Re: [Discuss-gnuradio] FM Receiver doesn't work

[West, Nathan]

On Wed, Feb 19, 2014 at 12:46 AM, stephan vanwoezik
<address@hidden> wrote:
> Hello,
> My system: WBX motherboard, B100, 2007 Macbook Pro 10.8.5 2.4 ghz core duo
> 4gb 1067mhz ddr3.
>
> I am new here. I have tried to build several FM receiver flow graphs - Taken
> from the Ettus website, Ettus Youtube page and other sources too. I get the
> same problem every time... no signal past the wbfm receiver. I am convinced
> it must be something with the wbfm receiver block. Ettus tech support  guys
> had me investigate sample rates and WX vs QT components, so I reduced sample
> rates as much as possible and ran both WX and QT configurations with no
> change.
>
> I've gotten simple flow graph examples to output audio and every block that
> I've tried seems to do something except wbfm receiver. The Ettus guys were
> able to run my flowgraph (with audio output from wbfm receiver) when I
> emailed it. I just updated everything on macports and the issue still
> persists. What can I be doing wrong? I won't attach a file until someone
> asks me to, since I'm not familiar with etiquette.
> Thanks,
>
> Stephan Vanwoezik
> address@hidden
> www.trapadulli.com
> Delray Beach, FL 33444
> (310)210-3814
> Stephan Vanwoezik
> address@hidden
> www.trapadulli.com
> Delray Beach, FL 33444
> (310)210-3814
>

What version of GNU Radio are you running (check with
gnuradio-config-info -v). There was a bug that crept in to the
fast_atan2f function (it was my fault and I've been seriously
regretting it...) in the latest release that was fixed about a week
after it was introduced. The symptoms are most noticeable when
receiving low power FM signals since you get all 0s out.

See this thread for more details:
http://lists.gnu.org/archive/html/discuss-gnuradio/2013-11/msg00514.html

Nathan