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]