On Mon,2/2/2015 10:05 AM, Don wrote:
First, I'm surprised there does not seem to be any published
measurements taken at a common test site of a Beverage at various
heights and lengths (such as done with yagi's, and other antennas on
test ranges).
Why do you assume that nothing like this exists? Beverages have been
around for nearly a century, and it is quite likely that there's a lot
of published work that you haven't looked for in scientific journals.
It's also possible to model antennas like this and do your own study.
There's a lot about Beverages (and other RX antennas) in the ON4UN book,
and in the ARRL Antenna Book.
Email reflectors like this one should not be a substitute for pulling
out the books and studying them. Many of us who post answers to
questions like this have done that study, or done that modeling, or
built those antennas, and are sharing what we've learned. As VE7RF has
noted, optimum height is a function of wavelength. When a Beverage is
higher than that, it doesn't stop working, like throwing a switch, it
just becomes less effective. My 550 ft Beverages, a full wavelength on
160M, at an average height of 5-6 ft, are quite effective on 40M, and
are still working on 20M! How do I know? I run diversity with my K3
using the TX dipole at 125 ft into the main RX and the Beverage into the
second RX.
73, Jim K9YC
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