Re: 2 foot sparks

From: 	Peter Electric[SMTP:elekessy-at-macquarie.matra-dot-com.au]
Reply To: 	elekessy-at-macquarie.matra-dot-com.au
Sent: 	Friday, July 25, 1997 6:21 AM
To: 	Tesla List
Subject: 	Re: 2 foot sparks

Tesla List wrote:
> From:   Alan Sharp[SMTP:100624.504-at-CompuServe.COM]
> Sent:   Wednesday, July 23, 1997 6:56 PM
> To:     INTERNET:tesla-at-pupman-dot-com
> Subject:        Re: 2 foot sparks - need more garage!
> John,
> >Your spark gaps are probably quickly overheating after you turn on
> >the system, the quench is degrading and output sparks weaken.
> >You can try using some sort of fan or air blast to cool the gaps, or
> >use a greater number of gaps...if you haven't already tried this.
> >John Freau
> Yes, I'm using 5 pieces, 3" long, of 2" diameter copper pipe
> set very close as a spark gap. I tried a fan as you suggested
> and it helps. I'm looking for an old hairdryer or a vacume
> cleaner for an air blast.
> Next I'm going to rebuild to make it more portable and try
> building some capacitors. Probably using tin foil, stuck
> with varnish to 2mm clear polystyrene. This should hold at
> 7500V AC even without oil - I hope!
> But I think its quite big enough! I don't really have the
> room at home for a bigger coil.
> Then I think I'll go back to solid state coils - more manageable.
> Later I'll try a valve coil - then I'll really need your help, John.
> Someone was asking about my transformer - sorry but it was a one off
> surplus from a physics dept, no more caps either.
> Have fun,
> Alan Sharp (UK)

Yes, I was asking about the tranny, shame about that as they are not so
easy to come by here in Aus either.

I have a tip for you re quenching of the spark gap. I found that two
squirel cage fans from old microwave ovens work a treat. You place one
blowing forward towards your gap and and place the other one sucking at
the back (if you know what I mean). I used 6" plumbing pipe to house the
gap and hot melt glue makes it really easy to mount the fans.

I found this works just as well as quenching using a compressor at 20psi
with out the big hassle of running the compressor.


Peter E.