Anyone using GQRX in Centos-7, for SDR ?

I gave myself a toy, one of those cheap USB Software Define Radios, and
would like to use it on my C7 box. Having wasted some time on it, I gave
up and installed Ubuntu on a USB HD so I can boot that to play with SDR.
The Ubuntu GQRX installation is well documented and went off without a hitch.
but I just hate having to boot something else on my main box (partly because
it also runs a mailserver for my personal domain, partly because, well,
I just want my box running CentOS, not Ubuntu.)

Searching through SDR info on line I see someone has documented installing
all the bits for C6, but I suspect the process is different for C7.

BTW, I installed the various bits I could find from, er, I think some
came from, some perhaps from epel, on C7, but couldn't get
them to properly function.

Worse, when the USB radio is unplugged from the system, it locks up hard.

then a few days ago, I had been playing with it using the UBUNTU install,
did a reboot and for kicks fired up the GQRX on Centos, and lo and behold
it worked! I tried running it on Centos yesterday and it reverted to type,
i.e., lock up hard. I suspect that Ubuntu is leaving some hardware in a
state that allows it to work on a subsequent Centos boot (without poweroff),
but no clue what.

So, if anyone can point me to how to use it on C7, I'd greatly appreciate it.

thanks in advance!



Re: Anyone using GQRX in Centos-7, for SDR ?

By nux at 02/02/2018 - 05:38

Is it a Realtek chipset?
I've had problems with it on CentOS as the system will load up the DVB drivers (for TV tuner) thus interfering with the SDR.
What worked for me is blacklisting them & reboot. Give it a try.

cat /etc/modprobe.d/blacklist_rtl.conf
blacklist dvb_usb_rtl28xxu
blacklist rtl2832
blacklist rtl2830

BTW there's a new package at <a href="" title=""></a> if you care to test and confirm success so I can move it to the main repo.

Re: Anyone using GQRX in Centos-7, for SDR ?

By fred smith at 02/02/2018 - 16:53

On Fri, Feb 02, 2018 at 09:38:17AM +0000, Nux! wrote:
yes it is.

Ah, thanks, that's the trick. works now.

I've installed it and it seems to be working fine (based on about 20
minutes of use, and note that I"m not an expert yet).


Re: Anyone using GQRX in Centos-7, for SDR ?

By fred smith at 04/22/2018 - 18:00

On Fri, Feb 02, 2018 at 03:53:06PM -0500, Fred Smith wrote:
Nux, Im still using your gqrx and mostly its fine. but a quirk or two
that may be real bugs rather than anything to do with your build:
1. often when I exit the program after a couple of seconds I'll get
a crash report. I haven't savedit, but I can if anyone here would like
to see it.
2. occasionally when running it just suddenly stops outputting audio,
the spectrum stops showing activity and the waterfall still moves but
repeats the same row of pixels forever.

I can "fix" it by clicking the "start DSP" button twice. it may do it
again later, though.

I also notice that there's a newer version available in source. Should
you ever feel like building it, I'd be glad to give it a try.

thanks for keeping up your repo!


Re: Anyone using GQRX in Centos-7, for SDR ?

By nux at 02/03/2018 - 06:32

Cool, thanks for testing. Packages moved to main repo.