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to the input signals of FM translator or FM booster stations 73 840 Operating power and mode tolerances 73 845 Transmission system operation 73 850 Operating schedule 73 853 Licensing requirements and service 73 854 Unlicensed radio operations 73 855 Ownership limits 73 858 Attribution of LPFM station interests 73 860 Cross ownership 73 865 Assignment and transfer of LPFM permits and licenses 73 870 Processing of LPFM broadcast station applications 73 871 Amendment of LPFM broadcast station applications 73 872 Selection procedure for mutually exclusive LPFM applications 73 873 LPFM license period 73 875 Modification of transmission systems 73 877 Station logs for LPFM stations 73 878 Station inspections by FCC availability to FCC of station logs and records 73 879 Signal retransmission 73 881 Equal employment opportunities Subpart H Rules Applicable to All Broadcast Stations 73 1001 Scope 47 CFR Part 73 Feb 20 2024 enhanced display page 6 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR Part 73 Feb 20 2024 Radio Broadcast Services 73 1010 Cross reference to rules in other parts 73 1015 Truthful written statements and responses to Commission inquiries and correspondence 73 1020 Station license period 73 1030 Notifications concerning interference to radio astronomy research and receiving installations 73 1120 Station location 73 1125 Station telephone number 73 1150 Transferring a station 73 1201 Station identification 73 1202 Reserved 73 1206 Broadcast of telephone conversations 73 1207 Rebroadcasts 73 1208 Broadcast of taped filmed or recorded material 73 1209 References to time 73 1210 TV FM dual language broadcasting in Puerto Rico 73 1211 Broadcast of lottery information 73 1212 Sponsorship identification list retention related requirements 73 1213 Antenna structure marking and lighting 73 1215 Specifications for indicating instruments 73 1216 Licensee conducted contests 73 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
1217 Broadcast hoaxes 73 1225 Station inspections by FCC 73 1226 Availability to FCC of station logs and records 73 1250 Broadcasting emergency information 73 1300 Unattended station operation 73 1350 Transmission system operation 73 1400 Transmission system monitoring and control 73 1515 Special field test authorizations 73 1520 Operation for tests and maintenance 73 1530 Portable test stations Definition 73 1540 Carrier frequency measurements 73 1545 Carrier frequency departure tolerances 73 1560 Operating power and mode tolerances 73 1570 Modulation levels AM FM TV and Class A TV aural 73 1580 Transmission system inspections 73 1590 Equipment performance measurements 73 1610 Equipment tests 73 1615 Operation during modification of facilities 47 CFR Part 73 Feb 20 2024 enhanced display page 7 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR Part 73 Feb 20 2024 Radio Broadcast Services 73 1620 Program tests 73 1635 Special temporary authorizations STA 73 1650 International agreements 73 1660 Acceptability of broadcast transmitters 73 1665 Main transmitters 73 1670 Auxiliary transmitters 73 1675 Auxiliary antennas 73 1680 Emergency antennas 73 1690 Modification of transmission systems 73 1692 Reserved 73 1695 Changes in transmission standards 73 1700 Broadcast day 73 1705 Time of operation 73 1710 Unlimited time 73 1715 Share time 73 1720 Daytime 73 1725 Limited time 73 1730 Specified hours 73 1735 AM station operation pre sunrise and post sunset 73 1740 Minimum operating schedule 73 1745 Unauthorized operation 73 1750 Discontinuance of operation 73 1800 General requirements related to the station log 73 1820 Station log 73 1835 Special technical records 73 1840 Retention of logs 73 1870 Chief operators 73 1940 Legally qualified candidates for public office 73 1941 Equal opportunities 73 1942 Candidate rates 73 1943 Political file 73 1944 Reasonable access | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
73 2080 Equal employment opportunities EEO 73 2090 Ban on discrimination in broadcast transactions 73 3500 Application and report forms 73 3511 Applications required 73 3512 Where to file number of copies 73 3513 Signing of applications 73 3514 Content of applications 47 CFR Part 73 Feb 20 2024 enhanced display page 8 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR Part 73 Feb 20 2024 Radio Broadcast Services 73 3516 Specification of facilities 73 3517 Contingent applications 73 3518 Inconsistent or conflicting applications 73 3519 Repetitious applications 73 3520 Multiple applications 73 3521 Mutually exclusive applications for low power television television translators and television booster stations 73 3522 Amendment of applications 73 3523 Dismissal of applications in renewal proceedings 73 3525 Agreements for removing application conflicts 73 3526 Online public inspection file of commercial stations 73 3527 Online public inspection file of noncommercial educational stations 73 3533 Application for construction permit or modification of construction permit 73 3534 Reserved 73 3536 Application for license to cover construction permit 73 3537 Application for license to use former main antenna as an auxiliary 73 3538 Application to make changes in an existing station 73 3539 Application for renewal of license 73 3540 Application for voluntary assignment or transfer of control 73 3541 Application for involuntary assignment of license or transfer of control 73 3542 Application for emergency authorization 73 3543 Application for renewal or modification of special service authorization 73 3544 Application to obtain a modified station license 73 3545 Application for permit to deliver programs to foreign stations 73 3549 Requests for extension of time to operate without required monitors indicating instruments and EAS encoders and decoders 73 3550 Requests for new or modified call sign assignments 73 3555 Multiple ownership 73 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
3561 Staff consideration of applications requiring Commission action 73 3562 Staff consideration of applications not requiring action by the Commission 73 3564 Acceptance of applications 73 3566 Defective applications 73 3568 Dismissal of applications 73 3571 Processing of AM broadcast station applications 73 3572 Processing of TV broadcast Class A TV broadcast low power TV TV translators and TV booster applications 73 3573 Processing FM broadcast station applications 73 3574 Processing of international broadcast station applications 73 3578 Amendments to applications for renewal assignment or transfer of control 47 CFR Part 73 Feb 20 2024 enhanced display page 9 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR Part 73 Feb 20 2024 Radio Broadcast Services 73 3580 Local public notice of filing of broadcast applications 73 3584 Procedure for filing petitions to deny 73 3587 Procedure for filing informal objections 73 3588 Dismissal of petitions to deny or withdrawal of informal objections 73 3589 Threats to file petitions to deny or informal objections 73 3591 Grants without hearing 73 3592 Conditional grant 73 3593 Designation for hearing 73 3594 Local public notice of designation for hearing 73 3597 Procedures on transfer and assignment applications 73 3598 Period of construction 73 3601 Simultaneous modification and renewal of license 73 3603 Special waiver procedure relative to applications 73 3605 Retention of applications in hearing status after designation for hearing 73 3612 Annual employment report 73 3613 Availability to FCC of station contracts 73 3615 Ownership reports 73 3617 Information available on the internet 73 3700 Post incentive auction licensing and operation 73 3701 Reimbursement under the Reimbursement Expansion Act 73 3800 Full power television channel sharing outside the incentive auction 73 3801 Full power television simulcasting during the ATSC 3 0 Next Gen TV | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
transition 73 3999 Enforcement of 18 U S C 1464 restrictions on the transmission of obscene and indecent material 73 4000 Listing of FCC policies 73 4005 Advertising refusal to sell 73 4015 Applications for AM and FM construction permits incomplete or defective 73 4017 Application processing Commercial FM stations 73 4045 Barter agreements 73 4050 Children s TV programs 73 4055 Cigarette advertising 73 4060 Citizens agreements 73 4075 Commercials loud 73 4082 Comparative broadcast hearings specialized programming formats 73 4091 Direct broadcast satellites 73 4094 Dolby encoder 73 4095 Drug lyrics 73 4097 EBS now EAS attention signals on automated programing systems 73 4099 Financial qualifications certification of 47 CFR Part 73 Feb 20 2024 enhanced display page 10 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR Part 73 Feb 20 2024 Radio Broadcast Services 73 4100 Financial qualifications new AM and FM stations 73 4101 Financial qualifications TV stations 73 4102 FAA communications broadcast of 73 4104 FM assignment policies and procedures 73 4107 FM broadcast assignments increasing availability of 73 4108 FM transmitter site map submissions 73 4110 Format changes of stations 73 4135 Interference to TV reception by FM stations 73 4140 Minority ownership tax certificates and distress sales 73 4154 Network AM FM station affiliation agreements 73 4157 Network signals which adversely affect affiliate broadcast service 73 4163 Noncommercial nature of educational broadcast stations 73 4165 Obscene language 73 4170 Obscene broadcasts 73 4180 Payment disclosure Payola plugola kickbacks 73 4185 Political broadcasting and telecasting the law of 73 4190 Political candidate authorization notice and sponsorship identification 73 4195 Political advertising by UHF translators 73 4210 Procedure Manual The Public and Broadcasting 73 4215 Program matter Supplier identification 73 4242 Sponsorship identification rules applicability of 73 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
