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RE: Longitudinal Wave Experiment



Original poster: "David Thomson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>

Hi Ed,

>> I'm talking about the ground plane, not the ground.  The ground plane for
a
>> quarter wave antenna is the surface between the earth and the atmosphere,
>> not the earth below the surface.  By definition, the ground plane is zero
>> volts wrt a resonant quarter wave antenna.

>	I am talking about the same ground plane. Not quite sure what you mean by
your definition, or that last sentenc, .but a grounded vertical antenna (or
one fed between the base and the ground) has an equivalent image in the
earth, fed with the opposite current polarity.  Input impedance and
reactance are exactly half those of an isolated half-wave dipole.  The
radiation from the vertical antenna is vertically polarized, and the maximum
field strength is at the ground level (or angle, if you prefer). Along the
same lines, a TC is equivalent to a very short vertical helical radiator
with capacitive top loading, and will excite the same currents in the
ground.

Exactly.  There is a mirror image of the antenna radiation pointing into the
ground but with opposite polarity.  The point where these two opposite
pointing radiations join is at the ground plane.  The ground plane is a flat
plane of zero volts that extends in all directions perpendicular to the
antenna and its resulting mirror image.  Below the ground plane of zero
volts is a field with opposite polarity to the field above the ground plane.
The space under the surface of the earth has voltage just as the space above
the surface of the earth (in the case of a quarter wave resonant antenna.)
That means that deep in the ground, the "ground" is not zero volts.

Longitudinal waves are strongest when the electricity is propagating at (or
near) zero volts, along the ground plane.  That is my point in entirety.

>	You are making a horizontally-polarized antenna and, in principle, is
should have zero output when it is oriented perpendicular to a line to the
transmitter, whether or not there is a ground present.

Great.  Then if I capture energy from this supposed zero output
configuration, then I will have proved something.  I am aware of the
beverage antenna.  I'm trying particularly _not_ to capture the RF component
of the wave, which would happen if I turned the antenna parallel to the line
of the transmitter.

>> I will also cut three metal pipes.  One will be 3 times the wavelength of
>> the half wave, one will be three times the length of the full wave, and
one
>> three times the length of pipe where the nodes are spaced equal to the
half
>> wave of 1390KHz.  If there is a longitudinal component to this wire
>> arrangement, it will cause these pipes to mechanically resonate.

>	You're talking about over 1000 feet of pipe.

707 feet actually, but you're point is correct!  I made a mistake with the
way I wrote down 1390KHz.  I ended up designing something for 1.39GHz.  I'll
have to redesign the experiment or think of something else.   The spacing
between the wires would have to be 354 feet to do the experiment I had in
mind.  Maybe I can replace the linear wires with flat spirals or solenoid
wound coils?  I'll think about this.

Dave