§ 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, Room CY-C203, 445 12th Street,
   SW., Reference Information Center, Washington, DC 20554. 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]

   return arrow Back to Top