Dave J. wrote:

Just out of interest, how long has diversity encoding been around? I
thought of it as relatively modern, and I've only read about it from the
POV of digital signals. Is there anywhere anyone'd recommend for a bit of
research? Something semi chronological would be nice.

Back to the thirties at least. Earlier diversity systems were comparatively
crude, though, normally just looking at two antenna systems separated in
space or in polarization and picking the one with the higher AGC voltage.
This can give a remarkable improvement in dealing with ionospheric fading,
though. Was standard practice for remote shortwave links on broadcast
networks.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."