Error running GQRX for the first time

[Marcelo Xavier Vieira]

Hello, I'm new to Linux and SDR technology. I have a RTL SDR (R820T) and tried to install GNU Radio from source and then GQRX from the Ubuntu Software Center. But every time I try to run the command gqrx on a terminal I come up with the following error:

linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.007.002-87-gc3acbb87

gr-osmosdr 0.1.1 (0.1.1) gnuradio 3.7.2.1
built-in source types: file osmosdr fcd rtl rtl_tcp uhd hackrf bladerf rfspace
gqrx: symbol lookup error: /usr/lib/x86_64-linux-gnu/libgnuradio-osmosdr.so.0.0.0: undefined symbol: _ZN3uhd6device4findERKNS_13device_addr_tE

What can I do? What's wrong? I even tried to uninstall all the GNU Radio related packages, but the error is still the same...

Thanks.

[grege...@gmail.com]

Hi Marcelo,

If you install Gnuradio first, and if it is the wrong version of Gnuradio for the version of GQRX you are installing, it is difficult to get all of the Gnuradio components uninstalled.

Try this:

Start with a clean install of an Ubuntu based distro, such as Ubuntu, Xubuntu or Linux Mint.

Do NOT install or compile Gnuradio on this machine.

Add the GQRX Releases PPA to your software sources  (See gqrx.dk website).

Install the current GQRX release (2.3.1?) from the PPA with your software manager.  It will grab the Gnuradio components that it needs.

[Marcelo Xavier Vieira]

Thank you very much, Greg! 

Now it's working with a clean install of Linux Mint. Fantastic!

I'm just wondering how to receive some low frequency signals (40 meter band, for example) with a Ham-it-Up. I've read here on this forum that is something related to the LNB LO option. But I didn't quite understand what value I need to put there... -125 MHz? 

Can you explain that to me, please?

Thanks!

[grege...@gmail.com]

I've never used one, but it looks like you can just tune to the freq you want plus 125 MHz.  So if you wanted to listen to 7.2 MHz you would tune to 132.2 MHz.  Setting the LO in Gqrx to 125 MHz would let you just tune to 7.2 and not do the math.

Greg

[simo...@gmail.com]

I have the same problem :(

:~/Desktop$ gqrx
linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.008.002-161-g1f41782b

gr-osmosdr 0.1.1 (0.1.1) gnuradio 3.7.2.1

built-in source types: file osmosdr fcd rtl rtl_tcp uhd hackrf bladerf rfspace
gqrx: symbol lookup error: /usr/lib/x86_64-linux-gnu/libgnuradio-osmosdr.so.0.0.0: undefined symbol: _ZN3uhd6device4findERKNS_13device_addr_tE

How can I solve this? I don't want to reinstall my OS to get it to work :(
Thank you

[Jose Perez Junior]

I have the same problem of Simone.. someone can help?

[George Vrinchev]

I have the same RTL stick
idVendor=0bda, idProduct=2838
New USB device strings: Mfr=1, Product=2, SerialNumber=3
Product: RTL2838UHIDIR
Rafaelo R820T
I install/remove(purge) few times the GNU radio and gqrx-sdr, and get the same errore as all of you above cited.

gqrx: symbol lookup error: /usr/lib/x86_64-linux-gnu/libgnuradio-osmosdr.so.0.0.0: undefined symbol: _ZN3uhd6device4findERKNS_13device_addr_tE

The API crashes when I try to chnge the settings of the SDR, and this errore seems that is the signature which gqrx is looking for when started, or trying to change into it configuration.
I think that something in the installation is wrong, or PGP is not corectly installed in installation progress.

I will appreciate all hints, tips or tricks.
thanks in advance
tedy58

[Stack Programer]

in installing linux ubuntu  gnuradio (download from gnuradio.org)live 14.04  it returns errors:
there is a version gqrx and gnuradio on it,but i unistall them ,i install again with apt-get install gqrx-sdr
it has errors///////

uilt-in source types: file osmosdr fcd rtl rtl_tcp uhd hackrf bladerf rfspace

./gqrx: symbol lookup error: /usr/lib/x86_64-linux-gnu/

libgnuradio-osmosdr.so.0.0.0: undefined symbol: _ZN3uhd6device4findERKNS_13device_addr_tE

[David Ranch]

Unless you're willing to compile everything from scratch, you should not mix source-built and pre-built binaries for use with Gqrx.  Instead, it's recommend you follow this guideline:

   http://gqrx.dk/download/install-ubuntu

It's *critical* that you uninstall / delete all of the previous GnuRadio and other programs you might have installed on your machine first.  If you cannot delete all of those program fragments properly, Gqrx might never run properly.

--David
KI6ZHD