Section 73.617 - Interference protection of other services(a)Protection of land mobile operations on channels 14-20. The Commission will not accept petitions to amend the Table of TV Allotments, applications for new TV stations, or applications to change the channel or location of authorized TV stations that would use channels 14-20 where the distance between the TV reference coordinates as defined in § 73.622(d) , would be located less than 250 km from the city center of a co-channel land mobile operation or 176 km from the city center of an adjacent channel land mobile operation. Such filings that do not meet the minimum TV-to-land mobile spacing standards will, however, be considered where all affected land mobile licensees consent to the requested action. Land mobile operations are authorized on these channels in the following markets: Table 1 to Paragraph (a)-Land Mobile Operations To Be Protected
| City | Channels | Latitude | Longitude |
| Boston, MA | 14, 16 | 42°21'24.4" | 71°03'23.2" |
| Chicago, IL | 14, 15 | 41°52'28.1" | 87°38'22.2" |
| Cleveland, OH | 14, 15 | 41°29'51.2" | 81°49'49.5" |
| Dallas, TX | 16 | 32°47'09.5" | 96°47'38.0" |
| Detroit, MI | 15, 16 | 42°19'48.1" | 83°02'56.7" |
| Houston, TX | 17 | 29°45'26.8" | 95°21'37.8" |
| Los Angeles, CA | 14, 16, 20 | 34°03'15.0" | 118°14'31.3" |
| Miami, FL | 14 | 25°46'38.4" | 80°11'31.2" |
| New York, NY | 14, 15, 16 | 40°45'06.4" | 73°59'37.5" |
| Philadelphia, PA | 19, 20 | 39°56'58.4" | 75°09'19.6" |
| Pittsburgh, PA | 14, 18 | 40°26'19.2" | 79°59'59.2" |
| San Francisco, CA | 16, 17 | 37°46'38.7" | 122°24'43.9" |
| Washington, DC | 17, 18 | 38°53'51.4" | 77°00'31.9" |
Note 1 to paragraph (a). The Chief, Public Safety and Homeland Security Bureau, waived the rules to allow channel 15 to be used for land mobile operation in Los Angeles County, CA (DA 08-2823; adopted December 30, 2008). Notwithstanding the channels listed in paragraph (a) of this section, the waiver requires television stations to protect this land mobile operation.
(b)Protection of land mobile operations below channel 14.(1) TV broadcast stations operating on Channel 14 must take special precautions to avoid interference to adjacent spectrum land mobile radio service facilities. Where a TV station is authorized and operating prior to the authorization and operation of the land mobile facility, a Channel 14 station must attenuate its emissions within the frequency range 467 to 470 MHz if necessary to permit reasonable use of the adjacent frequencies by land mobile licensees.(2) The requirements listed below apply to permittees authorized to construct a new station on TV Channel 14, and to licensees authorized to change the channel of an existing station to Channel 14, to increase effective radiated power (ERP) (including any change in directional antenna characteristics that results in an increase in ERP in any direction), or to change the transmitting location of an existing station. (i) For the purposes of this paragraph (b), a protected land mobile facility is a receiver that is intended to receive transmissions from licensed land mobile stations within the frequency band below 470 MHz, and is associated with one or more land mobile stations for which a license has been issued by the Commission, or a proper application has been received by the Commission prior to the date of the filing of the TV construction permit application. However, a land mobile facility will not be protected if it is proposed in an application that is denied or dismissed and that action is no longer subject to Commission review. Further, if the land mobile station is not operating when the TV facility commences operation and it does not commence operation within the time permitted by its authorization in accordance with part 90 of this chapter, it will not be protected.(ii) A TV permittee must take steps before construction to identify potential interference to normal land mobile operation that could be caused by TV emissions outside the authorized channel, land mobile receiver desensitization or intermodulation. It must install filters and take other precautions as necessary, and submit evidence that no interference is being caused before it will be permitted to transmit programming on the new facilities pursuant to the provisions of § 73.1615 or § 73.1620 . A TV permittee must reduce its emissions within the land mobile channel of a protected land mobile facility that is receiving interference caused by the TV emission producing a vertically polarized signal and a field strength in excess of 17 dBu at the land mobile receiver site on the land mobile frequency. The TV emission should be measured with equipment set to a 30 kHz measurement bandwidth including the entire applicable land mobile channel. A TV permittee must correct a desensitization problem if its occurrence can be directly linked to the start of the TV operation and the land mobile station is using facilities with typical desensitization rejection characteristics. A TV permittee must identify the source of an intermodulation product that is generated when the TV operation commences. If the intermodulation source is under its control, the TV permittee must correct the problem. If the intermodulation source is beyond the TV permittee's control, it must cooperate in the resolution of the problem and should provide whatever technical assistance it can.(c)Channel 6 protection of FM radio stations. Parties requesting new allotments on channel 6 be added to the Table of TV Allotments must submit an engineering study demonstrating that no interference would be caused to existing FM radio stations on FM channels 200-220.(d)Blanketing interference. Present information is not sufficiently complete to establish blanketing interference areas for television broadcast stations. Blanketing interference is interference in an area adjacent to a transmitter in which the reception of other stations is subject to interference due to the strong signal from this station. The authorization of station construction in areas where blanketing interference is found to be excessive will be on the basis that the applicant will assume full responsibility for the adjustment of reasonable complaints arising from excessively strong signals of the applicant's station or take other corrective action.(e)Medical telemetry device notification condition. Stations should be aware that a condition is placed on all TV broadcast station authorizations that result in a change in coverage area, including all authorizations for new stations, which requires TV broadcasters to identify and notify hospital and other health care facilities within the station's coverage area to avoid interference to medical telemetry devices. 89 FR 7245 , Feb. 1, 2024