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Re: Secondary coil form questions

Tesla List wrote:
> 
> > > Subject: Re: Secondary coil form questions
> > Subject: Re: Secondary coil form questions
> > > Subject: Re: Secondary coil form questions
> 
> Subscriber: major-at-vicksburg-dot-com Wed Feb 12 23:04:20 1997
> Date: Wed, 12 Feb 1997 20:51:17 -0800
> From: roderick maxwell <major-at-vicksburg-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Secondary coil form questions
> 
> Tesla List wrote:
> >
> > > Subject: Re: Secondary coil form questions
> >
> > Subscriber: bert.hickman-at-aquila-dot-com Tue Feb 11 23:18:03 1997
> > Date: Tue, 11 Feb 1997 12:38:47 -0800
> > From: Bert Hickman <bert.hickman-at-aquila-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Re: Secondary coil form questions
> >
> > 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 --
> 
>   Does anyone know of any companies that sell polystyrene tubing larger
> than four inches in diameter? My first coil has a styrene secondary and
> I really like its performance.For my next project I'm going to build a
> smaller coil that will resonate at about 1Mhz. But in the future when I
> get more space to build and operate my coils I would like To build A
> MONSTER! I like the fact that styrene has such low losses in the RF
> range, it is hard, rigid, tough, and coatings stick to it well. The the
> only problem is I can't find any in a large enough diameter. If anyone
> knows of such a company the information will be greatly appreciated!
> 
> 
> 
>                                 Frankensteins Helper
>                                        Max

Max

I build my secondaries using acrylic rod and plates to make up a
skeleton
frame. I previously built a polystyrene secondary and I believe the Q's
for acrylic skeletons and polystyrene are similar. Large diameter
polystyrene is extremely expensive.

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