TopBand: Dip/Vert Test Results

[W2pm@aol.com]

I think comparing antennas performance can be extremely misleading since
there are SO many variables at either end - thats why antenna test ranges are
so complex.

One of the obvious pitfalls of comparing a horizontal antenna vs a vertical
involves the all important ground system on the vertical.  This of course is
not so important on a horizontal so a possible scenario could easily be a
dipole or V - the V should always be somewhat less than a flat dipole -  with
a takeoff angle of < 40 degress showing more signal at the receive end than a
nice Inv L with a taleoff of < 25 degrees.  The results COULD be due to the
height of the ionosphere etc but over a few thousand miles or so its more
likely that the losses on the Inv L would account for the difference unless,
of course, you are installed properly for a vertical - in the clear for
hundreds of wavelengths from the antennas with a good ground system.  No
matter how good a single raised radial can be its still no match in
efficiency vs a horizontal antenna installed in modest conditions.

The real point is not to draw conclusions or even and single data elements
from tests which are not carefully controlled.  Kinda like seeing if 2, 500
mg aspirins work as good on a 250 pound man (typical ham) as 2 Tylenol's work
on 120 pound lady.

73 Pete

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