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Re: coil form questions
From: Alfred A. Skrocki[SMTP:alfred.skrocki-at-cybernetworking-dot-com]
Sent: Sunday, November 16, 1997 3:02 AM
To: Tesla List
Subject: Re: coil form questions
On Sunday, November 16, 1997 2:34 AM randy-at-gte-dot-net
[SMTP:randy-at-gte-dot-net] wrote;
> I tried to post some of these questions previously, but either the
> post didn't make it or the replies never made it to me.
>
> 1.What about fiberglass? If properly sealed, would this make a suitable
> form material? They do make helical-wound 'glass antennas for HF use.
Fiberglass is atwo phase material comprised of glass and a binder,
sometimes epoxy is used but other binders are used as well. The glass
component is ok although not as good as polyethylene, the binder is going
to make or break it depending on it's internal leakage resistance and power
factor. I once used an epoxy-glass double sided printed circuit board
material to make a capacitor for a minature Tesla coil and it worked well.
> 2.What about tapered coil forms; any problems here?
Yes their a b*tch to wind! The windings tend to slip down the cone,
Tesla himself tried using a cone shaped secondary figuring it would allow
higher output before primary to secondary breakdown would occur, in the
long run he found it wasn't worth the trouble. Every once in a while others
revise the idea but it always seems to be short lived.
> 3.What about those orange "road cones" for traffic control. The usual
> variety that I see are one-piece semi-rigid or rather floppy, but I
> have seen 2-piece (base,cone) type that are somewhat stiffer.
I have seen some that are made colored polyethylene and except for possible
R.F. absorption by the coloring agent they should work fine except again it
is going to be difficult winding on a cone. As for the other materials
who knows, the deciding factor is going to be the materials internal
leakage resistance and it's power factor which determines how much R.F. it
absorbs.
Sincerely
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Alfred A. Skrocki
Alfred.Skrocki-at-CyberNetworking-dot-com
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