Hi Joe

Great, sounds like you should be all set.  The 'source' command might not produce any output (no news is good news in this case).   You probably won't be able to do much though without SDR hardware such as a USRP.  However you should be able to run GRC which enables you to create flowgraphs for simulation and analysis purposes...  If you have any disctap'ed receivers you could use them with OP25, (although you should not expect LSM quality reception)

Max