On 10/20/20 1:21 PM, jimlux wrote:
On 10/20/20 1:01 PM, David Gilbert wrote:
Electrically, a half wave vertical dipole is not a lot different than
a quarter wave vertical fed against radials or a counterpoise, but it
requires a LOT more height to put it up. I just modeled two different
antennas in EZNEC+ as a comparison (both over medium ground):
A lot of these antennas are an electrically short dipole. so they don't
require the height. From a gain standpoint, an infinitesimally small
dipole is 1.5 dBi and a full size dipole is 2.5 dBi (mostly from the
broader lobe for the short antenna).
What might be interesting is modeling, say, a 25 foot dipole with the
center 13-14 feet off the ground.
Of course, one advantage of a full size vertical dipole is that the
"center of radiation" is 1/4 wavelength from the ground. on 80m that
puts it 65+ feet off the ground, and a horizontal dipole at that height
would also perform fairly well, no?
I think that's going to be the dominant effect.
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