RE: Longitudinal Wave Experiment

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

Original poster: "Jan Florian Wagner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jwagner-at-cc.hut.fi>


> 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.

And that's exactly what it is - a mirror image, created on the surface of
the ground plane (attracted charges, and current loops). 

There's NO field below inside the ground plane.

The bipolar Tesla coil, with the center grounded (no ground plane BETWEEN 
the coils!!), is equivalent to a classic 1/4wave TC that is standing ON a
ground plane.

But by introducing a ground plane BETWEEN the two coils of the bipolar TC,
you end up with two separate 1/4wave coils that both see their mirror
image on the ground plane. 

This means that these coils don't have to reside vertically on the same
line (as is wrongly shown on your web page). 
They could be moved many metres wide apart, without any change in
operation. 

cheers,
 - Jan

--
*************************************************
 high voltage at http://www.hut.fi/~jwagner/tesla