But surely, when narrowband filtering is in place - as any narrow
band mode will of necessity be doing internally - any wideband non Gaussian or
bursty noise when applied to this narrow filter will eventually become
Gaussian IN THAT BANDWIDTH
We first ealised this in teh original QRSS tests with G3PLX back in the
1990's. 73kHz was full of spikes and 'crud' from teh then existing
Decca signals and other stuff. But when Peter examined the output from
the narrow filters, (the FFT bins) it lookdd like, and appeared to show
itself to be Gaussian. He said it passed the tests for Gaussian
noise
A mathematician could probably prove that any random non Gaussian signal
if filtered sufficiently narrow in comparison to itsnature, would end up
Gaussian in the filtered bandwidth.
In fact, to end up non-Gaussian, it would have to have definite
components repeating at rates very close to the reciprocal of the bandwidth of
the filter.
Andy G4JNT