4246 Stereophonic pilot subcarrier use during monophonic programming 73 4247 STV Competing applications 73 4250 Subliminal perception 73 4255 Tax certificates Issuance of 73 4260 Teaser announcements 73 4265 Telephone conversation broadcasts network and like sources 73 4266 Tender offer and proxy statements 73 4267 Time brokerage 73 4275 Tone clusters audio attention getting devices 73 4280 Character evaluation of broadcast applicants Subpart I Procedures for Competitive Bidding and for Applications for Noncommercial Educational Broadcast Stations on Non Reserved Channels 73 5000 Services subject to competitive bidding 73 5001 Reserved 73 5002 Application and certification procedures return of mutually exclusive applications not subject to competitive bidding procedures prohibition of collusion 73 5003 Submission of full payments 47 CFR Part 73 Feb 20 2024 enhanced display page 11 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR Part 73 Feb 20 2024 Radio Broadcast Services 73 5004 Reserved 73 5005 Filing of long form applications 73 5006 Filing of petitions to deny against long form applications 73 5007 Designated entity provisions 73 5008 Definitions applicable for designated entity provisions 73 5009 Assignment or transfer of control Subpart J Class A Television Broadcast Stations 73 6000 Definitions 73 6001 Eligibility and service requirements 73 6002 Licensing requirements 73 6003 73 6005 Reserved 73 6006 Channel assignments 73 6007 Power limitations 73 6008 Distance computations 73 6010 Class A TV station protected contour 73 6012 Protection of Class A TV low power TV and TV translator stations 73 6013 Protection of DTV stations 73 6014 Protection of digital Class A TV stations 73 6017 Digital Class A TV station protection of Class A TV and digital Class A TV stations 73 6018 Digital Class A TV station protection of DTV stations 73 6019 Digital Class A | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
TV station protection of low power TV TV translator digital low power TV and digital TV translator stations 73 6020 Protection of stations in the land mobile radio service 73 6022 Negotiated interference and relocation agreements 73 6023 Distributed transmission systems 73 6024 Transmission standards and system requirements 73 6025 Antenna system and station location 73 6026 Broadcast regulations applicable to Class A television stations 73 6027 Class A TV notifications concerning interference to radio astronomy research and receiving installations 73 6028 Class A television channel sharing outside the incentive auction 73 6029 Class A television simulcasting during the ATSC 3 0 Next Gen TV transition 73 6030 Low Power Protection Act Subpart K Application and Selection Procedures for Reserved Noncommercial Educational Channels and for Certain Applications for Noncommercial Educational Stations on Non Reserved Channels 73 7000 Definition of terms as used in subpart K only 73 7001 Services subject to evaluation by point system 73 7002 Fair distribution of service on reserved band FM channels 47 CFR Part 73 Feb 20 2024 enhanced display page 12 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR Part 73 Feb 20 2024 Radio Broadcast Services 73 7003 Point system selection procedures 73 7004 Petitions to deny tentative selectee s 73 7005 Maintenance of comparative qualifications Subpart L Incorporated Standards 73 8000 Incorporation by reference Alphabetical Index Part 73 PART 73 RADIO BROADCAST SERVICES Authority 47 U S C 154 155 301 303 307 309 310 334 336 339 Subpart A AM Broadcast Stations 73 1 Scope This subpart contains those rules which apply exclusively to the AM broadcast service and are in addition to those rules in Subpart H which are common to all AM FM and TV broadcast services commercial and noncommercial 47 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
FR 8587 Mar 1 1982 73 14 AM broadcast definitions AM broadcast band The band of frequencies extending from 535 to 1705 kHz AM broadcast channel The band of frequencies occupied by the carrier and the upper and lower sidebands of an AM broadcast signal with the carrier frequency at the center Channels are designated by their assigned carrier frequencies The 117 carrier frequencies assigned to AM broadcast stations begin at 540 kHz and progress in 10 kHz steps to 1700 kHz See 73 21 for the classification of AM broadcast channels AM broadcast station A broadcast station licensed for the dissemination of radio communications intended to be received by the public and operated on a channel in the AM broadcast band Amplitude modulated stage The radio frequency stage to which the modulator is coupled and in which the carrier wave is modulated in accordance with the system of amplitude modulation and the characteristics of the modulating wave Amplitude modulator stage The last amplifier stage of the modulating wave amplitude modulates a radio frequency stage Antenna current The radio frequency current in the antenna with no modulation Antenna input power The product of the square of the antenna current and the antenna resistance at the point where the current is measured Antenna resistance The total resistance of the transmitting antenna system at the operating frequency and at the point at which the antenna current is measured 47 CFR 73 14 Antenna resistance enhanced display page 13 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 14 Auxiliary facility Radio Broadcast Services Auxiliary facility An auxiliary facility is an AM antenna tower s separate from the main facility s antenna tower s permanently installed at the same site or at a different location | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
from which an AM station may broadcast for short periods without prior Commission authorization or notice to the Commission while the main facility is not in operation e g where tower work necessitates turning off the main antenna or where lightning has caused damage to the main antenna or transmission system See 73 1675 Blanketing The interference which is caused by the presence of an AM broadcast signal of one volt per meter V m or greater strengths in the area adjacent to the antenna of the transmitting station The 1 V m contour is referred to as the blanket contour and the area within this contour is referred to as the blanket area Carrier amplitude regulation Carrier shift The change in amplitude of the carrier wave in an amplitude modulated transmitter when modulation is applied under conditions of symmetrical modulation Combined audio harmonics The arithmetical sum of the amplitudes of all the separate harmonic components Root sum square harmonic readings may be accepted under conditions prescribed by the FCC Critical hours The two hour period immediately following local sunrise and the two hour period immediately preceding local sunset Daytime The period of time between local sunrise and local sunset Effective field Effective field strength The root mean square RMS value of the inverse distance fields at a distance of 1 kilometer from the antenna in all directions in the horizontal plane The term field strength is synonymous with the term field intensity as contained elsewhere in this Part Equipment performance measurements The measurements performed to determine the overall performance characteristics of a broadcast transmission system from point of program origination to sampling of signal as radiated See 73 1590 Experimental period the time between 12 midnight local time and local sunrise used by AM stations for tests maintenance and | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
experimentation Frequency departure The amount of variation of a carrier frequency or center frequency from its assigned value Incidental phase modulation The peak phase deviation in radians resulting from the process of amplitude modulation Input power Means the product of the direct voltage applied to the last radio stage and the total direct current flowing to the last radio stage measured without modulation Intermittent service area Means the area receiving service from the groundwave of a broadcast station but beyond the primary service area and subject to some interference and fading Last radio stage The radio frequency power amplifier stage which supplies power to the antenna Left or right signal The electrical output of a microphone or combination of microphones placed so as to convey the intensity time and location of sounds originated predominately to the listener s left or right of the center of the performing area Left or right stereophonic channel The left or right signal as electrically reproduced in reception of AM stereophonic broadcasts Main channel The band of audio frequencies from 50 to 10 000 Hz which amplitude modulates the carrier 47 CFR 73 14 Main channel enhanced display page 14 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 14 Maximum percentage of modulation Radio Broadcast Services Maximum percentage of modulation The greatest percentage of modulation that may be obtained by a transmitter without producing in its output harmonics of the modulating frequency in excess of those permitted by these regulations See 73 1570 Maximum rated carrier power The maximum power at which the transmitter can be operated satisfactorily and is determined by the design of the transmitter and the type and number of vacuum tubes or other amplifier devices used in the last radio stage Model | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
