[GreenKeys] on-off radio teletype (not FSK)

[Robert Downs]

I would say "less likely" rather than "unlikely" but selective fading was
why I disagreed with the statement in an earlier post that wide shift was
found to be unsatisfactory on HF but narrow shift worked just fine.  With a
converter capable of copying mark-only and space-only you have a frequency
diversity system that uses only one receiver and one antenna.  It would
probably perform better that a narrow shift system under frequency selective
fading conditions.

Robert Downs - Houston
WA5CAB


-----Original Message-----
From: greenkeys-bounces at mailman.qth.net
[mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of Jim Haynes

Another reason for 850 Hz shift, realized later, is that the two tones can
be detected separately and the detector outputs combined, giving the effect
of frequency diversity.  It was unlikely that both frequencies would fade at
the same time.