At 07:53 AM 2005-03-03, Earl W Cunningham wrote:
>A full wave loop (which I prefer to call a "quad loop"), will radiate
>straight up if it is mounted in a horizontal plane, even if it is 500
>feet above ground!! It might be useful for short skip (straight up,
>straight down) propagation, but any low-angle signal for DX use would be
>virtually non-existent.
At 02:57 AM 2005-03-03, Tom Rauch wrote:
>The loop tends to NULL the signal along the
>horizon, but the earth itself already nulls the horizontally
>polarized wave along the horizon.
Not to defend the horizontal loop as a great antenna, but there isn't much
of a tendency to null on the horizon compared to a dipole at the same
height. Mounted at 1 wavelength high, the signal at a 14 degree takeoff
angle is only down about 2 dB from a dipole along the line perpendicular to
the feedpoint while it's actually about 2 dB higher in the minima off the
"sides" compared to the signal off the end of a dipole.
The signal straight up is only about 2 dB higher, too. Yep, it's darn
close to a "feel good" dipole.
When I lived in the frozen north, near Seattle, one value of the loop was
apparent: you can connect it to a high current DC power supply and melt
off the ice buildup that threatened my 26 gauge stealth loop! It was later
replaced by a G5RV and nobody knew but me, my antenna tuner, and the ice.
Keep clam,
Terry
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