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Old September 8th 09, 07:02 PM posted to rec.radio.amateur.antenna
Richard Fry Richard Fry is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 440
Default The ultimate tilted monopole

On Sep 8, 12:30*pm, Art Unwin wrote:
So far you have shown
progress by tipping the radiator where it started to fill the void at
the center of the donut. This alone confirms the idea that another
vector has to be considered outside the arbitrary border


The change in the elevation pattern shape and gains seen in the
"tipped" NEC plot I posted are NOT due to equilibrium, vectors outside
boundaries, shear forces, torque, spin etc.

The change in the pattern of the tipped vertical dipole are due to
changes in the amount and direction of the energy radiated toward the
earth by, and near the antenna, and the net field that results by the
vector addition of that reflection with the energy radiated in a given
direction by the dipole itself.

Suggest you use NEC to model a vertical dipole in free space, at
several physical rotation angles away from plumb. See if the gain and
shape of the radiation pattern changes (they won't, if your model is
valid).

Also note that the Poynting vector does not take the form of a perfect
sphere for any linear antenna -- only for a (non-existent) isotropic
radiator.

RF