On 2012-12-25 7:40 PM, Jim in Waco WB5OXQ wrote:
I meant a full wave loop
If I can support a wire antenna at 50' or maybe more in tall pine trees and
have 1.9 acres of space to use which would work best.
Lots of tall pine trees on the lot. I assume the trees in the center of the
square will really not be an interfearing factor. If I feed with window
line will it work well for a multiband antenna? I assume the inverted l
will need long radials to work well and that is possable, does the square
antenna also need radials and if so how oriented? Prospected area of
installatiion south Florida.
A horizontally polarized antenna, such as a 1 wavelength circumference
loop, at 50 feet high, is good for NVIS, since it's just under 0.1
wavelength above ground on 160m. From anecdotal reports, it might
provide some benefit for DX at sunrise/sunset under certain conditions,
but an inverted-L will normally be a better workhorse. Adding ground
systems under horizontally polarized antennas could slightly improve
high angle signals, but probably aren't worth the effort in most cases.
An inverted-L definitely needs radials, either on-ground or elevated.
There have been many discussions on the Topband list about these. Check
out N6LF's articles for well documented experimental insights on ground
systems, especially the data for antennas with vertical heights less
than 1/4 wl, which would include inverted-Ls.
Pine trees taller than 100 feet could be an issue, since they could be
near resonance and lossy - a sad combination when within a wavelength or
so of vertically polarized antennas. If your trees are 50 footers, they
would probably not be of concern on 160m, but could be on 80m. For
horizontally polarized antennas, the trees aren't a problem.
73, Terry N6RY
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