> What you say about the "distortion" actually being the noise
> that had been suppressed until the cw element or ssb signal
> raised the gain is accurate.
It's easily visible in a waterfall display.
http://mysite.verizon.net/nq5t/Misc/CWgram.png
I've never really figured out if you're right in your conclusion that NR is
a downward expander, but the one thing I'm absolutely certain of is that it
adds nothing to (S+N)/N ratio, and at any BW below about 1000 Hz actually
degrades it. While it may reduce background noise during no-signal
conditions, the signal elements are buried in just as much noise with NR as
without.
I took the time to remeasure SNNR changes with NR=9 tonight, since the
subject reared its ugly and already too-beaten-to-death head again today.
These numbers are consistent (+/- a dB) with what I found the last time I
did it many weeks ago.
BW Delta SNNR (NR=9)
-----------------------------
3000 Hz + 1.0 dB
1000 Hz - 0.4 dB
500 Hz - 1.0 dB
100 Hz - 2.0 dB
Disclaimers: The usual stuff about not hating my Orion II, etc. :-)
Grant/NQ5T
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