Re: PVC secondaries

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Dale Nassar by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dnassar-at-i-55-dot-com>

Greg,
PVC is such a popular coil form because it is cheap and easy to 
find.  Otherwise it is not a good Tesla secondary due the the high RF 
losses of PVC at these frequencies--also it holds water.  So by coating it 
with polyurethane you get a water tight low Rf form.  Yes, you should coat 
the form with an OIL-BASED poly.  Be sure you make sure the PVC is clean 
and dry first. Then wind the coil.  A poly or acrylic (plexiglass) 
secondary would be better but they are VERY expensive and harder to 
get/find.  I like to use thin-walled PVC, dried and coated before AND after 
winding--you want the coil embedded in the low-loss polyurethane.  I live 
in a hot climate and leave the pipe in the hot sun all day before coating.
--dale nassar


At 08:26 AM 6/28/02 -0600, you wrote:
>Original poster: "Mr Gregory Peters by way of Terry Fritz 
><twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
>
>Hello all,
>
>Some coil plans I have say that when using PVC as a coil form, it should
>be coated with polyurethane (or similar) BEFORE winding the wire on to
>reduce losses. Is this really necessary? I would have thought it just
>adds more loss by making the form wall thicker.
>
>
>Cheers,
>
>Greg Peters
>Department of Earth Sciences,
>University of Queensland, Australia
>Phone: 0402 841 677
>http://www.geocities-dot-com/gregjpeters