On 11/27/2010 09:08 PM, Rick Karlquist wrote:
> VK1OD did a nice analysis. Unfortunately, many hams are simply
> in a mode of "don't bother me with facts". They desperately want to
> believe in the paradigm of a tuner in the shack and a simple all band
> antenna at the other end of the line, such as a plain vertical conductor,
> or a random wire, or a "loop skywire", a "G5RV," or some sort of "Windom"
> antenna. All continue to live on in ham folklore.
The big horizontal loop antenna seems decent, provided it is
cut at a length that gives it a good match on not just the
primary band but also the others:
http://surriel.com/radio/multi-band-hf-loop-antenna
One big factor that cannot be overlooked is the antenna
height. If the antenna is low, performance will suck, if
the antenna is high it will have a low takeoff angle and
do fairly well.
It is also an easy match to the radio, with an SWR below
2:1 for pretty much all of 80 and 40 through 10.
As for windom / g5rv / random verticals ... they all have
takeoff angle and/or matching issues that make them essentially
single band antennas - some of them not good at any band :)
I realize that a properly installed beam antenna will outperform
a wire antenna any day. However, given how poorly some people
install their beam antennas (30' tower, lossy coax, not exactly
sure where it's pointed, etc), I would not be surprised if a
properly planned and installed wire antenna outperformed a fair
number of the poorly installed beams out there.
My point? Even a good antenna can be a poor performer if the
entire antenna system is not carefully planned. Conversely,
a simple wire antenna can be a decent performer if the system
around it has been carefully planned (low SWR loss, good takeoff
angles, etc).
What matters is the antenna system.
--
All rights reversed.
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