On Mon,9/7/2015 1:05 PM, K1FZ-Bruce wrote:
Thanks Jim, There are new hams that do not know how horizontal
antennas patterns change over ground.
Right. In general, horizontally polarized antennas only care about
height, while vertically polarized antennas care SOME about height, but
mostly about soil conductivity. I gave a talk at Pacificon and to a
couple of ham clubs on this based on an extensive NEC modeling study.
Slides are here.
http://k9yc.com/VertOrHorizontal-Slides.pdf
On 160 meters, Usually, but nor always, higher is better up to 1/2
wavelength for low angle DX..
Lousy soil, like low conductivity sand, dry desert soil, can put the
effective conducting ground much lower than the surface soil
DX does not always come in at low angles. Antenna handbooks ARRL, and
Low Band DXing books are worth reading.
N6BV's Antenna Book statistical data for use with HFTA are an excellent
resource in that regard, but I think the data for 160M is interpolated
from data for higher frequencies. And yes, the ON4UN book is excellent
on that topic.
73, Jim K9YC
73
Bruce-K1FZ
www.qsl.net/k1fz/beverage_antenna.html
I saw that statement as well, which noted a gain of -53 dBi. My NEC
model, using Carlos's dimensions over lousy soil, computes -44 dBi with
a peak at 24 degrees.
73, Jim K9YC
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