On Mon, 24 Dec 2007 10:06:07 -0800 (PST), Rick Karlquist wrote:
>This illustrates the importance of having a variety of receive
>antennas. You never know which one is going to be optimum.
Yes. I regularly work LP from the Bay Area to EU in the morning on
40M. Signals are ALWAYS stronger on my high dipole than on my
Beverages. On 160, it's often a toss-up as to whether the vertical,
the dipole (up 30M), or a Beverage will be better for any given
signal.
AND -- don't forget about fading and diversity. Most fading is
cancellation between wavefronts that take different paths, and are
thus out of time (and thus out of phase to varying degrees) with
each other. Cancellation is most severe when the levels of the two
signals are precisely equal and precisely 180 out of phase. Antennas
at different locations, heights, and directivities will cause both
time and amplitude of those multiple arrivals to vary with respect
to each other. Never underestimate the value of diversity reception!
73,
Jim Brown K9YC
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