Sec.  73.318   FM blanketing interference.

   Areas adjacent to the transmitting antenna that receive a signal with a
   strength of 115 dBu (562 mV/m) or greater will be assumed to be blanketed.
   In determining the blanketed area, the 115 dBu contour is determined by
   calculating the inverse distance field using the effective radiated power of
   the maximum radiated lobe of the antenna without considering its vertical
   radiation pattern or height. For directional antennas, the effective
   radiated power in the pertinent bearing shall be used.

   (a) The distance to the 115 dBu contour is determined using the following
   equation:

   D (in kilometers)=0.394√ P

   D (in miles)=0.245√ P

   Where P is the maximum effective radiated power (ERP), measured in
   kilowatts, of the maximum radiated lobe.

   (b) After January 1, 1985, permittees or licensees who either (1) commence
   program tests, or (2) replace their antennas, or (3) request facilities
   modifications and are issued a new construction permit must satisfy all
   complaints of blanketing interference which are received by the station
   during a one year period. The period begins with the commencement of program
   tests, or commencement of programming utilizing the new antenna. Resolution
   of complaints shall be at no cost to the complainant. These requirements
   specifically do not include interference complaints resulting from
   malfunctioning or mistuned receivers, improperly installed antenna systems,
   or the use of high gain antennas or antenna booster amplifiers. Mobile
   receivers and non-RF devices such as tape recorders or hi-fi amplifiers
   (phonographs) are also excluded.

   (c) A permittee collocating with one or more existing stations and beginning
   program tests on or after January 1, 1985, must assume full financial
   responsibility for remedying new complaints of blanketing interference for a
   period of one year. Two or more permittees that concurrently collocate on or
   after January 1, 1985, shall assume shared responsibility for remedying
   blanketing complaints within the blanketing area unless an offending station
   can be readily determined and then that station shall assume full financial
   responsibility.

   (d) Following the one year period of full financial obligation to satisfy
   blanketing complaints, licensees shall provide technical information or
   assistance to complainants on remedies for blanketing interference.

   [ 28 FR 13623 , Dec. 14, 1963, as amended at  52 FR 25866 , July 9, 1987]