You'll likely find that there is no silver bullet and that you end up having to approach various bands and modes differently. That said, the threshold effect of even narrowband FM is just about the best thing you have going for you
True, that. In fact, learning more about my 7100, I will do some reception testing with the FM bandwidth filter set to the narrowest which is 7K. Using my SDR I discovered there is a narrow noise peak a MHz or two below my desired repeater RX frequency. Not sure if that is a culprit or not.
: although an inconvenient truth, it's a truth nonetheless that improving the signal-to-noise ratio prior to demodulation is a sound starting point and the gains from that will pay more than proportional s/n gains in the demodulated FM. So, the suggestion of a directional antenna to improve the s/n is a good one, particularly for FM. If you were starting with a blank sheet (which presumably you're not) I'd also recommend a closer look at the FM receiver you're using: some have much better limiters and demodulators than others.
I use a CLRdsp unit, amongst other coherent and baseband processors in my station. Leaving aside the much better returns from time invested in things like LF/MF/HF receive antennas, good common mode choking and (where possible) noise source suppression, I rate the CLRdsp unit as somewhat useful, without being outstanding. The most successful application is with HF SSB using vintage receivers. With no receiver DSP, my first and usually most successful weapon is to use what the receiver offers in the way of noise limiting (IF clipping), noise blanking (in newer classic receivers), and passband modification (via internal/external filters and/or passband shift/notch controls). The baseband DSP processors sometimes, but not always, help somewhat beyond that.
When you get the CLRdsp give it a run over a day or two and see if you think it helps beyond some useful tonal modification. I seem to remember that it uses a bridge audio output so follow the manufacturer's instructions regarding not grounding one side of the speaker; that was a minor hassle in my shack with multiple audio devices but it's easily addressed.
73, Peter.
Thanks. Yes, being one who likes to play with new stuff, I found a good reason to go to my local O'Reilly's Auto Parts store to buy a pack of five 2 amp fuses for $4.99. In spite of the User Manual having a clear warning about "not grounding" and your statement above, of course I had to try to hook up my powered Klipsch speaker to the CLRdsp. Two fuses later, I learned what works and what doesn't. Some of us are either a) slower learners, or b) like to see if warnings are REALLY true. I was happy that there was a fuse inside.
While my testing of the CLRdsp is not complete yet (I have a test session later this morning with another ham) here are my preliminary thoughts.
1. As expected, the immediate accessibility of the controls for degree of NR as well as the tone control (bringing up the highs suppressed by NR) is very useful and appreciated.
2. Regarding noise/static reduction on "mildly" staticy RX, there is a "slight" adavantage of the CLRdsp over the facility in the 7100. And my experience, despite some opinions to the contrary, is that a combination of the 7100 NR and the CLRdsp NR - in moderation - can result in an overall improvement.
3. On severely staticy RX where voice is buried in the static such that Readability is 1 or 2, the jury is still out and subject to more testing.
I remain curious how the Xiegu GNR1 or the bhi dsp units stack up against the West Mountain CLRdsp. I suspect they are within a gnats eyelash of one another (technical measurement). Curious minds can be a PITA.
And thanks, Peter, 73s
Jerry