HF Discovery SDRC Audio Noise Reduction Setup
HF Discovery SDRC Audio Noise Reduction Setup
I'm new to using SDR radio / software. I recently purchased a HF+ Discovery, and running it with SDR Console (SDRC) v3.3 I recently downloaded. It's working great, but how do I know if I'm leveraging the proprietary noise reduction algorithm capabilities of the airspy device, as advertised on the airspy.com website? I mostly operate single sideband with this setup, and I'm using the SDRC noise reduction settings NR1 through NR5, but that is all. Are there more things I need to do?
Re: HF Discovery SDRC Audio Noise Reduction Setup
If it's truly "proprietary", I would recommend you download the Airspy SDR# software also and compare the noise reduction of both. You should find that NR5 will provide the best results with SDR Console. I'd also recommend SDR Console 3.4 over 3.3.
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Mike
Mike
Re: HF Discovery SDRC Audio Noise Reduction Setup
As Mike says, if it's proprietary to Airspy then best try SDR#.
As far as SDRC goes, I find every situation is different. IMHO what NR will never do is dig an inaudible signal out of noise. It's more a question of, if you have a good audible signal but you want to have a more relaxing signal to listen to then try one of the NRs.
I find NR5 is superb to use on a reasonably strong HF signal. It can almost totally remove any background noise and turn the signal into "armchair copy". The NRs 1-4 I find better on AM and NFM signals. I could not honestly say what to use in which situation. It's just whatever sounds best at the time. Sometimes the effect of any of the NRs creates artifacts (usually manifesting as "burbling" noises) that are too irritating to listen to, so I just prefer the original noisy signal, background noise and all.
Max
Re: HF Discovery SDRC Audio Noise Reduction Setup
Thank you both for the quick response. I'm will try SDR# next as suggested. I tried a few other apps in the past with RTL hardware, except SDR#, and so far I prefer the SDRC user interface the best.
I’m also interested in Linux SDR apps too; so far I tried GQRX. I use an external transceiver with CAT control. For that reason I prefer apps with flrig/hamlib support. Any suggestions welcome, thanks.
I’m also interested in Linux SDR apps too; so far I tried GQRX. I use an external transceiver with CAT control. For that reason I prefer apps with flrig/hamlib support. Any suggestions welcome, thanks.
Re: HF Discovery SDRC Audio Noise Reduction Setup
Thank you both for the quick response. I'll give SDR# a try next.
Re: HF Discovery SDRC Audio Noise Reduction Setup
How about a screen shot showing the spectrum at max bandwidth (912kHz) so we can see what the noise is. I.e. is it repetitious appearing every 17-25 kHz in the 75m band or thin streaks on every 10kHz from 160m through 80M. The former would be switching power supply noise, the latter would be AM BC harmonics.
I always attempt to solve the source of QRM, vs attempting to reduce or mask it using software.
As for me, I rarely use any NR on any rig (SDR or big box) due to the audio quality afterwards. HF SSB is not AM BC quality, but you will see/hear folks running 4 to 5 kHz wide on the bands. To those who are listening with standard 2.9kHz RX filter, it still sounds like SSB.
Attached is what a typical switch power supply looks like with it's repeating spikes throughout the band.
I always attempt to solve the source of QRM, vs attempting to reduce or mask it using software.
As for me, I rarely use any NR on any rig (SDR or big box) due to the audio quality afterwards. HF SSB is not AM BC quality, but you will see/hear folks running 4 to 5 kHz wide on the bands. To those who are listening with standard 2.9kHz RX filter, it still sounds like SSB.
Attached is what a typical switch power supply looks like with it's repeating spikes throughout the band.
- Attachments
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- Mysterious Switching Power Supply
- Screenshot-2025-01-19-111821.jpeg (182.98 KiB) Viewed 7413 times
73 Kriss KA1GJU Home of the KA1GJU Super Station SDRC Servers in NH, USA (FN42mw, FN43na, and FN42lt)
Re: HF Discovery SDRC Audio Noise Reduction Setup
Hi KA1GJU,
Thank you. Yes, I know about power supply noise, and other local noise problems such as LED street lights. My main rig runs on battery power (for many reasons) but initially because of issues I've had with PS (switching type PS in particular). I've even seen noise while using my battery with it connected to inexpensive battery tenders (some tenders are definitely better than others). Also, my home heater (the igniter circuit) is also a problem when it’s on.
I work a lot of DX, and I often find my self trying to work signals barely audible above the noise floor. I agree with others, there are limits to what can be achieved with noise filtering, but it helps. I also adjust the receive BW to match the signal BW as much as possible, which can help significantly. And BTW this is one of the reasons why I am starting to prefer SDRC. With SDRC, I can quickly adjust the bandwidth, asymmetrically, using the receiver waterfall as the guide posts (in a dedicated window without needing to zoom in). I have not been able to figure out how to do that with SDR#.
Per suggestions here, I’ve been playing with SDR# like I said I would. There’s a few proprietary noise reduction algorithms for AM/FM co-channel. But those don’t help me, because I operate SSB most of the time. They also have “NR5” capability available as a plugin. SDR# also has IF noise filters I find interesting. The documentation isn’t clear how they work (technically), and some have suggested they take advantage of the Airspy HF+ hardware architecture (internal HW DSP).
Regardless, I like SDRC better overall, for its UI and better external rig integration. I’m still struggling to figure out how to synch SDR# VFO with my rig, blank on XMT etc.. (not a question for this forum i suppose)
Thank you. Yes, I know about power supply noise, and other local noise problems such as LED street lights. My main rig runs on battery power (for many reasons) but initially because of issues I've had with PS (switching type PS in particular). I've even seen noise while using my battery with it connected to inexpensive battery tenders (some tenders are definitely better than others). Also, my home heater (the igniter circuit) is also a problem when it’s on.
I work a lot of DX, and I often find my self trying to work signals barely audible above the noise floor. I agree with others, there are limits to what can be achieved with noise filtering, but it helps. I also adjust the receive BW to match the signal BW as much as possible, which can help significantly. And BTW this is one of the reasons why I am starting to prefer SDRC. With SDRC, I can quickly adjust the bandwidth, asymmetrically, using the receiver waterfall as the guide posts (in a dedicated window without needing to zoom in). I have not been able to figure out how to do that with SDR#.
Per suggestions here, I’ve been playing with SDR# like I said I would. There’s a few proprietary noise reduction algorithms for AM/FM co-channel. But those don’t help me, because I operate SSB most of the time. They also have “NR5” capability available as a plugin. SDR# also has IF noise filters I find interesting. The documentation isn’t clear how they work (technically), and some have suggested they take advantage of the Airspy HF+ hardware architecture (internal HW DSP).
Regardless, I like SDRC better overall, for its UI and better external rig integration. I’m still struggling to figure out how to synch SDR# VFO with my rig, blank on XMT etc.. (not a question for this forum i suppose)