Re: Rotary gaps

From: Esondrmn-at-aol-dot-com
To: tesla-at-grendel.objinc-dot-com
Subject: Rotary gaps

es>I am planning to build a rotary gap and would appreciate any suggestions or
es>comments from those who have already done this.

es>I am planning to use a 12.0" diameter nylon disc probably 3/8" or 1/2" thick.
es> If I remember what I've read, my first choice for electrodes should be
es>tungsten, then brass then copper.  Is this correct?  I can only find tungsten
es>in 5/16" dia.  I think it is available in up to 3/8" but I haven't found any
es>yet.  I was thinking that I wanted about 1/2" dia. electrodes.  Any comment?

Hi Ed (great name),

	Uhm... some of you all probably know this already, but tungsten rod 
is sold as inert-gas welding rod. I have seen up to 1/4" stuff from 
Mcmaster-Carr (expensive). Richard Hull has used 1/8" THORIATED tungsten 
rod for one of his rotarty gaps. Thoriated tungsten is also a common 
welding rod material and is used as a decent thermionic emmiter in vacuum 
tubes (better than plain tungsten). I assume that's why Hull uses it: it 
should have lower resistance for a given current/voltage. Or higher "Q" as 
Mr. Quick would say :)!