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Spurious signals of Adalm-Pluto


I recently purchased an Adalm-Pluto and started the first tests. As an initial test I used Adalm-Pluto for receiving the linear transponder of the Qatar-Oscar 100 geostationary satellite. I compared Adalm-Pluto signal reception with those of SDRPlay RSPDuo and a simple RTL-SDR usb dongle. I was disappointed to notice that Adalm-Pluto produces many spurious signals, whereas the other SDR hardware doesn't show any, even the $20,- SDR-RTL usb dongle.


  1. Is there an issue with my Adalm-Pluto or have I just witnessed typical Adalm-Pluto behavior?
  2. Is there a way to illuminate the spurious signals?

The following link will give access to three screenshots of SDR Console supporting the above statements:

The screenshots show the "waterfall" of the SDR Console for any of the three tested SDR hardware components. Then observe that the waterfall of Adalm-Pluto shows many thin vertical lines, all representing spurious signals.


Thank you,

Erwin van der Linden

  • It can be difficult to compare these radios directly since they have different design purposes and configurability. From our studies we have found that AD9361 has much more sensitivity than RTL-SDR, however the external LNA on RTL does help at low signal levels.

    I would make sure that you are loading a reasonable filter for Pluto, the necessary calibrations are enabled, and you are not saturating the receiver.