Caveat Lector wrote:
Here is a site for examples of capture areas of antennas

http://www.sommerantennas.com/gain.html

--
CL -- I doubt, therefore I might be !

As a 'rule of thumb' the captured signal power in small loops is
proportional to the area enclosed by the loop. Twice the area = twice
the
power (3 dB).


That's all nonsense, including the Sommer site!!

Capture area, more correctly called effective aperture, and gain has
nothing directly to do with physical area of an antenna. It is strictly
a function of the operating wavelength and gain of the antenna.

If I double the size of an antenna the capture area (effective
aperture) might increase, decrease, or stay the same.

If I have a small loop and it has zero loss, the capure area is
effectively very large.

If I have a full size dipole and add enough loss resistance, capture
area is very small.

Capture area is generally an excuse people make to justify using a
larger antenna, even if the antenna does not work as nearly as well.
"My quad works great for receiving because it has large capture area."
Nonsense. If it has the same gain as a Yagi on the same band, it has
exactly the same capture area. If it has less gain than a Yagi (which
many quads do, hence the reason you don't see them in contest stations)
it has less capture area.

I'd be ashamed if I was selling antennas and did not understand what
capture area was.

73 Tom