Re: New sparkgap

From: 	Bert Hickman[SMTP:bert.hickman-at-aquila-dot-com]
Sent: 	Thursday, June 26, 1997 9:25 PM
To: 	Tesla List
Subject: 	Re: New sparkgap

Tesla List wrote:
> From:   Richard[SMTP:esmit-at-ilink.nis.za]
> Sent:   Thursday, June 26, 1997 3:05 AM
> To:     tesla-at-pupman-dot-com
> Subject:        New sparkgap
> Hi, there
> Well, last night my brain had worked overtime and I might have found two
> sorts of sparkgaps that will work.
> Here it comes!
> Fig.1
> -----
> In figure 1 you have the same sort of spark gap as Richard Quick's. The only
> thing that is differant is it has a center electrode and one on the normal
> pipe electrodes. The center electrode is made so that it can turn around 360
> degrees
> , thereby you can change the length of your sparkgap that the spark should jump.
> The center electrode works almost like a meters needle.
> --------------------------------------------------------------------------------
> Fig.2
> -----
> In figure 2 you have a sheet of say thick piece of polyethylene or something
> that will withstand heat and is flexible. You make a cylinder of it and
> mount the electrodes(cuper pipe) so that they touch each other. You have to
> screw the pipes against the sheet or make it in any manner fast so that it
> sits tight.
> If you want to change the sparkgap all you have to do is make the cylinder
> diameter bigger. When you make the diameter bigger with the help of that
> extra piece of sheet you see in fig.2 your electrodes will move away from
> each other, so I think it is a wonderful sparkgap because you can change the
> distance between electrode.


The second approach you've proposed is really quite clever! However, the
flexible material would need to be heat resistant, have high insulating
capability, and yet be flexible enough to be rolled into a circle.
Polyethylene wouldn't do it, since it softens at rather low
temperatures. Thin sheets of G10 or Kapton sheeting might work however.
Every now and then I run into thin insulating materials for sale at
hamfests (typically for flex-circuit work). The idea of using an
adjustable diameter sounds like a new idea... congratulations!

Fr. McGahee also has recently developed a very interesting adjustable
static gap design using copper pipes arranged in adjustable
parallelograms. This system, or even an in-line fixed vacuum gap will
have better quenching capability they both use a high power vacuum
cleaner motor to pull in cooling air through the variable gaps. 

Safe coilin' to you, Richard!

-- Bert H --