And your point is ??
That is not the only place where substitute arithmetic will produce a
different figure. You can do the same with ground losses in the immediate
vicinity, where if you do anything except the Norton-Sommerfield
estimations you come up with a different figure. NOBODY has possession of
the perfect computation. From where a lot of us sit, THE WHOLE THING is an
approximation of sorts. Only what happens out there is natural law. What
we are doing is trying to invent formulas that match what is observed.
Are we actually under the impression that someone has put down the absolute
equations? To allow that in our thinking is perilously close to
scientific arrogance. Until someone comes up with the undisputable system
of everything that explains gravity, all those piles of contradictions in
stellar observations, and the huge mass of not-properly-explained
observations and simply lays out how radio works, we need to have the
humility that our formulas are the best of our approximations TODAY.
Tomorrow may be an entirely different bucket.
Dark matter, dark energy...we're having a VERY hard time making our
equations stretch around the universe. Radio propagation, what goes on in
space between two distanced physical occurrences is part of that "stuff"
out there they can't get under control.
73, Guy.
On Sun, May 6, 2012 at 11:10 AM, Richard Fry <rfry@adams.net> wrote:
> Guy Olinger wrote:
> >It IS TECHNICALLY TRUE what you say, no argument, but of little use since
> >you don't get to keep it, UNLESS you can get it over salt water, or off a
> >mountain top. ... I can only spend take-home pay, and I can only make
> QSO's
> >with the take-home pattern. I don't see anything wrong with using the
> >take-home takeoff angle as the item of conversation -- it's the one you
> get
> >to use.
>
> Note in the link below that the value of the surface wave at 1 km at an
> elevation
> of 50 meters is about 110 uV/m, which is not much less than the 113 uV/m
> field
> shown by the NEC far-field analysis at the peak of the space wave at 1 km.
>
> Also note that the surface wave field at 1 km in the horizontal plane
> exceeds the peak field of the space wave at 1 km in the NEC far-field
> analysis for the alleged "takeoff angle" of this radiator, per my opening
> post in this thread. These NEC analyses are based on 5 mS/m real earth,
> not
> a perfect ground plane.
>
> A point elevated 50 meters above a plane surface from another point 1 km
> away on that plane surface has an elevation angle of 2.86 degrees. And
> while
> the calculated space wave is not much above zero field at that elevation
> and
> distance, the surface wave has a much higher value there.
>
> Unless that propagation path is obstructed by some physical object, nothing
> prevents such low-angle waves from traveling on to the ionosphere, which
> under the right conditions will result in their reflections returning to
> the
> earth as skywave.
>
> Monopole radiation at such low angles is part of its take-home pattern that
> also can make DX QSOs.
>
>
> http://i62.photobucket.com/albums/h85/rfry-100/Space_Surface_Wave_Compare.gif
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|
