because I'm tired of spark gap noise, so I think that
> > if I create above
> >> mentioned enclosure it would help to ease stress to my ears.
> >>
> >>   Any suggestions and constructive criticism would be extremely
> > appreciate