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Re: Wireless Transmission

Original poster: "Mike" <induction@xxxxxxxxxxx>

Hi Ed,
            I was providing the links for Drew as he was
looking for information about all sides of the issues. Know
about verticals, have built AM broadcast stations raw swamp
through final proof with an FM on tower one.OK on Tesla's
using a discharge tube as half the circuit, I've pulled 860 amps
through the one here at many pressures, 22.5 inch ID, no
problem, could have taken several thousand.
Also OK on the Tesla transmitter, seen the losses when tuning
a 75 meter mobile, worse a 160 meter mobile antenna.
Not an issue for his plans, my mobile antenna was very narrow band
so I stayed near where I hung out with the other AM'ers, 3.885
on 75 meters. It's nice that you collected the Zenneck book.

----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Friday, January 14, 2005 7:31 PM
Subject: Re: Wireless Transmission

Original poster: Ed Phillips <evp@xxxxxxxxxxx>
"Here are some links regarding Zenneck Waves, Scalar Waves. What I
believe about them is not important, that you give the concepts fair
deciding one way or the other, or decision pending, is important. Move
The so-called "Zenneck waves" are the common "ground waves" through
which most AM broadcast stations reach their listeners.  A base-fed
vertical antenna sitting on a ground plane will radiate with the maximum
value of the vertical E field directed along the ground.  If the ground
is an imperfect conductor (which is always the case, even for sea
water), the wave will be bent "forward" along the earth's surface.
Zenneck's classic "WIRELESS TELEGRAPHY" (my copy is the English
translation) has a good explanation and also points out that the
attenuation of such waves is such that they are very much weaker at a
long distance than the radiated wave would be if the earth were a
perfect conductor.  He gives values for losses as a function of
frequency and ground conductivity.  Since, for the simple
non-directional vertical antenna, the energy propagates equally in all
directions, the power density varies inversely as the square of the
distance, just as in free-space waves.  There's no free lunch here -
propagation of such waves is very lossy and of no use at all for power
Note that Tesla's transmitters, as described in considerable detail in
his patents, are just what we call today "base-loaded vertical
antennas", although of quite an inefficient design (vertical radiator
too short compared to a wavelength).  They do indeed radiate energy and
there are no magical low-loss "scalar waves" involved at all.  I read a
lot of words about "scalar waves" but I've yet to see a description of
how one would create or detect them.  Tesla's apparatus was very simple
and if he told the whole truth in his patents (in other words, wasn't
lying) his expected mode of propagation was to use the system earth (one
side) and the "conducting layer" he created in the upper atmosphere.
This would comprise a spherical transmission line, with all the losses
associated with finite conductivity of the earth and much smaller finite
conductivity of the ionized layer.  All kinds of problems with this
system and it's no wonder no one has ever built one.  His "proof of
design" experiment was to use a partially-evacuated tube to conduct
current from one location to another and there is no doubt that worked,
although with losses he apparently never measured. That gave him a
point-to-point transmission path so he had only ohmic losses for the one
path, not losses due to the dispersion of the current over a wide area.