If you're using a sensitive digital tuner in Philly and key in 7.1, wouldn't you wind up with WABC-TV?
It's the only nearby 7.1 (and also happens to remain on physical Channel 7, 174 to 180 mHz, sending a full power 123 kW signal from the Empire State Building). Even at a distance, a signal from that high an elevation (over a quarter mile HAAT) is going to clobber anything within 100 miles.