I wrote:
> A trained human ear has ~50 Hz bandwidth so it is
> fairly easy to separate multiple signals even inside
> 1000 Hz bandwidth. This is how the guys who win the
> Dayton pileups do it (e.g. K3ZO)...and they are also
> good at copying multiple signals on different frequencies
> simultaneously. Programs like Morse Runner are excellent
> practice for this if you need to improve your ear/brain's
> DSP.
W9WI replied:
>And that *can* work fairly well, but merely being able to
copy multiple signals through the QRM doesn't help that much
if the *other guy* doesn't have the same ability...
But a caller doesn't need to. He is answering
*your* CQ. He may have taken minutes to tune you in
very carefully with a 100 Hz filter and code-reading
software before he called. On the other hand the
runner must be prepared to copy stations answering
+/- 500 Hz off his running frequency, whether due to
the caller being "tone deaf", accidentally leaving his
RIT on, or whatever...and the runner must respond very
quickly (which precludes ultra-narrow filters). I
have even answered some callers that are outside a
1000 Hz passband when I could copy their clicks or
phase noise! As I said before, forget about this
trick in extremely crowded contests like CQ 160 CW.
73, Bill W4ZV
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