47 C.F.R. § 73.6006 Channel assignments.
Title 47 - Telecommunication
Class A TV stations will not be authorized on UHF TV channels 52 through 69, or on channels unavailable for TV broadcast station use pursuant to §73.603 of this part.
Title 47: Telecommunication
PART 73—RADIO BROADCAST SERVICES
Subpart J—Class A Television Broadcast Stations
§ 73.6006 Channel assignments.