I facility A station operating in the 1605 1705 kHz band featuring fulltime operation with stereo competitive technical quality 10 kW daytime power 1 kW nighttime power non directional antenna or a simple directional antenna system and separated by 400 800 km from other co channel stations Model II facility A station operating in the 535 1605 kHz band featuring fulltime operation competitive technical quality wide area daytime coverage with nighttime coverage at least 15 of the daytime coverage Modulation dependent carrier level MDCL control technologies Transmitter control techniques that vary either the carrier power level or both the carrier and sideband power levels as a function of the modulation level Nighttime The period of time between local sunset and local sunrise Nominal power The antenna input power less any power loss through a dissipative network and for directional antennas without consideration of adjustments specified in paragraphs b 1 and b 2 of 73 51 of the rules However for AM broadcast applications granted or filed before June 3 1985 nominal power is specified in a system of classifications which include the following values 50 kW 25 kW 10 kW 5 kW 2 5 kW 1 kW 0 5 kW and 0 25 kW The specified nominal power for any station in this group of stations will be retained until action is taken on or after June 3 1985 which involves a change in the technical facilities of the station Percentage modulation amplitude In a positive direction M MAX C 100 c In a negative direction M C MIN 100 c Where M Modulation level in percent MAX Instantaneous maximum level of the modulated radio frequency envelope 47 CFR 73 14 Percentage modulation amplitude enhanced display page 15 of 580 47 CFR Part 73 up to date as of 2 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
20 2024 47 CFR 73 14 Plate modulation Radio Broadcast Services MIN Instantaneous minimum level of the modulated radio frequency envelope C Carrier level of radio frequency envelope without modulation Plate modulation The modulation produced by introduction of the modulating wave into the plate circuit of any tube in which the carrier frequency wave is present Primary service area Means the service area of a broadcast station in which the groundwave is not subject to objectionable interference or objectionable fading Proof of performance measurements or antenna proof of performance measurements The measurements of field strengths made to determine the radiation pattern or characteristics of an AM directional antenna system Secondary service area Means the service area of a broadcast station served by the skywave and not subject to objectionable interference and in which the signal is subject to intermittent variations in strength Stereophonic channel The band of audio frequencies from 50 to 10 000 Hz containing the stereophonic information which modulates the radio frequency carrier Stereophonic crosstalk An undesired signal occurring in the main channel from modulation of the stereophonic channel or that occurring in the stereophonic channel from modulation of the main channel Stereophonic pilot tone An audio tone of fixed or variable frequency modulating the carrier during the transmission of stereophonic programs Stereophonic separation The ratio of the electrical signal caused in the right or left stereophonic channel to the electrical signal caused in the left or right stereophonic channel by the transmission of only a right or left signal Sunrise and sunset For each particular location and during any particular month the time of sunrise and sunset as specified in the instrument of authorization See 73 1209 White area The area or population which does not receive interference free primary service from an authorized AM station or | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
does not receive a signal strength of at least 1 mV m from an authorized FM station 47 FR 8587 Mar 1 1982 as amended at 47 FR 13164 Mar 29 1982 47 FR 13812 Apr 1 1982 50 FR 18821 May 2 1985 50 FR 47054 Nov 14 1985 56 FR 64856 Dec 12 1991 62 FR 51058 Sept 30 1997 66 FR 20755 Apr 25 2001 81 FR 2759 Jan 19 2016 82 FR 57882 Dec 8 2017 73 21 Classes of AM broadcast channels and stations a Clear channel A clear channel is one on which stations are assigned to serve wide areas These stations are protected from objectionable interference within their primary service areas and depending on the class of station their secondary service areas Stations operating on these channels are classified as follows 1 Class A station A Class A station is an unlimited time station that operates on a clear channel and is designed to render primary and secondary service over an extended area and at relatively long distances from its transmitter Its primary service area is protected from objectionable interference from other stations on the same and adjacent channels and its secondary service area is protected from interference from other stations on the same channel See 73 182 The operating power shall not be less than 10 kW nor more than 50 kW Also see 73 25 a 47 CFR 73 21 a 1 enhanced display page 16 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 21 a 2 Radio Broadcast Services 2 Class B station Class B stations are authorized to operate with a minimum power of 0 25 kW or if less than 0 25 kW an equivalent RMS antenna field of | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
at least 107 5 mV m at 1 kilometer and a maximum power of 50 kW or 10 kW for stations that are authorized to operate in the 1605 1705 kHz band 3 Class D station A Class D station operates either daytime limited time or unlimited time with nighttime power less than 0 25 kW and an equivalent RMS antenna field of less than 107 5 mV m at 1 kilometer Class D stations shall operate with daytime powers not less than 0 25 kW nor more than 50 kW Nighttime operations of Class D stations are not afforded protection and must protect all Class A and Class B operations during nighttime hours New Class D stations that had not been previously licensed as Class B will not be authorized b Regional Channel A regional channel is one on which Class B and Class D stations may operate and serve primarily a principal center of population and the rural area contiguous thereto Note Until the North American Regional Broadcasting Agreement NARBA is terminated with respect to the Bahama Islands and the Dominican Republic radiation toward those countries from a Class B station may not exceed the level that would be produced by an omnidirectional antenna with a transmitted power of 5 kW or such lower level as will comply with NARBA requirements for protection of stations in the Bahama Islands and the Dominican Republic against objectionable interference c Local channel A local channel is one on which stations operate unlimited time and serve primarily a community and the suburban and rural areas immediately contiguous thereto 1 Class C station A Class C station is a station operating on a local channel and is designed to render service only over a primary service area that may be reduced as a | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
consequence of interference in accordance with 73 182 The power shall not be less than 0 25 kW nor more than 1 kW Class C stations that are licensed to operate with 0 1 kW may continue to do so 56 FR 64856 Dec 12 1991 as amended at 81 FR 2759 Jan 19 2016 73 23 AM broadcast station applications affected by international agreements a Except as provided in paragraph b of this section no application for an AM station will be accepted for filing if authorization of the facilities requested would be inconsistent with international commitments of the United States under treaties and other international agreements arrangements and understandings See list of such international instruments in 73 1650 b Any such application that is inadvertently accepted for filing will be dismissed b AM applications that involve conflicts only with the North American Regional Broadcasting Agreement NARBA but that are in conformity with the remaining treaties and other international agreements listed in 73 1650 b and with the other requirements of this part 73 will be granted subject to such modifications as the FCC may subsequently find appropriate taking international considerations into account c In the case of any application designated for hearing on issues other than those related to consistency with international relationships and as to which no final decision has been rendered whenever action under this section becomes appropriate because of inconsistency with international relationships the 47 CFR 73 23 c enhanced display page 17 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 23 d Radio Broadcast Services applicant involved shall notwithstanding the provisions 73 3522 and 73 3571 be permitted to amend its application to achieve consistency with such relationships In such cases the provisions of 73 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
3605 c will apply d In some circumstances special international considerations may require that the FCC in acting on applications follow procedures different from those established for general use In such cases affected applicants will be informed of the procedures to be followed 56 FR 64856 Dec 12 1991 73 24 Broadcast facilities showing required An authorization for a new AM broadcast station or increase in facilities of an existing station will be issued only after a satisfactory showing has been made in regard to the following among others a That the proposed assignment will tend to effect a fair efficient and equitable distribution of radio service among the several states and communities b That a proposed new station or a proposed change in the facilities of an authorized station complies with the pertinent requirements of 73 37 of this chapter c That the applicant is financially qualified to construct and operate the proposed station d That the applicant is legally qualified That the applicant or the person or persons in control of an applicant corporation or other organization is of good character and possesses other qualifications sufficient to provide a satisfactory public service e That the technical equipment proposed the location of the transmitter and other technical phases of operation comply with the regulations governing the same and the requirements of good engineering practice f That the facilities sought are subject to assignment as requested under existing international agreements and the rules and regulations of the Commission g That the population within the 1 V m contour does not exceed 1 0 percent of the population within the 25 mV m contour Provided however That where the number of persons within the 1 V m contour is 300 or less the provisions of this paragraph are not applicable h | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
