[Elecraft] Need help from an EZNec user on a horizontal loop question
Jim Brown
jim at audiosystemsgroup.com
Sun Jan 1 21:58:13 EST 2017
On Sun,1/1/2017 6:44 PM, Don Wilhelm wrote:
> It takes up little real estate for the radiator, but does require
> putting down a ground screen at the base of the inverted L.
To avoid confusion about how antennas work, it's best to call this a
counterpoise, and leave the word "ground" out of it. The first function
of a counterpoise is to provide a path for return current. The earth is
a terrible path, because it's basically a big resistor, so it burns a
lot of transmitter power, leaving less for the antenna to radiate.
Radials are a nearly ideal form of counterpoise, because they not only
provide a low resistance source for return current, but they also shield
the antenna from lossy earth.
In addition to the very good solution that Don described, there are
other possibilities. K2AV has designed what he calls a "folded"
counterpoise that fits on a pretty small lot. Google to find details.
His original design was for 160m, but it can be scaled for 80M.
I've given several talks to ham clubs about "getting on 160 from a small
lot." It's mostly about antennas and counterpoise systems.
http://k9yc.com/160MPacificon.pdf For 80M, divide the dimensions by 2.
73, Jim K9YC
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