On Fri, 27 Apr 2001 "Tim Makins, EI8IC" <ei8ic@eircom.net> writes:
>
SNIP
> Try a full wave delta loop for 80m - much better than a vee in my
> opinion.
>
> Tim, EI8IC
>
I believe an inverted vee will outperform a HORIZONTALLY POLARIZED
DELTA LOOP (fed at the apex or in the center of the bottom wire) with
the same Apex Height since the EFFECTIVE Height of the Delta Loop
is much lower due to the bottom wire being so close to the ground.
A VERTICALLY POLARIZED Delta Loop IS a very effective DX antenna.
Feed 1/4 WL down from the Apex. Note that an equilateral loop for 80M
is over 80 ft tall and thus must be "squished" to fit on a 70 ft tower,
or,
have the bottom corners pulled out from the tower. The pattern of a
vertically polarized Delta Loop is more nearly omni-directional (3 db
F/S)
than an Inverted Vee. Feed impedance is 100+ ohms which can be
matched with an odd number of wavelengths of 75 Ohm coax. Loop
length should be made ~10 ft shorter than formula length due to
loading effects of the ground.
de Tom N4KG
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