On 10/16/2020 6:40 PM, Larry B. via TowerTalk wrote:
I believed their PR copy that radials were not needed.
A point of clarification. There ARE a number of monoband and multiband
vertical dipoles with decent performance, and as a class of antenna,
vertical dipoles do NOT need radials. Most of them use some form of
loading and lots of matching tricks. Hy-Gain AV-series and Cushcraft
R-series are vertical dipoles. First rate antenna designer N6BT has
designed a lot of vertical dipoles, first for his Force 12 company, and
for his current company, Next Generation Antennas.
There are several tutorials on vertical antennas on my website.
http://k9yc.com/VerticalHeight.pdf
http://k9yc.com/AntennaPlanning.pdf
N0AX, since 2010 the editor of the ARRL Handbook and Antenna Book, and
K7LXC, master tower climber, performed setup and on-air measurement of a
dozen or so verticals and about that number of multiband Yagis, and
produced excellent reports. Their test methods were excellent, and so
were their written reports. They can be purchased online from K7LXC's
website, Champion Radio. I strongly recommend both.
I also strongly recommend N6BT's "Array of Light," which is a sort of
compendium of several years worth of his technical writing about
antennas, and includes details for several dozen of his Force 12
designs. It's particularly good on antenna theory, design concepts, and
at debunking deceptive advertising claims. Tom's book is now sold by ARRL.
73, Jim K9YC
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