Friends:
At the AMSAT-DC Workshop on Saturday, March 23, 2013, Tom, K3IO and I demonstrated the ezcap $20 RTL-SDR SDR receiver USB dongle with GNU Radio. The ezcap device can be purchased from
http://dx.com/p/mini-dvb-t-digital-tv-usb-2-0-dongle-with-fm-dab-remote-cont...
The January 2013 issue of QST discusses the ezcap USB dongle on pages 30 to 35 in an article /Cheap and Easy SDR. /In addition, more information is at
http://rtlsdr.org/ http://osmocom.rtlsdr.org/
At the Sunday Seminar of the 2012 Digital Communications Conference, a custom Ubuntu Linux DVD-ROM with GNU Radio pre-installed on it was distributed
http://dl.dropbox.com/u/17338050/xubuntu-gnuradio.iso http://dl.dropbox.com/u/17338050/xubuntu-gnuradio.jpeg
The GNU Radio home page is at
http://gnuradio.org/redmine/projects/gnuradio/wiki
A .grc file defines a GNU Radio configuration. .grc files for narrow band FM and for wide band FM are at
http://dl.dropbox.com/u/17338050/mono-nbfm-ctcss.grc http://dl.dropbox.com/u/17338050/mono-fm-and-sca.grc
These can be used to listen the weather radio or to an FM repeater and an FM broadcast station, respectively. We need to thank my SDR and DSP guru Chris, KB3CS for providing these .grc files.
After you have booted the DVD-ROM, copy these .grc files to your desktop. Then, double click on a .grc file and gnuradio-companion should start up with a dataflow diagram. Click on the gray gears icon to execute the .grc file; be sure to increase the audio volume as necessary. I will remove these files in two weeks to free up space in my Dropbox.
For those who have a Hermes SDR, Tom McDermott, N5EG has been working with GNU Radio for the Hermes SDR transceiver
http://svn.tapr.org/repos_sdr_hpsdr/trunk/N5EG/
I have not tried this yet, so I cannot comment on this.
Enjoy, David, W2LNX