# GNU Radio Companion QT GUI Window Quit Immediately

**URL:** <https://www.ruby-forum.com/t/gnu-radio-companion-qt-gui-window-quit-immediately/233946>\
**Category:** GNU Radio\
**Created:** [January 24, 2015, 2:35am UTC](https://www.ruby-forum.com/t/gnu-radio-companion-qt-gui-window-quit-immediately/233946 "2015-01-24T02:35:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [January 24, 2015, 2:35am UTC](https://www.ruby-forum.com/t/gnu-radio-companion-qt-gui-window-quit-immediately/233946/1 "2015-01-24T02:35:10Z")

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Hi,

I am new to GNU Radio, so I built a FM receiver to get started on the  
journey. I created the following .grc file, and when I clicked  
\<\>,  
I saw the QT GUI window pop up and exit immediately. The sound came out  
only for less than a second and disappeared as the window sank. I’ve  
researched this problem in this forum awhile, and someone suggested it’s  
probably due to multiple versions of gnuradio installed. But I cleaned  
everything related to uhd and gnuradio in my /usr/local directories, and  
reinstalled via the script “build-gnuradio”, it still didn’t work. So  
could  
you confirm with me whether this is the reason of my problem, and if so,  
where can I check to find the conflicted version? And what do you  
suggest  
me do?

I can do uhd\_fft successfully, which opens up a window and never quit.

I am using ubuntu 14.04, usrp b210. I used “build-gnuradio” to install  
everything. It turned out that grc is 3.7.6.1, with uhd being 3.8.1

## Here’s the output of doing \<\>. It ended with “DONE”, and windows quit

linux; GNU C++ version 4.8.2; Boost\_105400;  
UHD\_003.008.001-105-g91ae742f

## – Loading firmware image: /usr/local/share/uhd/images/usrp\_b200\_fw.hex… done – Loading FPGA image: /usr/local/share/uhd/images/usrp\_b210\_fpga.bin… done – Operating over USB 3. – Detecting internal GPSDO… No GPSDO found – Initialize CODEC control… – Initialize Radio control… – Performing register loopback test… pass – Performing register loopback test… pass – Performing CODEC loopback test… pass – Performing CODEC loopback test… pass – Asking for clock rate 32.000000 MHz… – Actually got clock rate 32.000000 MHz. – Performing timer loopback test… pass – Performing timer loopback test… pass – Setting master clock rate selection to ‘automatic’. – Successfully tuned to 107.300000 MHz

Using Volk machine: avx\_64\_mmx\_orc

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<div class="post-metadata">

**Author:** ![dxi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/278dde/32.png) [@dxi](https://www.ruby-forum.com/u/dxi)\
**Post date:** [February 1, 2015, 3:27pm UTC](https://www.ruby-forum.com/t/gnu-radio-companion-qt-gui-window-quit-immediately/233946/2 "2015-02-01T15:27:53Z")

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On Fri, Jan 23, 2015 at 8:33 PM, xu shunyi [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> ## you confirm with me whether this is the reason of my problem, and if so,
> 
> – Performing register loopback test… pass  
> Using Volk machine: avx\_64\_mmx\_orc
> 
> > > > Done
> 
> * * *

Hi Xu,

Sorry for the delay on this one; I recognized the error but I really  
thought that we had already patched it. I’ve just pushed a fix for it  
that  
we’ll get merged into GNU Radio soon. It was a stray (old) call to the  
aligned version of a VOLK kernel in SpectrumGUIClass.

Tom