That in the case of an application for a Class B or Class D station on a clear channel the proposed station would radiate during two hours following local sunrise and two hours preceding local sunset in any direction toward the 0 1 mV m groundwave contour of a co channel United States Class A station no more than the maximum value permitted under the provisions of 73 187 i That for all proposals for new stations applications to modify a construction permit for an unlicensed station and all applications to change a station s community of license the daytime 5 mV m contour encompasses the entire principal community to be served That for all other applications for modification of licensed stations the daytime 5 mV m contour encompasses either 50 percent of the area or 50 percent of the population of the principal community to be served That for all proposals for new stations in the 535 1605 kHz band applications to modify a construction permit for an unlicensed station or applications to change a station s community of license either 50 percent of the area or 50 percent of the population of the principal community is encompassed by the nighttime 5 mV m contour or the nighttime interference free contour whichever value is higher That for stations in the 1605 1705 kHz band 50 47 CFR 73 24 i enhanced display page 18 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 24 j Radio Broadcast Services percent of the principal community is encompassed by the nighttime 5 mV m contour or the nighttime interference free contour whichever value is higher That Class D stations with nighttime authorizations need not demonstrate such coverage during nighttime operation j That the public | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
interest convenience and necessity will be served through the operation under the proposed assignment 28 FR 13574 Dec 14 1963 as amended at 38 FR 5874 Mar 5 1973 49 FR 43960 Nov 1 1984 50 FR 40014 Oct 1 1985 52 FR 11654 Apr 10 1987 53 FR 1031 Jan 15 1988 56 FR 64857 Dec 12 1991 81 FR 2759 Jan 19 2016 73 25 Clear channels Class A Class B and Class D stations The frequencies in the following tabulations are designated as clear channels and assigned for use by the Classes of stations given a On each of the following channels one Class A station may be assigned operating with power of 50 kW 640 650 660 670 700 720 750 760 770 780 820 830 840 870 880 890 1020 1030 1040 1100 1120 1160 1180 1200 and 1210 kHz In Alaska these frequencies can be used by Class A stations subject to the conditions set forth in 73 182 a 1 ii On the channels listed in this paragraph Class B and Class D stations may be assigned b To each of the following channels there may be assigned Class A Class B and Class D stations 680 710 810 850 940 1000 1060 1070 1080 1090 1110 1130 1140 1170 1190 1500 1510 1520 1530 1540 1550 and 1560 kHz Note Until superseded by a new agreement protection of the Bahama Islands shall be in accordance with NARBA Accordingly a Class A Class B or Class D station on 1540 kHz shall restrict its signal to a value no greater than 5 µV m groundwave or 25 µV m 10 skywave at any point of land in the Bahama Islands and such stations operating nighttime i e sunset to sunrise at the location | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
of the U S station shall be located not less than 650 miles from the nearest point of land in the Bahama Islands c Class A Class B and Class D stations may be assigned on 540 690 730 740 800 860 900 990 1010 1050 1220 1540 1570 and 1580 kHz 28 FR 13574 Dec 14 1963 as amended at 33 FR 4410 Mar 12 1968 35 FR 18052 Nov 25 1970 47 FR 27862 June 28 1982 49 FR 43960 Nov 1 1984 50 FR 24520 June 11 1985 52 FR 47568 Dec 15 1987 53 FR 1031 Jan 15 1988 54 FR 39736 Sept 28 1989 56 FR 64857 Dec 12 1991 73 26 Regional channels Class B and Class D stations a The following frequencies are designated as regional channels and are assigned for use by Class B and Class D stations 550 560 570 580 590 600 610 620 630 790 910 920 930 950 960 970 980 1150 1250 1260 1270 1280 1290 1300 1310 1320 1330 1350 1360 1370 1380 1390 1410 1420 1430 1440 1460 1470 1480 1590 1600 1610 1620 1630 1640 1650 1660 1670 1680 1690 and 1700 kHz 47 CFR 73 26 a enhanced display page 19 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 26 b Radio Broadcast Services b Additionally in Alaska Hawaii Puerto Rico and the U S Virgin Islands the frequencies 1230 1240 1340 1400 1450 and 1490 kHz are designated as Regional channels and are assigned for use by Class B stations Stations formerly licensed to these channels in those locations as Class C stations are redesignated as Class B stations 56 FR 64857 Dec 12 1991 73 27 Local channels Class C stations Within | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
the conterminous 48 states the following frequencies are designated as local channels and are assigned for use by Class C stations 1230 1240 1340 1400 1450 and 1490 kHz 56 FR 64857 Dec 12 1991 73 28 Assignment of stations to channels a The Commission will not make an AM station assignment that does not conform with international requirements and restrictions on spectrum use that the United States has accepted as a signatory to treaties conventions and other international agreements See 73 1650 for a list of pertinent treaties conventions and agreements and 73 23 for procedural provisions relating to compliance with them b Engineering standards now in force domestically differ in some respects from those specified for international purposes The engineering standards specified for international purposes see 73 1650 International Agreements will be used to determine 1 The extent to which interference might be caused by a proposed station in the United States to a station in another country and 2 whether the United States should register an objection to any new or changed assignment notified by another country The domestic standards in effect in the United States will be used to determine the extent to which interference exists or would exist from a foreign station where the value of such interference enters into a calculation of i The service to be rendered by a proposed operation in the United States or ii the permissible interfering signal from one station in the United States to another United States station 28 FR 13574 Dec 14 1963 as amended at 29 FR 9499 July 11 1964 49 FR 32358 Aug 14 1984 50 FR 18821 May 2 1985 54 FR 39736 Sept 28 1989 56 FR 64857 Dec 12 1991 73 29 Class C stations on regional channels No license will | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
be granted for the operation of a Class C station on a regional channel 56 FR 64857 Dec 12 1991 47 CFR 73 29 enhanced display page 20 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 30 Radio Broadcast Services 73 30 Petition for authorization of an allotment in the 1605 1705 kHz band a Any party interested in operating an AM broadcast station on one of the ten channels in the 1605 1705 kHz band must file a petition for the establishment of an allotment to its community of license Each petition must include the following information 1 Name of community for which allotment is sought 2 Frequency and call letters of the petitioner s existing AM operation and 3 Statement as to whether or not AM stereo operation is proposed for the operation in the 1605 1705 kHz band b Petitions are to be filed during a filing period to be determined by the Commission For each filing period eligible stations will be allotted channels based on the following steps 1 Stations are ranked in descending order according to the calculated improvement factor 2 The station with the highest improvement factor is initially allotted the lowest available channel 3 Successively each station with the next lowest improvement factor is allotted an available channel taking into account the possible frequency and location combinations and relationship to previously selected allotments If a channel is not available for the subject station previous allotments are examined with respect to an alternate channel the use of which would make a channel available for the subject station 4 When it has been determined that in accordance with the above steps no channel is available for the subject station that station is no longer considered and | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
the process continues to the station with the next lowest improvement factor c If awarded an allotment a petitioner will have sixty 60 days from the date of public notice of selection to file an application for construction permit on FCC Form 301 See 73 24 and 73 37 e for filing requirements Unless instructed by the Commission to do otherwise the application shall specify Model I facilities See 73 14 Upon grant of the application and subsequent construction of the authorized facility the applicant must file a license application on FCC Form 302 Note 1 Until further notice by the Commission the filing of these petitions is limited to licensees of existing AM stations excluding Class C stations operating in the 535 1605 kHz band First priority will be assigned to Class D stations located within the primary service contours of U S Class A stations that are licensed to serve communities of 100 000 or more for which there exists no local fulltime aural service Note 2 Selection among competing petitions will be based on interference reduction Notwithstanding the exception contained in Note 5 of this section within each operational category the station demonstrating the highest value of improvement factor will be afforded the highest priority for an allotment with the next priority assigned to the station with next lowest value and so on until available allotments are filled 47 CFR 73 30 c enhanced display page 21 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 30 c Radio Broadcast Services Note 3 The Commission will periodically evaluate the progress of the movement of stations from the 535 1605 kHz band to the 1605 1705 kHz band to determine whether the 1605 1705 kHz band should continue to be | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
