I've found that small signal detection is actually BETTER
in a wider bandwidth. i.e. ssb filters vs. cw filters for
cw sigs. Why? It's a better sample of white noise, which
the brain can average out. The CW filters either have group
phase delay which 'color' the noise, or provide distortion
such that the brain can't average it out as well.
This doesn't work where non-gaussian noise dominates...i.e. QRN.
The other thing I've noticed is that a slowly drifting signal
will stand out from noise better than one which is stable.
This raises the question of whether a synchronized TX & RX which
were slowly swept would enable s/nR improvement...much as a chopper
stabilized signal would.
Anybody versed in signal processing/signal recovery techniques
care to chime in?
n2ea
jimjarvis@ieee.org
jimjarvis@verizon.net
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