In a message dated 97-01-22 12:16:13 EST, you write:
>
>Yuri's comments are very astute... I have tried discussing this with some of
>the locals, and nearly got lynched in the process.... The minute I took the
>position that propagation does _not_ involve 1 to 10 reflections between the
>surface of the earth and the ionosphere, smiling faces became frowns... You
>would have thought I had trashed their religion... they were waving articles
>on Minimuf, etc., at me... when I inquired, that if dirt is such a good
>reflector that it positively bounces microvolt signals back into the
>ionosphere, then why do they need dozens of radials under their verticals,
>they began to foam at the mouth, and I dropped the subject... Now I know how
>Galileo felt when facing the Cardinals in the church...
If I was there I would have foamed also.
Power loss is largely affected by current density, losses are I *squared* R.
When charge movement is spread out over a large area, losses are greatly
reduced in any media.
Spread a given amount of charge movement (current) over twice the area, and
power losses are reduced four times. You can bet the ionosphere's
accelerating charges (moving in light speed delayed step with charges in your
antenna) illuminate a very large area of earth, current density and losses
are much lower than when concentrated near an antenna. Simply put, the earth
looks like a much better reflector for a large wavefront than a concentarted
field.
So the radial argument doesn't work at all. Dirt is a MUCH better reflector
when charge movement is spread out over a very large area, as it is when the
distant ionosphere illuminates a wide area of earth.
By the way, tonight VK0IR had the first readable signal in Atlanta when the
SE path opened. The NE path has only produced weak unreadable signals with
much flutter. Tonight the NE signal was the same weak watery signal, but the
SE signal was slow QSB and peaked later with a readable 349 signal.
I've seen the same thing with 4S7, VS1, and VS6 from Ohio. VS6DO was
sometimes louder with less QSB southwest, some mornings west, and some
northwest. Many mornings he was readable with different QSB rates and peak
times in both directions.
The VK0 appears to be doing the same thing.
I'd hate to predict what is going on in the ionosphere by observation of a
few things on my receiver, plus it's not in my area of experience or direct
knowledge. Rather than hatch my own or dispute another's pet theory, I'll
leave that to *real experts* in that area.
Bob NM7M (or whatever his call is) seems to be one. I would also expect
people involved in minimuf to have done real research.
I am positive claims of ground loss precludes or restricts "multi-hop"
propagation are absolutely untrue. I am also absolutely sure VK0IR's signal
was propaging over two very distinct paths today, NE and SE, just as other
signals have done in the past from near opposite ends of the world.
73 Tom
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