Yuri Blanarovich wrote:

What I had in mind is the difference in "capture area" related to physical
size of antenna like rhombic vs. similar gain, say Yagi. It appears that
rhombics perform better than corresponding Yagi thanks to larger physical
size (5 - 10 wave lengths) interacting with the environment (more like
diversity effect?).

That's a commonly believed myth, but myth it is.

It seems that rhombics perform better than calculated
gain/capture area figures.

So do EH, CFA, Isotron, Rai-beam, and more other antennas that I can
count. That's because modeling programs just don't account for the
magical effects.

We will have opportunity to do some tests of rhombics farm vs. some classics
soon. It will be interesting to see the results.

Maybe. Even fairly simple RF measurements are very difficult to make
with even modest accuracy. Antenna measurements are more difficult yet.

Roy Lewallen, W7EL