403-381-7080 gary@drhd.com
RTL-SDR is an inexpensive USB dongle that can be used as a computer based radio scanner for receiving radio signals in your area.  The affordability ($25) of the dongle has allowed even hobbyists on a budget to access the radio spectrum.  There is a ton of information about its capabilities and how it works on the website, so spend some time researching to see if this is right for you.