administered on an allotment basis or modified to an assignment method If appropriate the Commission will later develop further procedures for use of the 1605 1705 kHz band by existing station licensees and others Note 4 Other than the exception specified in note 1 of this section existing fulltime stations are considered first for selection as described in note 2 of this section In the event that an allotment availability exists for which no fulltime station has filed a relevant petition such allotment may be awarded to a licensed Class D station If more than one Class D station applies for this migration opportunity the following priorities will be used in the selection process First priority a Class D station located within the 0 5 mV m 50 contour of a U S Class A station and licensed to serve a community of 100 000 or more for which there exists no local fulltime aural service Second priority Class D stations ranked in order of improvement factor from highest to lowest considering only those stations with improvement factors greater than zero Note 5 The preference for AM stereo in the expanded band will be administered as follows when an allotment under consideration candidate allotment conflicts with one or more previously selected allotments established allotments and cannot be accommodated in the expanded band the candidate allotment will be substituted for the previously established allotment provided that the petitioner for the candidate allotment has made a written commitment to the use of AM stereo and the petitioner for the established allotment has not the difference between the ranking factors associated with the candidate and established allotments does not exceed 10 of the ranking factor of the candidate allotment the substitution will not require the displacement of more than one established allotment and | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
both the candidate allotment and the established allotment are within the same priority group 58 FR 27949 May 12 1993 47 CFR 73 30 c enhanced display page 22 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 31 Radio Broadcast Services 73 31 Rounding of nominal power specified on applications a An application filed with the FCC for a new station or for an increase in power of an existing station shall specify nominal power rounded to two significant figures as follows Nominal power kW Rounded down to nearest figure kW Below 0 25 0 001 0 25 to 0 99 0 01 1 to 9 9 0 1 10 to 50 1 b In rounding the nominal power in accordance with paragraph a of this section the RMS shall be adjusted accordingly If rounding upward to the nearest figure would result in objectionable interference the nominal power specified on the application is to be rounded downward to the next nearest figure and the RMS adjusted accordingly 50 FR 18821 May 2 1985 as amended at 53 FR 1031 Jan 15 1988 73 33 Antenna systems showing required a An application for authority to install a broadcast antenna shall specify a definite site and include full details of the antenna design and expected performance b All data necessary to show compliance with the terms and conditions of the construction permit must be filed with the license application If the station is using a directional antenna a proof of performance must also be filed 28 FR 13574 Dec 14 1963 as amended at 37 FR 25840 Dec 5 1972 73 35 Calculation of improvement factors A petition for an allotment See 73 30 in the 1605 1705 kHz band filed by an | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
existing fulltime AM station licensed in the 535 1605 kHz band will be ranked according to the station s calculated improvement factor See 73 30 Improvement factors relate to both nighttime and daytime interference conditions and are based on two distinct considerations a Service area lost by other stations due to interference caused by the subject station and b service area of the subject station These considerations are represented by a ratio The ratio consists where applicable of two separate additive components one for nighttime and one for daytime For the nighttime component to determine the numerator of the ratio first consideration calculate the RSS and associated service area of the stations co and adjacent channel to which the subject station causes nighttime interference Next repeat the RSS and service area calculations excluding the subject station The cumulative gain in the above service area is the numerator of the ratio The denominator second consideration is the subject station s interference free service area For the daytime component the composite amount of service lost by co channel and adjacent channel stations each taken individually that are affected by the subject station excluding the effects of other assignments during each study will be used as the numerator of the daytime improvement factor The denominator will consist of the actual daytime service area 0 5 mV m contour less any area lost to interference from other assignments The value of this combined ratio will constitute the petitioner s improvement factor Notwithstanding the 47 CFR 73 35 enhanced display page 23 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 37 Radio Broadcast Services requirements of 73 153 for uniform comparisons and simplicity measurement data will not be used for determining improvement factors and FCC figure | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
M 3 ground conductivity values are to be used exclusively in accordance with the pertinent provisions of 73 183 c 1 56 FR 64858 Dec 12 1991 73 37 Applications for broadcast facilities showing required a No application will be accepted for a new station if the proposed operation would involve overlap of signal strength contours with any other station as set forth below in this paragraph and no application will be accepted for a change of the facilities of an existing station if the proposed change would involve such overlap where there is not already such overlap between the stations involved Frequency separation Contour of proposed station classes B C and Contour of any other station kHz D mV m mV m 0 0 005 0 100 Class A 0 025 0 500 Other classes 0 500 0 025 All classes 10 0 250 0 500 All classes 0 500 0 250 All classes 20 5 5 All classes 5 5 All classes 30 25 25 All classes b In determining overlap received an application for a new Class C station with daytime power of 250 watts or greater shall be considered on the assumption that both the proposed operation and all existing Class C stations operate with 250 watts and utilize non directional antennas c If otherwise consistent with the public interest an application requesting an increase in the daytime power of an existing Class C station on a local channel from 250 watts to a maximum of 1kW or from 100 watts to a maximum of 500 watts may be granted notwithstanding overlap prohibited by paragraph a of this section In the case of a 100 watt Class C station increasing daytime power the provisions of this paragraph shall not be construed to permit an increase in | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
power to more than 500 watts if prohibited overlap would be involved even if successive applications should be tendered d In addition to demonstrating compliance with paragraphs a and as appropriate b and c of this section an application for a new AM broadcast station or for a major change see 73 3571 a 1 in an authorized AM broadcast station as a condition for its acceptance shall make a satisfactory showing if new or modified nighttime operation by a Class B station is proposed that objectionable interference will not result to an authorized station as determined pursuant to 73 182 1 e An application for an authorization in the 1605 1705 kHz band which has been selected through the petition process See 73 30 is not required to demonstrate compliance with paragraph a b c or d of this section Instead the applicant need only comply with the terms of the allotment authorization issued by the Commission in response to the earlier petition for establishment of a station in the 1605 1705 kHz band Within the allotment authorization the Commission will specify the assigned frequency and the applicable technical requirements 47 CFR 73 37 e enhanced display page 24 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 37 f Radio Broadcast Services f Stations on 1580 1590 and 1600 kHz In addition to the rules governing the authorization of facilities in the 535 1605 kHz band stations on these frequencies seeking facilities modifications must protect assignments in the 1610 1700 kHz band Such protection shall be afforded in a manner which considers the spacings that occur or exist between the subject station and a station within the range 1605 1700 kHz The spacings are the same as those specified for | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
stations in the frequency band 1610 1700 kHz or the current separation distance whichever is greater Modifications that would result in a spacing or spacings that fails to meet any of the separations must include a showing that appropriate adjustment has been made to the radiated signal which effectively results in a site to site radiation that is equivalent to the radiation of a station with standard Model I facilities 10 kW D 1 kW N non DA 90 degree antenna ht ground system operating in compliance with all of the above separation distances In those cases where that radiation equivalence value is already exceeded a station may continue to maintain but not increase beyond that level Note 1 In the case of applications for changes in the facilities of AM broadcast stations covered by this section an application will be accepted even though overlap of field strength contours as mentioned in this section would occur with another station in an area where such overlap does not already exist if 1 The total area of overlap with that station would not be increased 2 There would be no net increase in the area of overlap with any other station and 3 There would be created no area of overlap with any station with which overlap does not now exist Note 2 The provisions of this section concerning prohibited overlap of field strength contours will not apply where 1 The area of overlap lies entirely over sea water or 2 The only overlap involved would be that caused to a foreign station in which case the provisions of the applicable international agreement as identified in 73 1650 will apply When overlap would be received from a foreign station the provisions of this section will apply except where there would be overlap | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
