AFRICAM V2.1

Version 2.1 adds support for ET3 encoding (32-bit frames).
Also we can now decode ET BPSK frames transmitted either differentially
(the traditional standard) or non-differentially.  The non-differential
mode is called PSKL.  Non-differential transmission is more robust in
noise but does introduce a 2-way ambiguity in the reference phase.  The
FLIP button can manually invert this reference value - you'll have to
re-sync afterwards.  Differential encoding is probably still best for weak signals in white noise.

This program is intended for receiving what has become known as BPSK.
It's a weak-signal mode mostly used on the lower band.  It's actually
"differential-mark" BPSK.