This report describes the MIT Lincoln Laboratory Transportable Measurements Facility (TMF), a special purpose beacon interrogator patterned after the Discrete Address Beacon Sensor. This van-mounted experimental beacon system includes all ATCRBS/DABS reply processing and monopulse processing, but not other DABS processing. It was developed to collect data at various locations in the United States so that candidate DABS sensor antenna and processing could be evaluated in a real environment. The TMF has been installed and operated at: Logan Airport (Boston), Deer Island, MA (near Logan), Washington National Airport (DCA), Philadelphia Int. Airport (PHL), Clementon, NJ (near Philadelphia), Los Angeles Int. Airport (LAX), Brea, CA (25 miles east of LAX), Salt Lake City, UT (SLC), Layton, UT (near Salt Lake City), Las Vegas Airport (LAS), and Green Airport (Warwick, RI).