NFM suggestions for noise reduction and filter

[guidomartino]

hi, regarding NFM listening both of communications in general and communications in amateur radio bands (e.g. in the 2 meter band) what configurations do you use as filter width and above all as noise reduction? I am using for the 2 meter band a filter width of 10 or 12 kHz and as noise reduction Nr2 medioum uppure Nr4 reduction 6 db smoothing 40% rescale 2 db...suggestions? THANKS!!!

[guidomartino]

... nothing?..What noise reduction setting do you use for example in the 2 meter amateur radio band?

[Max]

... nothing?..What noise reduction setting do you use for example in the 2 meter amateur radio band?

Personally I don't use NR at all for the most part. If I have a reasonably strong SSB signal then I do use NR5 sometimes as it works very well to produce "armchair copy".

However, just listened to some local NFM (Airspy HF+) as an experiment. The odd thing is with your recordings on your original post, you say you were using no NR for the buzzing SDRC recording. Oddly I can get a similar sort of "buzzing" to your recording when using NR2 and tuning off the signal slightly. Here's a link to a video of what I heard, also demonstration tuning off frequency with NR4 (no noticeable issues):

https://drive.google.com/file/d/1lCWIBw ... sp=sharing

With no NR selected I do not here any buzzing at all even if tuned off frequency.

With regard to NR settings, I don't have any rules (on the rare occasions I use NR). Just always set to whatever sounds best on that particular signal. So many variables.

73

Max

[guidomartino]

Thanks!!

[guidomartino]

...is it possible that the noise reductions are significantly different than in SDR#?...Sometimes what is barely perceptible in SDR Console (trying various NR settings) becomes intelligible with SDR# (again using IF NR and Audio NR)

[Max]

...is it possible that the noise reductions are significantly different than in SDR#?...Sometimes what is barely perceptible in SDR Console (trying various NR settings) becomes intelligible with SDR# (again using IF NR and Audio NR)

I'm no expert (very far from it) but it seems to me from observation and reading people's comments in the groups that the noise reduction algorithms and methods across different software vary widely. It's one area that I think perhaps does not bear comparison very easily across platforms. Anyway, I can believe what you say regarding SDR#. Yousef (like Simon) is a very clever guy. However, as a usable piece of software IMHO SDRC is far superior as a daily listening tool. After using SDRC I find every other SDR software I've used hard work ergonomically.

I did download and try a copy of Thetis which is widely lauded as software for the Hermes Lite 2. Reason for my interest was people being hugely complimentary about one of the noise reductions on the software. I felt they were quite right. From a quick test it is extremely good. Trouble is that the ergonomics of the software are not anything like as good as SDR Console and to me the waterfall display is crude in the extreme. Also the tuning ergonomics are (to me) very hard work and counter intuitive. As I mentioned, I'm not a great user of NR anyway, so it's straight back to SDRC for me.

73

Max