Re: Halloween Coiling and the FCC

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

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
<twftesla-at-qwest-dot-net>" <meknar-at-hotmail-dot-com>
 
> 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
	elevation.

> 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
	radiate.

	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.
	Good point. 


> larry.
> ...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.

	Excellent point...


	Harmonics AND non harmonic strays from lead	

	resonances will probably show up.


-- 
	best
	dwp

...the net of a million lies...
	Vernor Vinge
There are Many Web Sites which Say Many Things.
	-me