For the purposes of radio signals, does the shape need to be a specific
paraboloid? Certainly at optical wavelengths a parabola is needed to
focus light from infinity, so a parabola is needed. But at radio
Frequency wavelengths a true parabola is not likely needed. In fact,
considering the difference between a sphere and a parabols, I would
suspect that anything out there is not a true parabola unless it is
arrived at by chance.

- Mike KB3EIA -


No; but optimum aperture efficiency is attained with a point feed, as you get
with a true paraboloid. Spheres work too--if you can make a good line feed.

If you are willing to throw a few dB away, and don't care about the sidelobes
and shape of the main beam to any great degree, then all kinds of imperfections
from paraboloids work well.

Of course, a pringle can also works at 2.4...so there are many options.

73,
Chip N1IR