47 C.F.R. § 73.683 Field strength contours and presumptive determination of field strength at individual locations.
Title 47 - Telecommunication
(a) In the authorization of TV stations, two field strength contours are considered. These are specified as Grade A and Grade B and indicate the approximate extent of coverage over average terrain in the absence of interference from other television stations. Under actual conditions, the true coverage may vary greatly from these estimates because the terrain over any specific path is expected to be different from the average terrain on which the field strength charts were based. The required field strength, F (50,50), in dB above one micro-volt per meter (dBu) for the Grade A and Grade B contours are as follows: (b) It should be realized that the F (50,50) curves when used for Channels 14–69 are not based on measured data at distances beyond about 48.3 kilometers (30 miles). Theory would indicate that the field strengths for Channels 14–69 should decrease more rapidly with distance beyond the horizon than for Channels 2–6, and modification of the curves for Channels 14–69 may be expected as a result of measurements to be made at a later date. For these reasons, the curves should be used with appreciation of their limitations in estimating levels of field strength. Further, the actual extent of service will usually be less than indicated by these estimates due to interference from other stations. Because of these factors, the predicted field strength contours give no assurance of service to any specific percentage of receiver locations within the distances indicated. In licensing proceedings these variations will not be considered. (c) The field strength contours will be considered for the following purposes only: (1) In the estimation of coverage resulting from the selection of a particular transmitter site by an applicant for a TV station. (2) In connection with problems of coverage arising out of application of §73.3555. (3) In determining compliance with §73.685(a) concerning the minimum field strength to be provided over the principal community to be served. (d) For purposes of determining the eligibility of individual households for satellite retransmission of distant network signals under the copyright law provisions of 17 U.S.C. 119(d)(10)(A), field strength shall be determined by the Individual Location Longley-Rice (ILLR) propagation prediction model. Guidance for use of the ILLR model for these purposes is provided in OET Bulletin No. 72. This document is available through the Internet on the FCC Home Page at http://www.fcc.gov. (e) In the case of measurements to determine the eligibility of individual households to receive satellite retransmission of distant network signals under the copyright law provisions of 17 U.S.C. 119(d)(10), if a satellite carrier and the network station or stations asserting that the retransmission of a signal of a distant network station is prohibited are unable to agree on a person to conduct the test, the American Radio Relay League, Inc., 225 Main Street, Newington, CT 06111–1494, shall designate the person or organization to conduct measurements based on the technical qualifications and independence of proposed testers. The satellite carrier and network station shall propose testers and provide their qualifications in writing to the American Radio Relay League (ARRL). Individuals may also volunteer themselves as testers by submitting their qualifications to the ARRL. The ARRL can be reached by telephone at 860–594–0200, or email at [email protected]. (f) A satellite carrier is exempt from the verification requirements of 47 U.S.C. 339(c)(4)(A) with respect to a test requested by a satellite subscriber to whom the retransmission of the signals of local broadcast stations is available under 47 U.S.C. 338 from such carrier. The definitions of satellite carrier, subscriber, and local market contained in 47 CFR 76.66(a) apply to this paragraph (f). [44 FR 36039, June 20, 1979, as amended at 47 FR 35990, Aug. 18, 1982; 50 FR 23699, June 5, 1985; 50 FR 32416, Aug. 12, 1985; 65 FR 36641, June 9, 2000; 70 FR 21670, Apr. 27, 2005]
Title 47: Telecommunication
PART 73—RADIO BROADCAST SERVICES
Subpart E—Television Broadcast Stations
§ 73.683 Field strength contours and presumptive determination of field strength at individual locations.
------------------------------------------------------------------------ Grade A Grade B (dBu) (dBu)------------------------------------------------------------------------Channels 2-6.................................... 68 47Channels 7-13................................... 71 56Channels 14-69.................................. 74 64------------------------------------------------------------------------
