----- Original Message -----
From: "ZR" <zr@jeremy.mv.com>
This is where I think the problem is. You say:
** Since the TOA is established at almost ground zero, radials can
increase the energy at angles that would
otherwise be attenuated.
That is incorrect.
Radials, unless they radiate through some flaw such as a single radial
system that allows far field radiation, do not meaningfully affect TOA. This
is all over the place in all sorts of books, and a knowlege of reflections
and angles would tell us the idea radials close to the antenna affect TOA
makes no sense with any vertical, unless the feedline or radials are acting
like antennas in the far field.
The elevation pattern is established some distance out from the antenna.
Radials almost exclusively (if reasonably balanced or in large enough
numbers to have minimal currents) alter efficiency, nothing else.
It is the explanation that confuses many since the facts about radials is
real. A few
on here seem to be unable to seperate the feedpoint measurements and
calculations from radiated losses at
the lowest angles. An improved ground away from the base doesnt even have
to be connected to it to be effective.
The elevation pattern is formed by the distribution of current in the
vertical element and the ground out several wavelengths. The lower the
angle, and more elevated the high current area, the further out the area
responsible for pattern formation moves.
If you don't trust multiple people on this reflector, you might read 20-17
in the Antenna Engineering Handbook by Jasik, and dozens of other
engineering sources listed in the references at the end of that chapter.
Quoting Jasik, "ground system losses dissipate a portion of the input power
and reduce the field radiated from the antenna. These losses are equivalent
to the power dissipated in a resistor is series with the antenna impedance"
There are many good references out there. Even the ARRL Handbooks have
addressed this issue.
_______________________________________________
It is undesirable to believe a proposition when there is no ground whatsoever
for supposing it is true. - Bertrand Russell
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