I doubt you've missed something basic! I don't know what I'm doing!
I followed Brian's suggestions - but then also changed to 24khz audio out
to see if that would help.
So a decimate by 2 and then 20, so 960khz / 40 = 24khz.
I should also mention that I have poor reliability with limesdr. It lasts
for 5 minutes at most before needing a restart, and needs constant
firmware reflashing. So this could also be an issue.
On 6 March 2018 at 17:20, Adrian Musceac <kanto...@gmail.com> wrote:
> Hi Matt,
> Perhaps I'm missing something very basic, but I fail to see how you
> reached the numbers for the sample rates. They look wrong to me. 1
> Msps -> decimation by 4 -> 960 Ksps?
> Regarding performance, I'd say some optimization is required for
> better performance. I was able to demodulate WFM with gnuradio on a
> 1.2 GHz ARM mobile phone with plenty of CPU to spare (50% or more).
> I can give you a flowgraph if you want, but it's C++ code not GRC.
> On 3/6/18, matthew venn <m...@mattvenn.net> wrote:
> > Hi Brian and Adrian, thanks for the help.
> > we've finally gotten around to having another go with gnuradio.
> > Brian, I tried your settings and we have the same situation. Things work
> > fine until we adjust the tuning, then something happens. There is still
> > some crackling from the speakers, but
> > we can never get the sound back, even if we retune to exactly where we
> > started.
> > Attached is the new patch, and the errors that get printed when we tune.
> > One thing that has changed is there is no aU errors anymore.
> > Regarding hardware, it's the LimeSDR. My PC is 6 core 3ghz FX6100 with
> > ram. It hits 50% on one core with gnuradio companion running. When
> tuning I
> > don't notice a difference.
> > Thanks!
> > Matt
> > On 16 February 2018 at 22:42, Adrian Musceac <kanto...@gmail.com> wrote:
> >> Hi,
> >> Based on your graph, the filter seems to be running at the same sample
> >> rate as the source, even though you have a decimator block ahead of it.
> >> I suggest to correct that and then try again.
> >> Cheers,
> >> Adrian
> >> On February 16, 2018 8:42:13 PM UTC, matthew venn <m...@mattvenn.net>
> >> wrote:
> >>> Hi all,
> >>> I've got a limesdr that I'm using to learn about SDR. I started with
> >>> AM tutorial from the website and have now moved on to something that I
> >>> can
> >>> pickup with an antenna.
> >>> The flow works, until I tune it. Then I get aU on the log, and the
> >>> changes (it still makes noise), but I can never get the audio back even
> >>> if
> >>> I retune to exactly where it was.
> >>> I can use the waterfall to find a new frequency, then stop the flow,
> >>> type
> >>> that new number as the default tuning and then start and hear audio
> >>> again.
> >>> Until I tune...
> >>> Any idea why it breaks the audio when I tune it?
> >>> Thanks,
> >>> Matt
> > --
> > Matthew Venn
> > web mattvenn.net twitter @matthewvenn <https://twitter.com/matthewvenn>
web mattvenn.net twitter @matthewvenn <https://twitter.com/matthewvenn>
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