Re: PC board primaries

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Good idea.. a spray on conformal coating...

Tuning is also potentially an issue, since it's hard to slide a tap, but
maybe if there are terminal points every 1/4 turn...


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, December 07, 2001 7:36 PM
Subject: Re: PC board primaries


> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
> Hi Jim,
>
> I have never hear of this being done but it sounds like a great idea for a
> modest sized coil.  The board and etching will probably cost a little more
> than some things, but not bad.  Heat "might" be a concern but I think it
> will work fine.  You may consider a HV coating to discourage surface
arcing
> between turns.
>
> Cheers,
>
> Terry
>
> At 01:43 PM 12/7/2001 -0800, you wrote:
> >Has anyone ever tried making a flat primary by etching a piece of copper
> >clad board?  With suitable copper thickness, the AC resistance might not
be
> >all that bad (skin effect, and all).  Say you etched  a 1/2" wide spiral
> >trace... 2 oz copper is 0.007112 cm  Skin depth at 300 kHz in copper is
> >around 0.01 cm..  Double sided board, with the spiral on both sides,
might
> >have a decent cross sectional area.
> >
>
>
>