Title 47
SECTION 74.707
74.707 Low power TV and TV translator station protection.
§ 74.707 Low power TV and TV translator station protection.(a)(1) A low power TV or TV translator will be protected from interference from other low power TV or TV translator stations, or TV booster stations within the following predicted contours:
(i) 62 dBu for stations on Channels 2 through 6;
(ii) 68 dBu for stations on Channels 7 through 13; and
(iii) 74 dBu for stations on Channels 14 through 69.
Existing licensees and permittees that did not furnish sufficient data required to calculate the above contours by April 15, 1983 are assigned protected contours having the following radii: Up to 0.001 kW VHF/UHF - 1 mile (1.6 km) from transmitter site Up to 0.01 kW VHF; up to 0.1 k/W UHF - 2 miles (3.2 km) from transmitter site Up to 0.1 kW VHF; up to 1 kW UHF - 4 miles (6.4 km) from transmitter site New applicants must submit the required information; they cannot rely on this table.(2) The low power TV or TV translator station protected contour is calculated from the authorized effective radiated power and antenna height above average terrain, using Figure 9, 10, or 10b of § 73.699 (F(50,50) charts) of Part 73 of this chapter.
(b)(1) An application to construct a new low power TV, TV translator, or TV booster station or change the facilities of an existing station will not be accepted if it specifies a site which is within the protected contour of a co-channel or first adjacent channel low power TV, TV translator, or TV booster station, except that a TV booster station may be located within the protected contour of its co-channel primary station.
(2) Due to the frequency spacing which exists between TV Channels 4 and 5, between Channels 6 and 7, and between Channels 13 and 14, adjacent channel protection standards shall not be applicable to these pairs of channels. (See § 73.603(a) of Part 73 of this chapter.)
(3) A UHF low power TV, TV translator, or TV booster construction permit application will not be accepted if it specifies a site within the UHF low power TV, TV translator, or TV booster station's protected contour and proposes operation on a channel that is 15 channels above the channel in use by the low power TV, TV translator, or TV booster station.
(c) The low power TV, TV translator, or TV booster construction permit application field strength is calculated from the proposed effective radiated power (ERP) and the antenna above average terrain (HAAT) in pertinent directions.
(1) For co-channel protection, the field strength is calculated using Figure 9a, 10a, or 10c of § 73.699 (F(50,10) charts) of Part 73 of this chapter.
(2) For low power TV, TV translator, or TV booster applications that do not specify the same channel as the low power TV, TV translator, or TV booster station to be protected, the field strength is calculated using Figure 9, 10, or 10b of § 73.699 (F(50,50) charts) of Part 73 of this chapter.
(d) A low power TV, TV translator, or TV booster station application will not be accepted if the ratio in dB of its field strength to that of the authorized low power TV, TV translator, or TV booster station at its protected contour fails to meet the following:
(1) −45 dB for co-channel operations without offset carrier frequency operation or −28 dB for offset carrier frequency operation. An application requesting offset carrier frequency operation must include the following:
(i) A requested offset designation (zero, plus, or minus) identifying the proposed direction of the 10 kHz offset from the standard carrier frequencies of the requested channel. If the offset designation is not different from that of the station being protected, or if the station being protected is not maintaining its frequencies within the tolerance specified in § 74.761 for offset operation, the −45 dB ratio must be used.
(ii) A description of the means by which the low power TV, TV translator, or TV booster station's frequencies will be maintained within the tolerances specified in § 74.761 for offset operation.
(2) 6 dB when the protected low power TV or TV translator station operates on a VHF channel that is one channel above the requested channel.
(3) 12 dB when the protected low power TV or TV translator station operates on a VHF channel that is one channel below the requested channel.
(4) 15 dB when the protected low power TV or TV translator station operates on a UHF channel that is one channel above or below the requested channel.
(5) 6 dB when the protected low power TV or TV translator station operates on a UHF channel that is fifteen channels below the requested channel.
(e) As an alternative to the preceding paragraphs of § 74.707, an applicant for a low power TV or TV translator station may make full use of terrain shielding and Longley-Rice terrain dependent propagation prediction methods to demonstrate that the proposed facility would not be likely to cause interference to low power TV, TV translator and TV booster stations. Guidance on using the Longley-Rice methodology is provided in OET Bulletin No. 69 (but also see § 74.793(d)). Copies of OET Bulletin No. 69 may be inspected during normal business hours at the Federal Communications Commission's Reference Information Center, located at the address of the FCC's main office indicated in 47 CFR 0.401(a). This document is also available through the Internet on the FCC Home Page at http://www.fcc.gov.
[47 FR 21498, May 18, 1982, as amended at 47 FR 35990, Aug. 18, 1982; 48 FR 21487, May 12, 1983; 52 FR 31403, Aug. 20, 1987; 62 FR 26722, May 14, 1997; 65 FR 58467, Sept. 29, 2000; 69 FR 69332, Nov. 29, 2004; 85 FR 64409, Oct. 13, 2020]