Do you know much about the constructions of the building? Is it concrete and steel? The street view in Google Earth looks like that's the case. This is a six story building?
Are you on the Arts Plaza end of the building or the Routh St. end? Do you have a window or other opening that looks out onto Ross Ave. or Routh St.?
When you tried the high-tech (
) paper clip antenna, did you rescan for channels?