JIMMIE wrote:

But aside from that little foray, I have no doubt that the effects that
call for diversity antennas/receivers also call for some physical
separation of separate antennas.

- 73 de Mike N3LI -

When I was an ET in the Air Force I had a TDY assignment attached to a
project with Hughes. They were attempting to to implement in software
what Tom was doing in wetware. The purpose was to send high speed(at
the time) radar data over HF SSB . The project was a success but the
final implementation was very different from "stereo diversity"
basically because they could not program a computer to do what the
brain can do very easily.

these days, though, it's pretty straightforward.. The whiz-bang MIMO
stuff you see in 802.11n, for instance is one flavor of diversity. Two
antennas at each end gives you 4 possible paths (A:1, A:2, B:1, B:2)
each of which will have different fading and interference properties.