RE: brass or tungsten (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 9 Jul 2007 12:44:56 -0400
From: "Lau, Gary" <Gary.Lau@xxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: RE: brass or tungsten (fwd)

The answer would depend on the power level you anticipate running with.
With a 15/60 NST, my 5/32" Tungsten rod is just beginning to show some
wear.  If you are running a smaller PSU than this, you could probably
get away with brass.  Larger and I would definitely stick with tungsten.
Tungsten is a fairly good electrical conductor, and the resistance
across a 8-9" length is negligible relative to gap losses (and I don't
think that plating would make any difference).

But really, the beauty of a propeller gap is the relative ease of
electrode construction.  The rotating rod is used as-is out of the box,
and the stationary electrodes are non-critical in length.  A Dremel tool
cutting wheel easily cuts the rod.

Regards, Gary Lau
MA, USA

> Date: Sun, 08 Jul 2007 20:28:00 -0400
> From: Scott Bogard <teslas-intern@xxxxxxxxxxx>
> To: tesla@xxxxxxxxxx
> Subject: brass or tungsten
> 
> Hey everybody,
>      A quick question, would I be better off using a tungsten rod or a
brass
> rod in a propeller rotary gap?  my thinking is that tungsten would be
able
> to withstand the heat better, but it is expensive and fussy to work
with,
> and brass would conduct better and be cheaper, and I could get it in a
> bigger diameter (making it last longer because of improved heat
> dissipation).  When it wears out, I can just move the stationary
electrodes
> in to compensate.  I'm just looking for other opinions, and maybe if
> somebody has done some experiments, that would be cool.  Thanks a
bunch.
> Scott Bogard.