Re: Rotary Spark Gap Design

To: tesla-at-pupman-dot-com
Subject: Re: Rotary Spark Gap Design
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
Date: Mon, 20 May 1996 07:54:17 +1200

Hi Skip,
        You replied....

> > > 3. Resonance - Secondary coils are highly resonant, as everyone
> > > here has witnessed. Xmsn lines are, by definition, wide-band and
> > > therefore non-resonant.
> > 
> > I think that is only true when the line is terminated in it's Zo at
> > each end making it a matched line. A piece of coax (for example) that
> > has any other termination or is shorted or o/c has a high VSWR and is
> > highly resonant (Y-N)? We had a problem here where a 50 ohm data link
> > cable had a piece of 75 ohm coax added in by mistake. Reflections and
> > high VSWR meant the link failed totally. I designed a 1.2:1 line
> > matching transformer to correct this problem, one inserted at each end
> > of the 75 ohm cable.
> >     I think your model of a sinusoidal voltage/current distribution is
> > actually quite accurate.
> > 
> > Malcolm
> 
> Malcolm and Greg
> 
> Don't we really want a transmission line with a large vswr with the max 
> point at the top of the coil?

Absolutely! In fact the system is highly mismatched when not sparking
and rarely get a perfect match. I have done a weekend of experiments 
that show this clearly and also have measured my way to a choice of 
primary configurations with quite different virtues. Will post later 
on this.

Malcolm