(a) An application for a new TV broadcast station or for changes in the operating facilities of an existing TV broadcast station will not be accepted for filing if it fails to comply with the requirements specified in this section.

(b) Due to the frequency spacing which exists between TV channels 4 and 5, between channels 6 and 7, and between channels 13 and 14, first-adjacent channel protection standards shall not be applicable to these pairs of channels. Some interference protection requirements of this section only apply to stations transmitting on the UHF TV channels 14 through 51 (See §73.603(a) of this part).

(c) A UHF TV broadcast station application will not be accepted if it specifies a site less than 100 kilometers from the transmitter site of a UHF Class A TV station operating on a channel which is the seventh channel above the requested channel. Compliance with this requirement shall be determined based on a distance computation rounded to the nearest kilometer.

(d) A UHF TV broadcast station application will not be accepted if it specifies a site less than 32 kilometers from the transmitter site of a UHF Class A TV station that is authorized an effective radiated power of more than 50 kilowatts and operating on a channel which is the second, third, or fourth channel above or below the requested channel. Compliance with this requirement shall be determined based on a distance computation rounded to the nearest kilometer.

(e) In cases where a TV broadcast station has been authorized facilities that do not meet the distance separation requirements of this section, an application to modify such a station's facilities will not be accepted if it decreases that separation.

(f) New interference must not be caused to Class A TV stations authorized pursuant to Subpart J of this part, within the protected contour defined in §73.6010 of this part. For this prediction, the TV broadcast station field strength is calculated from the proposed effective radiated power and the antenna height above average terrain in pertinent directions using the methods in §73.684 of this part.

(1) For co-channel protection, the field strength is calculated using the appropriate F(50,10) chart from Figure 9a, 10a, or 10c of §73.699 of this part.

(2) For TV broadcast stations that do not specify the same channel as the Class A TV station to be protected, the field strength is calculated using the appropriate F(50,50) chart from Figure 9, 10, or 10b of §73.699 of this part.

(g) A TV broadcast station application will not be accepted if the ratio in dB of its field strength to that of the Class A TV station at the Class A TV station's protected contour fails to meet the following:

(1) −45 dB for co-channel operations where the Class A TV station does not specify an offset carrier frequency or where the TV broadcast and Class A TV stations do not specify different offset carrier frequencies (zero, plus or minus) or −28 dB for offset carrier frequency operation where the TV broadcast and Class A TV stations specify different offset carrier frequencies.

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

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

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

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

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

(h) New interference must not be caused to digital Class A TV stations authorized pursuant to Subpart J of this part, within the protected contour defined in §73.6010 of this part. A TV broadcast station application will not be accepted if the ratio in dB of the field strength of the digital Class A TV station at the digital Class A TV station's protected contour to the field strength resulting from the facilities proposed in the TV broadcast station application fails to meet the D/U signal ratios for “analog TV-into-DTV” specified in §§73.623(c)(2) and 73.623(c)(3) of this part. For digital Class A TV station protection, the TV broadcast station field strength is calculated from the proposed effective radiated power and the antenna height above average terrain in pertinent directions using the methods in §73.684 of this part and using the appropriate F(50,10) chart from Figure 9a, 10a, or 10c of §73.699 of this part.

(i) In cases where a TV broadcast station has been authorized facilities that do not meet the interference protection requirements of this section, an application to modify such a station's facilities will not be accepted if it is predicted to cause new interference within the protected contour of the Class A TV or digital Class A TV station.

(j) In support of a request for waiver of the interference protection requirements of this section, an applicant for a TV broadcast station may make full use of terrain shielding and Longley-Rice terrain dependent propagation methods to demonstrate that the proposed facility would not be likely to cause interference to Class A TV stations. Guidance on using the Longely-Rice methodology is provided in OET Bulletin No. 69, which is available through the Internet at http://www.fcc.gov/oet/info/documents/bulletins/#69.

[65 FR 3001, May 10, 2000]