Secondary Formers

To: "'Tesla List'" <tesla-at-pupman-dot-com>
Subject: Secondary Formers
From: Tesla List <tesla-at-stic-dot-net>
Date: Sun, 23 Aug 1998 23:26:23 -0500
Approved: tesla-at-stic-dot-net


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From:  bertpool-at-ticnet-dot-com [SMTP:bertpool-at-ticnet-dot-com]
Sent:  Sunday, August 23, 1998 5:13 AM
To:  Tesla List
Subject:  Re: Secondary Formers



> 
> ----------
> From:  Mark Finnis [SMTP:mefinnis-at-medicine.adelaide.edu.au]
> Sent:  Saturday, August 22, 1998 7:38 PM
> To:  Tesla List
> Subject:  Re: Secondary Formers
> 
> At 16:09 22/08/98 -0500, you wrote:
> 
> >Forget the cardboard!!!!. The wall thickness is way to large and carboard is
> > lossy. Next problem if your secondary ever has internal arcing you can
> trash a
> > cardboarded one right away. Small coils (under 800 Watts input) can get away
> > with cardboard, but not yours!! You wouldn´t build a very successful coil
> with
> > it. If money is no object, try using plexiglas or lexan tubing. Your next
> bet
> > would be PP
> 
> While we are on the subject of formers (AGAIN !).  Managed to pick-up a
> nice little (hehe) piece of Med.Density PolyEthylene for a bargain price.
> Normally about $150US / meter and the off-cut cost me $12US.  The following
> shows this next to my first 6" coil:
> 
> 	www.cobweb-dot-com.au/dkfinnis/images/coil2_former.jpg
> 
> I figured MDPE would be good, as we use LDPE for HV caps etc.  Cut a piece
> off and put it in the MW oven on high for 1 minute with no heating evident.
> 
> My only concern is have noted in various posts:
> 
> 	increased wall thickness = increased losses
> 
> Any experience / comments welcomed.
> 
> 
> Mark
> 
> http://www.cobweb-dot-com.au/~dkfinnis
> 
> 

Mark, you have a *very* nice looking coil!  And the poly pipe will make a superb 
coil form for your next coil.  With poly, I would not be concerned with wall 
thickness at all - except for the weight.  BTW, how much does this piece 
weigh?

Bert Pool