Steve,
The half-square essentially consists of 2 quarter wavelength vertical
elements connected by a 1/2 wl phasing line. The feedpoint is at one or
the other junction of the phase line with a vertical element.
The full performance of the half sqaure is dependent upon maintaining as
close to 1/2 wl spacing/phase line as possible. One of the reasons that
the half square tends to show more gain and a more "peanut-like" and less
oval pattern than some like an equilateral delta is that the vertical
elements are much closer to optimally spaced.
Hence, altering the shape of the phase line may reduce gain faster than
bending the low-current loose ends of the vertical elements. Also, using
other than a straight line for the phase line will reduce the nearly full
cancellation of radiation from the line, thus producing a high-angle
horizontally polarized component to the pattern--actually enlarging that
component from its remnant size.
A little reshaping is not likely to hurt enough to tell, but significant
reshaping of the phase line may reduce the ability of the antenna to be
insensitive to close in QRM/QRN as the high angle component to the pattern
increases.
Where the point is that divides "a little that won't hurt" and "enough to
degrade performance" is not possible to specify for all installation
situations, with their limitations of height and length and surrounding
objects.
Hope these notes are useful.
-73-
LB, W4RNL
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