Yuri Blanarovich wrote:
. . .
Spacing two antennas few wavelengths can give us diversity effect by the
virtue of propagation and waves hitting them differently. Rhombic is kind of
antenna/feeders spread out over few wavelengths over ground. Perhaps there
is also some of traveling wave mode going on, like in a Beverage. You can't
simulate that . . .

NEC-based modeling programs don't have any problem simulating a Beverage
and its traveling wave operation -- they do quite well at it.
MININEC-based programs, no longer in wide use, weren't able to because
of the use of perfect ground during impedance and current calculations.

Roy Lewallen, W7EL