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Re: Spark Gap Design Alternatives



Tesla List wrote:
<SNIP>
> 
> 1. Would the nylon stand up to the heat?  If not, is there a suitable
> material I could find threaded (or thread myself)?

I don't think nylon will stand up, but I don't know it's properties
concerning
heat. Phenolic insulating material comes in long "tubes" and would stand
the heat
much better. It can be threaded much like threading a piece of hardwood.
I can try
to get a source supplier's address from work, if you like.

> 
> 2. Would the 1 inch diameter and length be enough for good heat dissipation?
>    Would other proportions be better?

Heat dissipation would, of course, depend on run time, but more and
closer
gaps would go much further toward dissipation than larger size. No
matter
how big a surface (to a point) the surface itself will get extremely hot
and
begin to ionize before the rest of the material gets hot. The increased
number
of gaps at a smaller gap space will spread the load over a much greater
surface
area and decrease point heating.
> 
> 3. Which would be better, brass or copper?

Brass doesn't oxidize as easily as copper, but it has a higher
resistance. It' a kind
of trade-off depending on how you use it.
> 
> 4. Would the individual disks be likely to rotate (get out of adjustment)
> during use?

Yes. The discharge creates an acoustic wave which will cause vibration
in the
disk assembly. You would need a very tight-fitting thread and even then
it
might work loose. Alternately, you could place a small disk of
insulating
material between the disks to maintain spacing. These would probably be
hard
to make, and I don't know what material would stand the abuse. On the
other
hand, if you place this arrangement in a trough of some sort, you could
make
the trough a tight enough fit that the disks couldn't turn.
> 
> 5. Any other problems or considerations?

I'm concerned (from what I've read here) about the small number of gaps.
It has been said many times on this list that more gaps means better and
smoother performance. Of course, if you are going to use the threads of
the
center rod for spacing adjustment, it would need to be a very fine
thread.
> 
> Thanks for any comments or ideas!
> 
> Tedd

Thanks for sharing what seems a good idea. If you decide to go with it,
please let us know how it works.

-- 

	Rick Holland
	
	The Answer is 42.