radio fox hunt
n.— «This was a radio fox hunt, an event put on by the South East Metro Amateur Radio Club. Radio fox hunting—also known as transmitter hunting, T-hunting, bunny hunting or amateur radio direction finding—is a competition in which ham radio operators armed with directional antennas race across the countryside trying to be the first to find a concealed transmitter.» —“Strong Signals” by Richard Chin Pioneer Press (St. Paul, Minnesota) June 18, 2006. (source: Double-Tongued Dictionary)