svn co svn co https://www.cgran.org/svn/projects/multimode/trunk/ gnuradio-multimode
git clone git://git.osmocom.org/osmo-sdr.git
On arch linux, a working package is in aur so you only need
yaourt -S gnuradio
* Use Multimode
./multimode.py --devinfo=rtl_tcp=foo.fixme.ch:1234 --freq=98.5M --dmode=WFM --mthresh=-35 --vol=10