I found the below uhd_two_tone_loopback example (which is one of the gnuradio provided examples) and I am trying to run it, it runs but I can't receive signal.


I mean when I run the program I cannot hear the audio tone at all. If I connect an audio sink to the TX side I hear the audio. But when the audio sink is connected to the output port of the USRP source I can't hear the audio tone.

So, I have the b200 mini usrp and I am connecting the TX to the RX using an FW-10+ 10 dB attenuator.

What could be the problem that I can't get the loop working? Thanks.


enter image description here

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    $\begingroup$ Please be more specific — there are in general many different ways for things not to work. When you say "can't receive signal", what do you observe? What do you hear, and what do you see in the frequency sink? Edit your question to describe these observations. $\endgroup$ – Kevin Reid AG6YO Sep 3 '19 at 1:21
  • $\begingroup$ @KevinReidAG6YO, Thanks Kevin. Thread is updated. $\endgroup$ – Hadad Sep 3 '19 at 1:34
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    $\begingroup$ @Hadad more own debugging! What's the amplitude of the received signal? Do you see the sine in the spectrum display, as you'd expect? Why are you using a sampling rate that is at the very lowest border of what the USRP can do? How are you making sure sampling rates in this system match (hint: they don't, and you should be getting a lot of errors after a short time). $\endgroup$ – Marcus Müller Sep 3 '19 at 7:42

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