Okay. That seems to be one of the issues. Once I move the rational resampler block to after the WBFM block, it seems to go away.
However, there is still a very perceptible difference in the quality of the signal (gnuradio v/s sdrangel), and there seems to be a lot of noise in the gnuradio-produced one. This looks like it may be a function of the settings being set on LimeSDR. I can share the settings files that I see after gnuradio and sdrangel have run, and perhaps the differences between the two could be compared. I wonder if this is the right mailing list for it. On Thu, Mar 18, 2021 at 6:00 PM Ron Economos <w...@comcast.net> wrote: > You're probably underflowing then (your CPU is not able to deliver enough > samples to the LimeSDR sink block). With the FM flow graph, reduce the > sweep time on your o-scope to see if you're actually transmitting 100% of > the time. > > Ron > On 3/18/21 05:13, 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 >>>>> >>>> >>>> >>>
gnuradio-lime-settings.ini
Description: application/wine-extension-ini
sdrangel-lime-settings.ini
Description: application/wine-extension-ini
