I want to take this opportunity to clarify something.
Radio scanning-type spirit boxes do NOT produce evidence by spirits picking pieces of words from broadcasts.
The radio broadcasts themselves are not even required. A quiet radio band will produce evidence even better than a crowded one. The best, clearest spirit box evidence, for us, has typically come from inside buildings or basements that effectively shield the device from receiving any human broadcasts.
All the spirits need is a working radio. The sweep function is just a tool to help separate real evidence from human words and music.