I rescan at least once a month with both the converter boxes and my HDTV. It was hooked up to the same wiring and rooftop antenna. My older sets are on rabbit ears is why I thought every thing was the same. With the converter box on rabbit ears I get the same 6 stations as the HD set. this is the first time I tried the converter box on the rooftop antenna. With my HD set tuner I get dayton ohio locals only-with the converter box I get dayton, cincinnati and two columbus stations. And there not weak signals or boderline pickups. The signals from cincy (50 miles away) are around 55-60. Of course The converter is only 480i so I still want HD.