with a foreign station with a frequency separation of 20 kHz in which case the provisions of the international agreement will apply in lieu of this section Note 3 In determining the number of authorized aural transmission facilities in a given community applications for that community in hearing or otherwise having protected status under specified cut off procedures shall be considered as existing stations In the event that there are two or more mutually exclusive protected applications seeking authorization for the proposed community it will be assumed that only one is authorized 47 CFR 73 37 f enhanced display page 25 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 44 Radio Broadcast Services Note 4 A transmission facility for a community is a station licensed to the community Such a station provides a transmission service for that community 56 FR 64858 Dec 12 1991 57 FR 43290 Sept 18 1992 73 44 AM transmission system emission limitations a The emissions of stations in the AM service shall be attenuated in accordance with the requirements specified in paragraph b of this section Emissions shall be measured using a properly operated and suitable swept frequency RF spectrum analyzer using a peak hold duration of 10 minutes no video filtering and a 300 Hz resolution bandwidth except that a wider resolution bandwidth may be employed above 11 5 kHz to detect transient emissions Alternatively other specialized receivers or monitors with appropriate characteristics may be used to determine compliance with the provisions of this section provided that any disputes over measurement accuracy are resolved in favor of measurements obtained by using a calibrated spectrum analyzer adjusted as set forth above b Emissions 10 2 kHz to 20 kHz removed from the carrier must be attenuated | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
at least 25 dB below the unmodulated carrier level emissions 20 kHz to 30 kHz removed from the carrier must be attenuated at least 35 dB below the unmodulated carrier level emissions 30 kHz to 60 kHz removed from the carrier must be attenuated at least 5 1 dB kHz below the unmodulated carrier level and emissions between 60 kHz and 75 kHz of the carrier frequency must be attenuated at least 65 dB below the unmodulated carrier level Emissions removed by more than 75 kHz must be attenuated at least 43 10 Log Power in watts or 80 dB below the unmodulated carrier level whichever is the lesser attenuation except for transmitters having power less than 158 watts where the attenuation must be at least 65 dB below carrier level c Should harmful interference be caused to the reception of other broadcast or non broadcast stations by out of band emissions the licensee may be directed to achieve a greater degree of attentuation than specified in paragraphs a and b of this section d Measurements to determine compliance with this section for transmitter type acceptance are to be made using signals sampled at the output terminals of the transmitter when operating into an artificial antenna of substantially zero reactance Measurements made of the emissions of an operating station are to be made at ground level approximately 1 kilometer from the center of the antenna system When a directional antenna is used the carrier frequency reference field strength to be used in order of preference shall be 1 The measure non directional field strength 2 The RMS field strength determined from the measured directional radiation pattern 3 The calculated expected field strength that would be radiated by a non directional antenna at the station authorized power e Licensees of stations | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
complying with the ANSI EIA 549 1988 NRSC 1 AM Preemphasis Deemphasis and Broadcast Transmission Bandwidth Specifications NRSC 1 prior to June 30 1990 or from the original commencement of operation will until June 30 1994 be considered to comply with paragraphs a and b of this section absent any reason for the Commission to believe otherwise Such stations are waived from having to make the periodic measurements required in 73 1590 a 6 until June 30 1994 47 CFR 73 44 e enhanced display page 26 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 45 Radio Broadcast Services However licensees must make measurements to determine compliance with paragraphs a and b of this section upon receipt of an Official Notice of Violation or a Notice of Apparent Liability alleging noncompliance with those provisions or upon specific request by the Commission 47 FR 8588 Mar 1 1982 as amended at 49 FR 3999 Feb 1 1984 73 45 AM antenna systems a All applicants for new additional or different AM station facilities and all licensees requesting authority to change the transmitting system site of an existing station must specify an antenna system the efficiency of which complies with the requirements for the class and power of station See 73 186 and 73 189 1 An application for authority to install an AM broadcast antenna must specify a definite site and include full details of the antenna system design and expected performance 2 All data necessary to show compliance with the terms and conditions of the construction permit must be filed with the application for the station license to cover the construction If the station has constructed a directional antenna a directional proof of performance must be filed See 73 150 through | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
73 157 b The simultaneous use of a common antenna or antenna structure by more than one AM station or by a station of any other type or service may be authorized provided 1 Engineering data are submitted showing that satisfactory operation of each station will be obtained without adversely affecting the operation of the other station s 2 The minimum field strength for each AM station complies with 73 189 b c Should any changes be made or otherwise occur which would possibly alter the resistance of the antenna system the licensee must commence the determination of the operating power by a method described in 73 51 a 1 or d If the changes are due to the addition of antennas to the AM tower see 1 30003 Upon completion of any necessary repairs or adjustments or upon completion of authorized construction or modifications the licensee must make a new determination of the antenna resistance using the procedures described in 73 54 Operating power should then be determined by a direct method as described in 73 51 Notification of the value of resistance of the antenna system must be filed with the FCC in Washington DC as follows 1 Whenever the measurements show that the antenna or common point resistance differs from that shown on the station authorization by more than 2 FCC Form 302 must be filed with the information and measurement data specified in 73 54 d 2 Whenever AM stations use direct reading power meters pursuant to 73 51 a letter notification to the FCC in Washington DC Attention Audio Division Media Bureau must be filed in accordance with 73 54 e 43 FR 53735 Nov 17 1978 as amended at 45 FR 28141 Apr 28 1980 47 FR 8589 Mar 1 1982 50 FR 32416 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
Aug 12 1985 51 FR 2707 Jan 21 1986 51 FR 26250 July 22 1986 63 FR 33875 June 22 1998 67 FR 13231 Mar 21 2002 78 FR 66298 Nov 5 2013 47 CFR 73 45 d 2 enhanced display page 27 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 49 Radio Broadcast Services 73 49 AM transmission system fencing requirements Antenna towers having radio frequency potential at the base series fed folded unipole and insulated base antennas must be enclosed within effective locked fences or other enclosures Ready access must be provided to each antenna tower base for meter reading and maintenance purposes at all times However individual tower fences need not be installed if the towers are contained within a protective property fence 51 FR 2707 Jan 21 1986 73 51 Determining operating power a Except in those circumstances described in paragraph d of this section the operating power shall be determined by the direct method The direct method consists of either 1 using a suitable instrument for determining the antenna s input power directly from the RF voltage RF current and phase angle or 2 calculating the product of the licensed antenna or common point resistance at the operating frequency see 73 54 and the square of the indicated unmodulated antenna current at that frequency measured at the point where the resistance has been determined b The authorized antenna input power for each station shall be equal to the nominal power for such station with the following exceptions 1 For stations with nominal powers of 5 kW or less the authorized antenna input power to directional antennas shall exceed the nominal power by 8 percent 2 For stations with nominal powers in excess of 5 kW the | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
