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>

It would be a big inductor by printed wiring standards, and it's a terrible
radiator at RF frequencies where interference/spurious emissions are a
problem(being physically small, and coupled to a lossy secondary/arc system
to boot).

The feds show up in a white van with US Government plates, and the words
"Federal Communications Commission" painted on the door. It has antennas
sticking out of the top, and they wear ordinary shirts and trousers
(Dockers, e.g.), and no coat and tie. No men in black, as it were...  Been
there, seen it, etc...

For what it's worth, I had two friends try to direction find the SoCal 2000
Teslathon by looking for RF emissions. (They left the directions at home,
knew it was in Acton, and figured that they were experienced T-hunters, etc.
They were driving aimlessly on the wrong side of the freeway, and never did
find it.  That would probably have been the biggest concentration of amateur
RF noise generators around.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, December 08, 2001 10:22 AM
Subject: Re: PC board primaries


> Original poster: "R Heidlebaugh by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>
>
> on 12/07/01 8:36 PM, Tesla list at tesla-at-pupman-dot-com wrote:
>
> > 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.
> >>
> >
> >
> Printed-board flat primary coils are used, but in a TC you are working
with
> low frequency not 400 MHz+ and you dont want your equipment able to
generate
> unlimited high frequency TVI for FCC to find a reason to send the
black-suit
> boys to visit you.
>    Robert  H
>
>
>