GQRX vs SDR Console different SNR readings?

  • Hi, after some troubleshooting I have a very strange conclusion about the SNR displayed on the spectrum on GQRX and SDR Console:
    All SNR are read by looking on the grid background and the index on the side, so there is a certain tolerance.

    On gqrx I get around 16-20 dB on the CW beacon when it is on it's peak. Without changing the dish position, bias-tee voltage or sdr, I switch from Linux to Windows an start SDR Console. In there I can read a SNR of around 25dB to 32db which keeps me wondering why the SNR is different in two other applications without changing the hardware.
    Did anyone of you experience the same issue?


  • Hi,

    yeah, the SNR calculations are different but I did not use them. I just looked on the height of the signals in the spectrum display and did not read any calculations. I'll upload two pictures which describe the phenomenon in a few minutes

  • Ah, so while taking pictures I might have found a solution to the "problem":

    GQRX and SDRConsole seem to use different styles of displaying the spectrum:

    GQRX has very small steep lines also when zoomed out and also updates very quickly which leads to belive that the SNR lower. I had to trigger the screenshot exactly right to get this SNR, which comes far closer to the one in SDRConsole.

    SDRConsole has a smoother and slower change on the spectrum display which makes seeing the peaks easier. There is also some kind of "smoothing" which decreases when zooming which leads to assuming that the Noise floor is lower. When zooming in this "smoothing" disappears.

    So all in all it is a matter of zoom level and the difference in displaying style.
    Sorry for bothering but maybe someone will have this "issue" to in the future.