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Re: Halloween Coiling and the FCC
Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>
Tesla list wrote:
> Original poster: "Laurence Davis by way of Terry Fritz
> I've walked around my neighborhood with a longwave
> radio that tunes to the frequency of my coil, which
> is around 220khz.
Might be instructive to try higher freqs, both
harmonics of the 220 KHz and 'strays' from the
resonances set up by leads on, eg spark gaps.
> The coil is in the basement.
Results, especially from VHF, may vary with higher
> While walking around I have about a 3 block radius of
> perceptable noise from the coil. Right now I'm using
> 12kv/60ma nsts. I was using 12kv/120ma until they died,
> but even then the transmission range was near the same.
> I have a partial faraday cage around the coil. Essentially
> a box without a bottom and a 3ft wide door in the front.
> Hardly a "cage" and most likely has little reduction in
> the transmission.
At the fundamental (220KHz), probably a fair cage,
as the freqs are low, wavelengths long.
I'd think that the 'door' edges, maybe the bottom
edges would resonate at their 1/4 wave freqs, and
AND. Any cage is limited by the filtering of the
power (and other) leads. A partial screen may
make a nice strike rail, and, as counterpoise,
reduce emissions. Fully screened is a lot tighter,
especially with VHF strays.
> Just thought I'd mention it anyway though.
> ...Oh, the radio is a radio shack dx398 shortwave radio
> which has a long wave on it. Perhaps I will try on a
> higher harmonic and see how it goes.
Harmonics AND non harmonic strays from lead
resonances will probably show up.
...the net of a million lies...
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