Hi Cinaed, But this is without the actual LimeSDR sink block? Or with it?
Because, I can produce a clean sinewave with a HackRF, but not the LimeSDR. On Sun, Mar 21, 2021 at 1:07 AM Cinaed Simson <cinaed.sim...@gmail.com> wrote: > Hi Anish - I think I may have found the problem. > > When the complex rational resampler is on the out put of the WBFM, it > bothered me later that I couldn't see the top of the signal. > > The scale on QT GUI SINK was clipping the signal but not the computational > noise. > > In the QT GUI SINK, if I set the Y-min to be -99 and Y-max to be 0, the > signal looks perfect. > > And if the receiving RTL dongle has noise while listening, it may be a DC > offset problem. > > -- Cinaed > > > On 3/18/21 6:58 AM, Anish Mangal wrote: > > Here are two debug logs from LimeSuite GUI. In one, I load the settings > that gnuradio does to the limesdr and see the debug log. The other is the > settings file which the sdrangel writes. > > If I diff them, among other differences, this is what I see in the end of > the sdrangel-debug-log > DEBUG: Selected: VCOL > DEBUG: csw 169; interval [166, 172] > DEBUG: M=195, N=3, Fvco=1300.000 MHz > > And this is what I see in the gnuradio-debug-log > DEBUG: Selected: VCOM > DEBUG: csw 174; interval [171, 177] > > Now, I'm *very* new to this.. but could it mean that different VCOs are > used in both cases, and in the case of gnuradio, it maybe has some issues > to stabilize to some freq? > > On Thu, Mar 18, 2021 at 7:12 PM Christophe Seguinot < > christophe.segui...@orange.fr> wrote: > >> Hi all >> >> There is something wrong in this simulation. >> >> Attached is a flowgraph with a selectable Lime SDR Source, and a RTL-SDR >> dongle as receiver. I tested this with a Lime SDR Mini. >> >> - I was suspecting a Lime SDR issue, however this is not so clear. >> - As Anish I also tested a const source. >> - The flowgraph is running fluently and I dont' see any error message >> about transmission to Lime SDR >> >> Conclusion of my simulations : >> >> - with a const source (=1) at Lime input : everything is OK, the >> received signal is frequency shifted (normal) and the SNR is correct if >> LimeSDR Gain is sufficient >> - Using ratioanal resampler followed by WBFM Transmit Same reslt, >> everything is OK >> - First source+ WBFM + Rational resampler (this is a sample file >> found on LimeSDR website >> - the spectrum is not correct (look like a modulated signal >> - the received signal magnitude is not constant >> - >> *BUT the send signal on the Time Sink look like correct. ( I.E =1+j0 as >> for others sources, whitout any glicht) * >> >> How can we further investigate this? >> >> >> On 18/03/2021 13:13, Anish Mangal wrote: >> >> And, if I try the attach gnuradio file, which is just a constant source >> of value '1' going to the limesdr sink block, I actually see a sine-ish >> wave without the glitchy behavior. >> >> On Thu, Mar 18, 2021 at 5:31 PM Anish Mangal <anis...@umich.edu> wrote: >> >>> I tried your grc and got the same result. >>> >>> See the waveform's envelope in this oscilloscope capture. Note the >>> timebase. >>> >>> https://drive.google.com/file/d/1b7PnpmvFfdQTDIwALuOzb22AzeffzR2w/view?usp=sharing >>> >>> This isn't happening in SDRAngel. >>> >>> On Thu, Mar 18, 2021 at 3:49 AM Cinaed Simson <cinaed.sim...@gmail.com> >>> wrote: >>> >>>> I moved the rational resampler block from the output side to the input >>>> side of the WBFM. >>>> >>>> The output of WBFM block needs to match the input of your LimeSDR. >>>> >>>> I don't have the LimeSDR software installed so I couldn't look inside >>>> the sink block. >>>> >>>> -- Cinaed >>>> >>>> P.S - yes, you can post GRC's on the mailing list - they're text based. >>>> >>>> >>>> On 3/17/21 4:14 AM, Anish Mangal wrote: >>>> >>>> I linked >>>> <https://drive.google.com/file/d/1xQz1Kp_feAO1YrZRXXnMF25XEGgqVPSw/view?usp=sharing> >>>> the grc file in the original email. Attaching it here as well. (Don't know >>>> if the mailing list allows attachments) >>>> >>>> >>>> >>>> On Wed, Mar 17, 2021 at 1:40 PM Cinaed Simson <cinaed.sim...@gmail.com> >>>> wrote: >>>> >>>>> >>>>> Hi Anish - since this is a gnuradio mailing list, the starting point >>>>> would be to post your GRC - which is an yaml or text file. >>>>> >>>>> -- Cinaed >>>>> >>>>> On 3/16/21 11:19 PM, Anish Mangal wrote: >>>>> >>>>> Hi! Any pointers to where I can start debugging this? >>>>> >>>>> Maybe run gnuradio-companion in debug mode? >>>>> Do more simpler tests? >>>>> Any other suggestions? >>>>> >>>>> I have a HackRF One and will try the exact same comparison there too >>>>> ... SDRAngel & grc >>>>> >>>>> On Mon, Mar 15, 2021 at 7:32 PM Anish Mangal <anis...@umich.edu> >>>>> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> To properly explain the issue I'm facing, I recorded a video showing >>>>>> Oscilloscope waveforms. >>>>>> >>>>>> >>>>>> https://drive.google.com/file/d/11anGShu-I3NhL9Jet6YAiyBprvwP4kDc/view?usp=sharing >>>>>> >>>>>> The gnuradio flowgraph is here: >>>>>> >>>>>> https://drive.google.com/file/d/1xQz1Kp_feAO1YrZRXXnMF25XEGgqVPSw/view?usp=sharing >>>>>> >>>>>> The various versions of the software/hardware involved are the >>>>>> following. >>>>>> >>>>>> gnuradio-companion: 3.8.2.0 (Python 3.6.9) >>>>>> gr-limesdr: branch gr-3.8 (last commit >>>>>> 47511dd58de1695b70e1028366411bada85eb60f) >>>>>> sdrangel: 4.12.1 >>>>>> OS: Linux Mint 19.1 >>>>>> CPU: Intel© Core™ i7-4900MQ CPU @ 2.80GHz × 4 >>>>>> RAM: 16GB >>>>>> H/w: Thinkpad T440p >>>>>> >>>>>> tl;dr >>>>>> I'm trying a simple test to create a sinewave output from a WFM >>>>>> modulator block. If there is no audio input, its WFM modulated signal >>>>>> should be a simple sinewave. If I test this with SDRAngel, I see a >>>>>> clean-ish actual sinewave in time domain on the oscilloscope. But if I >>>>>> try >>>>>> to do the same with gnuradio, it seems to produce a glitchy signal. >>>>>> >>>>>> Could I have any advice on what I might be doing wrong? >>>>>> >>>>>> Thanks, >>>>>> Anish // VU2TVE >>>>>> >>>>> >>>>> >>>> >
