Hi Marcus, The degradation was 40 dB relative to expected. My measurements were ballpark. For an indication of the Minimum Discernible Signal, I looked at when a signal fell below the noise in a QT QUI Sink (FFT 32K, 570K sampling rate). The same test with an Ettus B200mini showed the minimum discernible signal was better than -120 dBm. Doing the same test with LimeSuiteGUI (the Lime test/control suite) with the Lime Mini showed a minimum discernible signal better than -120 dBm.
A published comparative review (that seemed to use a good measurement approach) gave the LimeSDR Mini a Noise Figure of around 10 dB ( gitlab.com/librespacefoundation/sdrmakerspace/sdreval ( http://gitlab.com/librespacefoundation/sdrmakerspace/sdreval ) ). Today I’ve found that the deprecated gr-soapy source works fine with the LimeSDR Mini. I see Rx performance (with GR) at about the same level as with LineSuiteGUI. I did need to change Ch0: Antenna to LNAH. >From examining the yml for gr-limesdr-source and the generated py code, >gr-limesdr-source seems to be missing provision for some parameters including >the antenna. The default is apparently not correct for a LimeSDR Mini. LNAH >for Antenna works for me. I expect that editing the generated py file would be OK as a workaround, but it is easier for the moment to use the deprecated block. I see that there are some variations in the LimeSDR family of devices that might affect writing a generic LimeSDR source block ( wiki.myriadrf.org/Gr-limesdr_Plugin_for_GNURadio ( http://wiki.myriadrf.org/Gr-limesdr_Plugin_for_GNURadio ) ). Tx is Work In Progress. Dave > > > > Hi Dave, I'm not an expert on the Lime hardware, but I could see how > different filter, gain etc configurations would lead to different > performance. Can you explain what exactly you mean with "degraded > performance"? Best, Marcus > > > > On 4/10/25 6:59 AM, dave_a...@bigpond.com wrote: > I have a LimeSDR Mini > 2.4.When I test Rx performance using the LimeSuiteGUI, I see > performance > in line with the device specifications.With GNU Radio 3.10.1.1 under > Ubuntu > 22.04.5, the performance is severely degraded.The GR test is a > simple flowgraph of a Soapy > LimeSDR Sink into a QT GUI Sink. > >
