It is great to see the technical discussion regarding topband antennas,
particularly the FCP. Thanks to K2AV for putting his ideas and design out
there for peer review. Hopefully the review process won't discourage folks
like myself, who are not antenna enginers, from trying various ideas, including
the FCP in limited space.
I agree antennas do not work due to magic. As N6BT said, everything works.
Some things work better than others. Measurng how much better one thing works
than another, on an engineering basis, is the difficult part. Most of us have
to resort to the Gotham method. Who can we work? How difficult is it to work
stations with the current antenna compared to previous antennas? How do our
contest scores compare with previous efforts? Without A/B testing, these
evaluations are subjective but over time, an experienced op gets a feel for a
relative level of performance.
Those of us who have learned antenna modeling have a way to do technical
comparisons of antennas up to a point but there are limitations. For example, I
have never been able to duplicate real world effects in the models of my tree
supported inverted L elevated radials. My models don't show the significant
effect of close proximity to ground on the radial resonant length.
Consequently, I just build the antennas, adjust the radials to the real world
length, and don't worry about what the model says. In my case, it is simply
not feasible to have an elaborate ground system, for various reasons.
My point is to encourage folks to study theory and try to understand the
technical aspects of antennas but, absent ideal installation conditions, to
put something in the air and try it. If you have limited radial space, try the
K2AV FCP. It is not complex or difficult to build. I don't know if it will
work as well as two resonant elevated radials and doubt if the model will tell
me, due to close proximity to the earth. However, I do believe the FCP does
achieve a level of perfomance better than what users have achieved with prior
limited space antennas. Again, these are experienced ops, not a bunch of
novices who get a leg tingle over working EU.
I intend to try a FCP and do A vs B testing on my site. Likely this will wait
until the rattlers and copperheads slow down in the fall. My goal is to see if
equivalent performance can be achieved between the FCP and a few elevated
radials, to save the real estate for rx antennas.
Antenna experts would laugh at my simple antennas and minimal radial systems.
However, they have been good for 216 countries and 37 zones since October 2008
on 160. Several of my WVDXA friends have confirmed 160 DXCC with a single
elevated radial. One just has to try stuff, and do the best one can with the
available resources.
Build something and get on 160! In 50 years of operating, I have had more fun
on 160 than any other activity, period.
73 Charlie N8RR
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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