Thanks Martin, Thanks for the idea... and, yes, 1kHz for audio stop isn't a good idea. I've reinstalled the 3.2.2 and it really works fine. Anyway, I'll be trying to do a filter as you recommended.
Thanks! Bernardo On Tue, Mar 1, 2011 at 5:54 AM, Martin Braun <martin.br...@kit.edu> wrote: > Hi Bernardo, > > I'm pretty sure the filter code hasn't changed too much since 3.2.2. > However, I'm surprised it worked before: Your FM demodulator requires a > pretty steep filter (the transition width is less than 0.005 normalised > to the sampling frequency). I only had a quick peek, but since your > decimation in the FM demod is 1, you could use a frequency demod instead > and couple it with your own (custom) filter. > The gr_remez code is a bit unstable in this respect. You normally have > to fiddle around with the parameters until you get a good filter, and > the FM demod block doesn't give you enough knobs. > > MB > > > On Mon, Feb 28, 2011 at 11:25:54AM -0300, Bernardo Guadagnin Gonçalves > wrote: > > Hello, > > > > > > Until last week I was using the Gnu Radio 3.2.2 (which is ready for use > in > > ubuntu), then I decided to try the latest version > (v3.3.1git-147-g5a23954a). > > The flowgraph was working perfectly. It's for "in" GRC simulation only. I > know > > it's very simple and the 38kHz recovery (at the receiver) is not the > > recommended way. > > > > > > Flowgraph: http://dl.dropbox.com/u/8898915/FMstereotxrx2.grc > > > > .Wav for simulation: http://dl.dropbox.com/u/8898915/sine4k.wav > > > > > > The messages that are now shown are: > > > > > > Showing: "/home/mula/Dropbox/Public/FMstereotxrx2.grc" > > > > > > Generating: "/home/mula/Dropbox/Public/top_block.py" > > > > > > Executing: "/home/mula/Dropbox/Public/top_block.py" > > > > > > gr_remez: insufficient extremals -- cannot continue > > > > Traceback (most recent call last): > > > > File "/home/mula/Dropbox/Public/top_block.py", line 361, in <module> > > > > tb = top_block() > > > > File "/home/mula/Dropbox/Public/top_block.py", line 193, in __init__ > > > > tau=tau, > > > > File > "/usr/local/lib/python2.6/dist-packages/gnuradio/blks2impl/fm_demod.py", > > line 65, in __init__ > > > > 60) # Stopband attenuation > > > > File "/usr/local/lib/python2.6/dist-packages/gnuradio/optfir.py", line > 53, in > > low_pass > > > > taps = gr.remez (n + nextra_taps, fo, ao, w, "bandpass") > > > > File "/usr/local/lib/python2.6/dist-packages/gnuradio/gr/ > > gnuradio_swig_py_general.py", line 432, in remez > > > > return _gnuradio_swig_py_general.remez(*args, **kwargs) > > > > RuntimeError: gr_remez: insufficient extremals -- cannot continue > > > > > > >>> Done > > > > > > Thanks! > > > > > > Regards, > > Bernardo > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > -- > Karlsruhe Institute of Technology (KIT) > Communications Engineering Lab (CEL) > > Dipl.-Ing. Martin Braun > Research Associate > > Kaiserstraße 12 > Building 05.01 > 76131 Karlsruhe > > Phone: +49 721 608-43790 > Fax: +49 721 608-46071 > www.cel.kit.edu > > KIT -- University of the State of Baden-Württemberg and > National Laboratory of the Helmholtz Association > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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