authorized antenna input power to directional antennas shall exceed the nominal power by 5 3 percent 3 In specific cases it may be necessary to limit the radiated field to a level below that which would result if normal power were delivered to the antenna In such cases excess power may be dissipated in the antenna feed circuit the transmitter may be operated with power output at a level which is less than the rated carrier power or a combination of the two methods may be used subject to the conditions given in paragraph c of this section i Where a dissipative network is employed the authorized antenna current and resistance and the authorized antenna input power shall be determined at the input terminals of the dissipative network ii Where the authorized antenna input power is less than the nominal power subject to the conditions set forth in paragraph c of this section the transmitter may be operated at the reduced power level necessary to supply the authorized antenna input power c Applications for authority to operate with antenna input power which is less than nominal power and or to employ a dissipative network in the antenna system shall be made on FCC Form 302 The technical information supplied on section II A of this form shall be that applying to the proposed conditions of operation In addition the following information shall be furnished as pertinent 1 Full details of any network employed for the purpose of dissipating radio frequency energy otherwise delivered to the antenna see 73 54 2 A showing that the transmitter has been type accepted or notified for operation at the proposed power output level or in lieu thereof 47 CFR 73 51 c 2 enhanced display page 28 of 580 47 CFR Part 73 up | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
to date as of 2 20 2024 47 CFR 73 51 c 2 i Radio Broadcast Services i A full description of the means by which transmitter output power will be reduced ii Where the proposed transmitter power output level s is less than 90 of the rated power of the transmitter equipment performance measurements must be made to confirm that the station transmissions conform to the emission limitation specified in 73 44 under all conditions of program operation iii A showing that at the proposed power output level means are provided for varying the transmitter output within a tolerance of 10 percent to compensate for variations in line voltage or other factors which may affect the power output level d When it is not possible or appropriate to use the direct method of power determination due to technical reasons the indirect method of determining operating power see paragraphs e and f of this section may be used on a temporary basis A notation must be made in the station log indicating the dates of commencement and termination of measurement using the indirect method of power determination e The antenna input power is determined indirectly by applying an appropriate factor to the input power to the last radio frequency power amplifier stage of the transmitter using the following formula Where Antenna input power Ep Ip F Ep DC input voltage of final radio stage Ip Total DC input current of final radio stage F Efficiency factor 1 If the above formula is not appropriate for the design of the transmitter final amplifier use a formula specified by the transmitter manufacturer with other appropriate operating parameters 2 The value of F applicable to each mode of operation must be determined and a record kept thereof with a notation as to its | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
derivation This factor is to be established by one of the methods described in paragraph f of this section and retained in the station records f The value of F is to be determined by one of the following procedures listed in order of preference 1 If the station had previously been authorized and operating by determining the antenna input power by the direct method the factor F is the ratio of the antenna input power determined by the direct method to the corresponding final radio frequency power amplifier input power 2 If a station has not been previously in regular operation with the power authorized for the period of indirect power determination if a new transmitter has been installed or if for any other reason the determination of the factor F by the method described in paragraph f 1 of this section is impracticable i The factor F as shown in the transmitter manufacturer s test report if such a test report specifies a unique value of F for the power level and frequently used or ii The value determined by reference to the following table Factor F Method of modulation Maximum rated carrier power Class of amplifier 0 70 Plate 1 kW or less 47 CFR 73 51 f 2 ii enhanced display page 29 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 53 Radio Broadcast Services Factor F Method of modulation Maximum rated carrier power Class of amplifier 80 Plate 2 5 kW and over 35 Low level 0 25 kW and over B 65 Low level 0 25 kW and over BC1 35 Grid 0 25 kW and over 1 All linear amplifier operation where efficiency approaches that of class C operation 37 FR 7516 Apr 15 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
1972 as amended at 42 FR 36827 July 18 1977 42 FR 61863 Dec 7 1977 44 FR 36036 June 20 1979 47 FR 28387 June 30 1982 48 FR 38477 Aug 24 1983 48 FR 44805 Sept 30 1983 49 FR 3999 Feb 1 1984 49 FR 4210 Feb 3 1984 49 FR 49850 Dec 24 1984 50 FR 24521 June 11 1985 52 FR 10570 Apr 2 1987 83 FR 48963 Sept 28 2018 73 53 Requirements for authorization of antenna monitors a Antenna monitors shall be approved with Supplier s Declaration of Conformity that demonstrates compliance with the technical requirements in this section The procedure for Supplier s Declaration of Conformity is specified in subpart J of part 2 of this chapter Note 1 to paragraph a The verification procedure has been replaced by Supplier s Declaration of Conformity Antenna monitors previously authorized under subpart J of part 2 of this chapter may remain in use See 2 950 of this chapter b An antenna monitor shall meet the following specifications 1 The monitor shall be designed to operate in the 535 1705 kHz band 2 The monitor shall be capable of indicating any phase difference between two RF voltages of the same frequency over a range of from 0 to 360 3 The monitor shall be capable of indicating the relative amplitude of two RF voltages 4 The device used to indicate phase differences shall indicate in degrees and shall be graduated in increments of 2 or less If a digital indicator is provided the smallest increment shall be 0 5 or less 5 The device used to indicate relative amplitudes shall be graduated in increments which are 1 percent or less of the full scale value If a digital indicator is provided the smallest increment | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
shall be 0 1 percent or less of the full scale value 6 The monitor shall be equipped with means if necessary to resolve ambiguities in indication 7 If the monitor is provided with more than one RF input terminal in addition to a reference input terminal appropriate switching shall be provided in the monitor so that the signal at each of these RF inputs may be selected separately for comparison with the reference input signal 8 Each RF input of the monitor shall provide a termination of such characteristics that when connected to a sampling line of an impedance specified by the manufacturer the voltage reflection coefficient shall be 3 percent or less 47 CFR 73 53 b 8 enhanced display page 30 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 53 b 9 Radio Broadcast Services 9 The monitor if intended for use by stations operating directional antenna systems by remote control shall be designed so that the switching functions required by paragraph b 7 of this section may be performed from a point external to the monitor and phase and amplitude indications be provided by external meters The indications of external meters furnished by the manufacturer shall meet the specifications for accuracy and repeatability of the monitor itself and the connection of these meters to the monitor or of other indicating instruments with electrical characteristics meeting the specifications of the monitor manufacturer shall not affect adversely the performance of the monitor in any respect 10 Complete and correct schematic diagrams and operating instructions shall be retained by the party responsible for Supplier s Declaration of Conformity of the equipment and submitted to the FCC upon request For the purpose of equipment authorization these diagrams and instructions shall be | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
considered as part of the monitor 11 When an RF signal of an amplitude within a range specified by the manufacturer is applied to the reference RF input terminal of the monitor and another RF signal of the same frequency and of equal or lower amplitude is applied to any other selected RF input terminal indications shall be provided meeting the following specifications i The accuracy with which any difference in the phases of the applied signals is indicated shall be 1 or better for signal amplitude ratios of from 2 1 to 1 1 and 2 or better for signal amplitude ratios in excess of 2 1 and up to 5 1 ii The repeatability of indication of any difference in the phases of the applied signals shall be 1 or better iii The accuracy with which the relative amplitudes of the applied signals is indicated over a range in which the ratio of these amplitudes is between 2 1 and 1 1 shall be 2 percent of the amplitude ratio or better and for amplitude ratios in excess of 2 1 and up to 5 1 5 percent of the ratio or better iv The repeatability of indication of the relative amplitudes of the applied signals over a range where the ratio of these amplitudes is between 5 1 and 1 1 shall be 2 percent of the amplitude ratio or better v The modulation of the RF signals by a sinusoidal wave of any frequency between 100 and 10 000 Hz at any amplitude up to 90 percent shall cause no deviation in an indicated phase difference from its value as determined without modulation greater than 0 5 12 The performance specifications set forth in paragraph b 11 of this section shall be met when the monitor | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
