Re: Secondary coil form questions

To: tesla-at-pupman-dot-com
Subject: Re: Secondary coil form questions
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
Date: Tue, 11 Feb 1997 12:38:47 -0800
Subscriber: bert.hickman-at-aquila-dot-com Tue Feb 11 23:18:03 1997

Tesla List wrote:
> 
> Subscriber: ccrochet-at-premier-dot-net Mon Feb 10 21:37:34 1997
> Date: Sat, 8 Feb 1997 09:29:15 -0600
> From: Chris Crochet <ccrochet-at-premier-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: Secondary coil form questions
> 
> At 11:25 PM 2/7/97 -0700, you wrote:
> >Chris,
> >
> >One of the highest Q coils I ever wound was on 4" diameter styrene with a
> >.030 wall thickness.  I never coat my coils with anything any more.
> >
> >Yes, make them thin walled tubes from the lossest loss material possible.
> >Avoid coating, if possible.  This assures highest Q!...  If that is what you
> >are after!
> >
> >Richard Hull, TCBOR
> 
> Thanks!  I will consider the use of styrene in my 1st design.
> 
> Is there anywhere a database or program which would show the theoretical 'Q'
> of the same secondary wrapped on many different types of plastic coil forms?
> 
> Chris C.

Chris,

Not that I'm aware of. However, as long as you pre-treat the PVC by
drying it and coating the inside and outside with polyurethane, your
coil's performance will be excellent. ABS, polystyrene, HDPE,
Polycarbonate (Lexan), Polypropylene, PMMA (Plexiglas), or glass-epoxy
coilforms can be used as-is with no pretreatment required. Stay away
from cardboard - it won't withstand the voltage levels. 

Q is governed more by the wire size, form-factor (height versus
diameter), and operating frequency than by the material used for the
coilform itself. 

-- Bert H --