47 CFR 87.451 - Licensing limitations.
Operational fixed stations are subject to the following licensing limitations:
(a) A maximum of four frequencies will be assigned.
(b) Stations will not be authorized when applications indicate less than 16 km (10 miles) separation between a proposed station and a TV transmitter operating on either Channel 4 or 5, or from the post office of a community in which either channel is assigned but not in operation.
(c) Stations located between 16 km (10 miles) and 128 km (80 miles) of a TV transmitter operating on either Channel 4 or 5, or from the post office of a community in which either channel is assigned but not in operation, are secondary to TV operations within the Grade B service contour. 1
1 OET Bulletin No. 67, March 1988, entitled “Potential Interference from Operational Fixed Stations in the 72-76 MHz Band to Television Channels 4 and 5” describes an analytical model that can be used to calculate the potential interference that might result from a given fixed station operation. Copies of the bulletin may be obtained from the Commission's current duplication contractor. Information concerning the current duplication contractor may be obtained from the Office of Public Affairs, Consumer Assistance and Small Business Division, Telephone (202) 632-5050.