GQRX and SDRPlay RSP1A

I’ve own a SDRPlay RSP1A SDR and since I use Linux I’ve never used SDRUno, just CubicSDR that works fine with the RSP1A.

Nevertheless one thing that annoys me on CubicSdr is that we can only pipe audio out from the application, while on GQRX we can pipe data out through UDP, and hence we can pipe it out to basically anywhere and not be dependent of the audio interface and audio routing on the local PC.

But the truth is that I never was able to make GQRX to work with SDRPlay. I’ve followed some tutorials around the net such as this: http://thomasns.io/gqrx.html and this http://dk3ml.de/2019/01/12/running-sdrplay-with-gqrx-on-ubuntu-18-10/ but at the end I always had this, even with the latest versions of GQRX that support SDRPlay:

GQRX SDRPlay

While I can hear the FM station at the above frequency the frequency panadapter has a hump at the middle and that’s it, not exactly what I was expecting.

Well the issue is that GQRX at startup does not setup SDRPlay RSP1A propertly and so it shows the above behavior.

So if we get the initial GQRX settings for the SDRPlay:

SDRPlay Settings

it looks fine, but as we’ve seen the end result is not as expected. So what we need to do is to re-enter the settings again in a certain order to make this work:

  1. Stop the data capture, without exiting GQRX (press the Play button)
  2. Edit the Device settings and choose any other than SDRPlay, and then choose again SDRPlay again. Make sure Bandwidth is set to 0.6Mhz.
  3. DEfault SDRPlay Settings
  4. As we can see the default Input rate is set to 2MBps.
  5. Press Apply, and if we start the capture it should work now, but we have a RSP1A,so…
  6. Open up again the settings and change the Input Rate to the maximum that RSP1A supports: 10MBps

The end result is this:

Proper SDRPlay on GQRX

And now it works as it should.

Conclusion:
While a bit annoying it’s good to see GQRX working fine with SDRPlay RSP1A. Still through GQRX we can’t control the FM and DAB notch filters, which CubicSDR can.

5 thoughts on “GQRX and SDRPlay RSP1A

  1. Thank you very much. I didn’t know what to do. I have an RSP1 and while it works for a while (after following your instructions) then the signals is lost and i get a flat noise line at -40db or something. I will try somethings but i would like to know if you found anything more stable? or whatever. I am also using arch linux and tried also gqrx-git but nothing different.

    1. This happens with me when there is a problem with the USB connection, or if the computer is to busy doing something else. Since I’ve upgraded to a new, vwry fast computer, it only happens when there is an USB connection issue, such as messing around with the cable.

      1. My computer is a little bit old and i should try a different usb cable. I didn’t mess around with the cable (if i understand you right). Still thank you very much. Also it is fascinating to me how you find out the solution and i don’t know if anybody else knows or talks about this (couldn’t find anything about it). I have your site bookmarked and i will check it out. Thank you again

      2. I found the issue more or less by accident, so either is a faulty usb cable or usb connection, or the computer is slow. It was because of this that I’ve upgraded my computer, but kept the same graphics board. It works fine now (but I’m using Arch Linux) but when it happens is either USB related or I wass messing around with something else the stole CPU processing from the gqrx. Glad I could help.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.