Re: Tesla Coil RF Transmitter: Tesla DIDN'T use 10s of KHz

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: William Beaty <billb@xxxxxxxxxx>

On Thu, 6 Oct 2005, Tesla list wrote:

> "    A point of great importance would be first to know what is the
> capacity of the earth? and what charge does it contain if
> electrified?  Though we have no positive evidence of a charged body
> existing in space without other oppositely electrified bodies being
> near, there is a fair probability that the earth is such a body, for
> by whatever process it was separated from other bodies-and this is
> the accepted view of its origin-it must have retained a charge,

It cannot have retained a net charge, since the solar wind is a conductor.
If the Earth has a strong negative charge, then it attracts protons out of
the solar wind while repelling electrons.  In other words, the net charge
leaks away downstream.

The Earth probably does have a net charge, but this will be caused by the
solar wind: by net currents created by nonuniform magnetic fields in the
solar system.

> 	As noted above, the properties of this "condenser", as well as its
> charge, have become known since Tesla's time.  We can calculate the
> reactance of same at the lowest resonant frequency of about 7.8 Hz; it's
> about 0.08 ohms.  If Tesla's "alternating dynamo machine" were to charge
> this to a million volts, far lower than the values he discussed, the
> current flowing would thus be 12,500,000 amperes and the associated
> reactive power would be 12,500,000 MEGAWATTS.

That's the trapped energy in the Schumann cavity, not the driving energy.

In any tank circuit, the reactive power between inductor and capacitor is
far higher than the real power driving the tank circuit's losses.

> He didn't mention that, but in his patents refers to maintaining this
> voltage with "a few horsepower". It all goes downhill from there.

If the Q of a resonator is arbitrarily high, then the driving energy is
arbitrarily low.  If Tesla had some way of actually radiating a few
horsepower of VLF down around 100Hz or lower, then multiply it by cavity-Q
to find the wattage in the Schumann cavity.  The big question then is:
what is Q?

Here's a bit of new info.  At the Lightning lecture at the UW yesterday,
the VLF specialist from New Zealand pointed out that, at 10KHz where most
of the RF power radiated by lightning is located, the RF energy doesn't
make it around the Earth many times.  After just one pass around the
globe, the
broadband signal (w/10KHz peak) is mostly gone, but it's not decreased to
total insignificance and causes problems in their lightning-locator
algorithm.

You can see this directly.  This link leads to realtime spectra of
lightning from their worldwide VLF antenna project.  The pulses DON'T have
long ringing tails lasting for many seconds.  This shows the very low Q
present at KHz frequencies and above.

   VLF lightning spectrogram at Seattle, 0KHz to 24KHz
   http://togasea.ess.washington.edu/%7Esferix/vlf.png

   WWLLN  at the U. of Washington
   http://webflash.ess.washington.edu/

Keep in mind that Tesla mentions that Earth resonances fall to
indetectability above 20KHz, and frequencies anywhere near that range are
worthless for power transmission, since signals are strongly absorbed.

It would be interesting to see a plot of Shumann-resonance Q values versus
frequency for 1hz and up, plotted on a log scale.


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William J. Beaty                            SCIENCE HOBBYIST website
billb at amasci com                         http://amasci.com
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