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Re: Topband: One way propagation

To: "Tom Rauch" <w8ji@contesting.com>, <Topband@contesting.com>
Subject: Re: Topband: One way propagation
From: "EP Swynar" <gswynar@durham.net>
Date: Sun, 11 Nov 2007 08:16:39 -0500
List-post: <mailto:topband@contesting.com>
On 11th November, Tom wrote...

"...I have a few mirrors or refractive pieces of irregular
 shaped metal to make a multiple hop path between two points. I have a LASAR
to simulate the ray. Can someone tell me how to position the reflectors so
the
 light only goes between the same two points in one
 direction?"

*************************************


Excellent food for thought, Tom --- I never would have thought of it that
way before...

However, the more I contemplated your notion (on paper now, because this IS
really interesting to me), it suddenly dawned on me just how "...one way
propagation" might occur --- MAYBE. I throw this up for the group to reflect
upon (no pun intended!).

Consider this, going back to the "experiment" with the mirrors: the set-up
pre-supposes that the lasers at each end of the "path" are aimed at the same
angle to the mirrors above & below...correct? That being the case, the ray
of light would, indeed, reflect with the same intensity BOTH ways...

Now, leave the one laser at the same "ideal" angle (for maximum reflective
power at the receiving end), but this time, change the angle of the second
laser --- either that, or replace the sharp laser beam with something that
might shoot a broader beam width (or both)...

Do you see where I'm going with this...? I think I may well have answered my
own question...

In my real-world example, where the European is coming through at a "599",
the take-off angle of his antenna is ideal for the ionospheric conditions
such as they might be at that moment --- that's why I hear him so very well.
Now, had *I* the very same power AND radiating characteristics of his
aerial --- i.e. the same gain, same beamwidth, same take-off angle --- then
I, too, would be equally as strong at HIS end...correct?

But my antenna is not as "sharp" as the European's, & it has a higher
take-off angle...result: my signal is not as "focused" as the European's
signal is.

Conclusion: what I take to be "...one way propagation" is, in truth, a
mis-match of the radiation qualities of my antenna vis-a-vis that of the
station I am trying to work. There is no such thing as one-way
propagation --- just different antennas & power...

Does any of this make sense...?

~73~ Eddy VE3CUI - VE3XZ

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