RE: AMRAD Spark Gaps

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

Original poster: "Oxandale, Terry by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Toxandale-at-SPP-dot-org>

	The temperature rating was very low (I'm sure, because the
gaskets were designed to operated in an oil bath that I would expect
never see 50 degrees C. I only used them because they were soft enough
to crush and seal tightly, and because I had never built one and never
expected the large improvement over the stationary SG performance. The
pieces were pressed using (I'm going on memory here) a large washer on
top and centered over the brass disc and a smaller washer was centered
under the disc. the small washer OD was about 1/4" smaller than the
larger washer ID, thus when pressed, it formed a small round but flat
protrusion in the middle of the disc (again, like a dinner plate). If I
could find a high temperature plastic or fiber washers to seal these
"units", this thing would be worth redoing. It was interesting in that
when I would rebuild these washers, inspection of the discs revealed a
very uniform arcing pattern over the entire protruded portion (1.5"
diameter) of the disc. I did find that the expansion of the convex
surface did close up each individual gap a slight amount after warming
up thoroughly. I can look up the article date or send a Excel drawing of
the if wanted. It was a very simple device, and made with very basic
materials and tools, but worked very well. There is no telling how much
better a professionally designed one would work.

	Terry

> ----------
> From: 	Tesla list[SMTP:tesla-at-pupman-dot-com]
> Sent: 	Saturday, December 23, 2000 4:34 PM
> To: 	tesla-at-pupman-dot-com
> Subject: 	Re: AMRAD Spark Gaps
> 
> 
> 	Very interesting method of construction!  Overlooked that
> article.  Do
> you remember which issue?  Mine are not filed very well....  Any idea
> what temperature that gasketing material will withstand?  As you saw,
> I'd like to replace the gaskets in the gap I have and wonder if that
> would be suitable, and where you got it.  Running at about 600 watts
> the
> fins in this particular gap don't get too warm to touch, so suspect
> the
> temperature at the washers isn't very high either.  That's with
> convection cooling; should be much cooler with a small fan blowing on
> it.
> 
> 	If you made those plates on a press, seems to me it would have
> been as
> easy or even easier to use copper.  In thinking about it, I would
> suspect that with some fairly simple tooling one could crank the
> individual elements out pretty quickly, and sell kits for home
> assembly.   After looking at some of the workmanship on different web
> sites, think this would be childs' work for some of these guys,
> although
> perhaps they aren't interested in such low power operation.
> 
> 	On the general subject of quenched gaps, in the old publications
> one of
> the advantages of using them is said to be the fact that they could be
> used at much lower voltages than rotaries.  Might be interesting to
> follow up on that.
> 
> Ed
> 
> 
>