[Code of Federal Regulations]
[Title 47, Volume 4]
[Revised as of October 1, 2001]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR73.683]

[Page 222-223]
 
                       TITLE 47--TELECOMMUNICATION
 
                    CHAPTER I--FEDERAL COMMUNICATIONS
                         COMMISSION (Continued)
 
PART 73--RADIO BROADCAST SERVICES--Table of Contents
 
                Subpart E--Television Broadcast Stations
 
Sec. 73.683  Field strength contours and presumptive determination of field strength at individual locations.

    (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:

------------------------------------------------------------------------
                                                    Grade A     Grade B
                                                     (dBu)       (dBu)
------------------------------------------------------------------------
Channels 2-6....................................          68          47
Channels 7-13...................................          71          56
Channels 14-69..................................          74          64
------------------------------------------------------------------------

    (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

[[Page 223]]

(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 Sec. 73.3555.
    (3) In determining compliance with Sec. 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 
hq@arrl.org.

[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]