What scanner are you using? Some scanners do not follow patches properly so if B7 is patched to B2 and B2 is the primary TG in the patch, your scanner may not ever see B7 as active. Listen for the other Troop B TGs and see if you hear any relevant traffic on those and that may answer your question. As others have said, Robeson isn't super busy either so depending on who is working where in the county, you may not have any affiliations pulling traffic to the tower you're monitoring.