§ 74.705   TV broadcast analog station protection.

   (a) The TV broadcast station protected contour will be its Grade B
   contour signal level as defined in § 73.683 and calculated from the
   authorized maximum radiated power (without depression angle
   correction), the horizontal radiation pattern, height above average
   terrain in the pertinent direction, and the appropriate chart from
   § 73.699.

   (b)(1) An application to construct a new low power TV or TV translator
   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 TV broadast 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 or TV translator construction permit application
   will not be accepted if it specifies a site within the UHF TV broadcast
   station's protected contour and proposes operation on a channel either
   14 or 15 channels above the channel in use by the TV broadcast station.

   (4) A UHF low power TV or TV translator construction permit application
   will not be accepted if it specifies a site less than 100 kilometers
   from the transmitter site of a UHF TV broadcast analog station
   operating on a channel which is the seventh channel above the requested
   channel, unless it can demonstrate that the service area of the low
   power TV or TV translator station as established in § 74.707(a) is not
   located in an area where the TV broadcast analog station is regularly
   viewed.

   (5) An application for a new UHF low power TV or TV translator
   construction permit, a change of channel, or a major change in
   facilities pursuant to § 73.3572 of this chapter proposing a maximum
   effective radiated power of more than 50 kilowatts will not be accepted
   if it specifies a site less than 32 kilometers from the transmitter
   site of a UHF TV broadcast analog station operating on a channel which
   is the second, third, or fourth channel above or below the requested
   channel.

   (c) The low power TV, TV translator, or TV booster station field
   strength is calculated from the proposed effective radiated power (ERP)
   and the antenna height 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, and TV boosters that do not
   specify the same channel as the TV broadcast 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 TV broadcast station at the 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, 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 will be maintained within the
   tolerances specified in § 74.761 for offset operation.

   (2) 6 dB when the protected TV broadcast station operates on a VHF
   channel that is one channel above the requested channel.

   (3) 12 dB when the protected TV broadcast station operates on a VHF
   channel that is one channel below the requested channel.

   (4) 15 dB when the protected TV broadcast station operates on a UHF
   channel that is one channel above or below the requested channel.

   (5) 23 dB when the protected TV broadcast station operates on a UHF
   channel that is fourteen channels below the requested channel.

   (6) 6 dB when the protected TV broadcast station operates a UHF channel
   that is fifteen channels below the requested channel.

   (e) As an alternative to the preceding paragraphs of 74.705, an
   applicant for a low power TV, TV translator or TV booster 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 TV broadcast 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, 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 21497 , May 18, 1982, as amended at  48 FR 21487 , May 12, 1983;  52 FR 31403 , Aug. 20, 1987;  62 FR 26721 , May 14, 1997;  65 FR 58467 , Sept.
   29, 2000;  69 FR 69332 , Nov. 29, 2004]

   return arrow Back to Top