Rochester NY has WXXI for a PBS station on channel 21. It is also curiously reused as the call sign on local AM and FM NPR radio stations. For whatever reason that is allowed.
The FCC generally allows stations that share ownership to use the same callsign for TV, FM, and AM. Not always in the same area either; KCBS-AM is in San Francisco, while KCBS-FM and KCBS-TV are in Los Angeles. Additionally, stations are allowed to keep their call sign when ownership changes, so even though KCBS-FM and AM are no longer owned by the owners of KCBS-FM, they have chosen to keep the same call signs.
Bangor, ME has an ABC affiliate WVII broadcasting on VHF channel 7.