Re: LimeSDR USB parameter help

[Christophe Seguinot]

First investigate if your problem is related to LimeSDR source. Simply connect a time sink to the output of thee Lime Source. Autoscale to see if the signal is present .

In one of my attempt, this signal was very low and has only 2 different values like a binary noise. In that case, the spectrum do not exhibit a maximum at the radio station frequency.

Did you set the LimeSDR Gain to a large value (up tu 70 dB for the LimeSDR Mini)

On 29/01/2020 23:41, jane wrote:

hi, Christophe Seguinot

i have downloaded your .grc file.

i ran it on my laptop with changing audio sink to 44.1, 32, 24. Of course, freq is a fm radio in my area. But i still saw aUaUaU. i heard noise only.

my info is:

hardware: Limesdr USB

OS: ubuntu18.04

gnuradio: 3.8.0.0

gr-limesdr: gr-3.8 

LimeSuite: v19.04.1-ga5b3a10f

and i also do as gracid said: https://github.com/myriadrf/gr-limesdr/issues/55

1. I see that I've left the default value of "ok to block" in the audio sink, set it to "No" and leave it like that.
2. Try different audio sink rates, for that you would need to change rational resampler and quadrature values (44.1k example: Decimation=2000, Interpolation 441, Quadrature rate: 441e3).
3. Try adding a couple seconds of delay by inserting "Delay" block just before audio sink.

I really didnt know why it did not work.

i saw @Christophe Seguinot said :In the meantime, I used LimeSuiteGui to calibrate the LimeSDR Mini receiver. Don't know if that step was requested, but it now works!

how to calibrate the LimeSDR USB?

Is there anybody who can give other recommendations for my case?

I am not sure if gnuradio3.7 is ok. But i have no confidence with it.