The recent thread on 4 sq. vs Yagi on 80m got me thinking about my own
experience and the importance of surrounding ground conditions.
(I cannot compare my 80m 2 el Yagi with a 4 sq., since I don't have
both, but my Yagi plays very well.)
A vertical, or 4 -sq. located in a rural setting, especially surrounded
by flat farmland will probably perform like the models suggest.
However......
In an urban setting (city), the surrounding ground clutter could make
vertical performance questionable. As far as the eye can see, the VE6WZ
QTH is surrounded by pavement, sidewalks, houses full of electrical
wiring, covered in stucco with underlying wire mesh, metal gutters and
flashing, power-lines etc. etc. I'm sure this is similar to many other
"average" ham QTH's. What is the "actual" performance in these
situations regarding vertical far field pattern development? Is it
really as the models show? I suspect a combination of scattering and
absorption from all this clutter will greatly degrade actual
performance.
Likely the radiator of choice at many city locations is a vertical
because of space, and visual considerations (a small footprint, even
including a compromise radial system). However, **if** a tower is
available, I suspect a wire dipole or Vee, or better still a short
rotatable dipole, even at 50' on 80m could beat the "compromise" city
vertical. This has been my experience at VE6WZ. (except on 160). Even
at a "low" height, a dipole still has some decent low angle energy, even
though the peak angle is almost 90 deg. The horizontal radiator is less
dependant on the surrounding ground quality.
I do NOT challenge the fact that "model" verticals are better low-angle
radiators than low dipoles, and I don't doubt many have great success
with them in the city.....but.....if you are in the city and have a
tower and enough room, don't dismiss a wire or shortened dipole for 40
or 80m. Home brewing an inductor loaded dipole is not that difficult.
73, de steve VE6WZ. http://www.qsl.net/ve6wz/index.html
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