is operated and tested under the following conditions i After continuous operation for 1 hour the monitor shall be calibrated and adjusted in accordance with the manufacturer s instructions ii The monitor shall be subjected to variations in ambient temperature between the limits of 10 and 40 C external meters furnished by the manufacturer will be subjected to variations between 15 and 30 C iii Powerline supply voltage shall be varied over a range of from 10 percent below to 10 percent above the rated supply voltage 47 CFR 73 53 b 12 iii enhanced display page 31 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 53 b 12 iv Radio Broadcast Services iv The amplitude of the reference signal shall be varied over the operating range specified by the manufacturer and in any case over a range of maximum to minimum values of 3 to 1 v The amplitude of the comparison signal shall be varied from a value which is 0 2 of the amplitude of the reference signal to a value which is equal in amplitude to the reference signal vi Accuracy shall be determined for the most adverse combination of conditions set forth above vii Repeatability shall be determined as that which may be achieved under the specified test conditions over a period of 7 days during which no calibration or adjustment of the instrument subsequent to the initial calibration shall be made viii The effects of modulation of the RF signal shall be separately determined and shall not be included in establishing values for accuracy and repeatability Note 1 to paragraph b In paragraph b 1 of this section the requirement that monitors be capable of operation in the 535 1705 kHz band shall apply only | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
to equipment manufactured after July 1 1992 Use of a monitor in the 1605 1705 kHz band which is not approved for such operation will be permitted pending the general availability of 535 1705 kHz band monitors if a manufacturer can demonstrate in the interim that its monitor performs in accordance with the standards in this section on these 10 channels Secs 4 5 303 48 Stat as amended 1066 1068 1082 47 U S C 154 155 303 38 FR 1917 Jan 19 1973 as amended at 49 FR 3999 Feb 1 1984 49 FR 29069 July 18 1984 50 FR 32416 Aug 12 1985 50 FR 47054 Nov 14 1985 51 FR 2707 Jan 21 1986 56 FR 64859 Dec 12 1991 57 FR 43290 Sept 18 1992 60 FR 55480 Nov 1 1995 63 FR 36604 July 7 1998 66 FR 20755 Apr 25 2001 82 FR 50835 Nov 2 2017 73 54 Antenna resistance and reactance measurements a The resistance of an omnidirectional series fed antenna is measured at either the base of the antenna without intervening coupling or tuning networks or at the point the transmission line connects to the output terminals of the transmitter The resistance of a shunt excited antenna may be measured at the point the radio frequency energy is transferred to the feed wire circuit or at the output terminals of the transmitter b The resistance and reactance of a directional antenna shall be measured at the point of common radiofrequency input to the directional antenna system after the antenna has been finally adjusted for the required radiation pattern c A letter of notification must be filed with the FCC in Washington DC Attention Audio Division Media Bureau when determining power by the direct method pursuant to 73 51 The letter | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
must specify the antenna or common point resistance at the operating frequency The following information must also be kept on file at the station 1 A full description of the method used to make measurements 2 A schematic diagram showing clearly all components of coupling circuits the point of resistance measurement the location of the antenna ammeter connections to and characteristics of all tower lighting isolation circuits static drains and any other fixtures connected to and supported by the antenna including other antennas and associated networks Any network or circuit component used 47 CFR 73 54 c 2 enhanced display page 32 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 54 d Radio Broadcast Services to dissipate radio frequency power shall be specifically identified and the impedances of all components which control the level of power dissipation and the effective input resistance of the network must be indicated d AM stations using direct reading power meters in accordance with 73 51 can either submit the information required by paragraph c of this section or submit a statement indicating that such a meter is being used Subsequent station licenses will indicate the use of a direct reading power meter in lieu of the antenna resistance value in such a situation 66 FR 20755 Apr 25 2001 as amended at 67 FR 13231 Mar 21 2002 73 57 Remote reading antenna and common point ammeters Remote reading antenna and common point ammeters may be used without further authority according to the following conditions a Remote reading antenna or common point ammeters may be provided by 1 Inserting second radio frequency current sensing device directly in the antenna circuit with remote leads to the indicating instruments 2 Inductive coupling to radio frequency current sensing | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
device for providing direct current to indicating instrument 3 Capacity coupling to radio frequency current sensing device for providing direct current to indicating instrument 4 Current transformer connected to radio frequency current sensing device for providing direct current to indicating instrument 5 Using transmission line current meter at transmitter as remote reading ammeter See paragraph c of this section 6 Using the indications of the antenna phase monitor provided that when the monitor is used to obtain remote reading indication of non directional antenna base current the monitor calibration can be independently made and maintained for each mode of operation b Devices used for obtaining remote reading antenna or common point current indications except antenna monitor coupling elements shall be located at the same point as but below transmitter side the associated main ammeter c In the case of shunt excited antennas the transmission line current meter at the transmitter may be considered as the remote antenna ammeter provided the transmission line is terminated directly into the excitation circuit feed line which shall employ series tuning only no shunt circuits of any type shall be employed and insofar as practicable the type and scale of the transmission line meter should be the same as those of the excitation circuit feed line meter meter in slant wire feed line or equivalent d Each remote reading ammeter shall be accurate to within 2 percent of the value read on its corresponding regular ammeter e All remote reading ammeters shall conform with the specifications for regular antenna ammeters 47 CFR 73 57 e enhanced display page 33 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 57 f Radio Broadcast Services f Meters with arbitrary scale divisions may be used provided that calibration charts or | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
curves are provided at the transmitter control point showing the relationship between the arbitrary scales and the reading of the main meters g If a malfunction affects the remote reading indicators of the antenna or common point ammeter the operating power may be determined by a method using alternative procedures as described in 73 51 41 FR 36817 Sept 1 1976 as amended at 48 FR 38477 Aug 24 1983 49 FR 49850 Dec 24 1984 50 FR 32416 Aug 12 1985 60 FR 55480 Nov 1 1995 73 58 Indicating instruments a Each AM broadcast station must be equipped with indicating instruments which conform with the specifications described in 73 1215 for determining power by the direct and indirect methods and with such other instruments as are necessary for the proper adjustment operation and maintenance of the transmitting system However auxiliary transmitters with a nominal power rating of 100 watts or less are not required to be equipped with instruments to determine power by the indirect method provided that the licensee can determine the antenna input power at all times b Since it is usually impractical to measure the actual antenna current of a shunt excited antenna system the current measured at the input of the excitation circuit feed line is accepted as the antenna current c The function of each instrument shall be clearly and permanently shown on the instrument itself or on the panel immediately adjacent thereto d In the event that any one of these indicating instruments becomes defective when no substitute which conforms with the required specifications is available the station may be operated without the defective instrument pending its repair or replacement for a period not in excess of 60 days without further authority of the Commission If the defective instrument is the antenna | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
current meter of a nondirectional station which does not employ a remote antenna ammeter or if the defective instrument is the common point meter of a station which employs a directional antenna and does not employ a remote common point meter the operating power shall be determined by a method described in 73 51 a 1 or 73 51 d during the entire time the station is operated without the antenna current meter or common point meter However if a remote meter is employed and the antenna current ammeter or common point meter becomes defective the remote meter can be used to determine operating power pending the return to service of the regular meter e If conditions beyond the control of the licensee prevent the restoration of the meter to service within the above allowed period information requested in accordance with 73 3549 may be filed by letter with the FCC in Washington DC Attention Audio Division Media Bureau to request additional time as may be required to complete repairs of the defective instrument 41 FR 36817 Sept 1 1976 as amended at 48 FR 38477 Aug 24 1983 49 FR 49850 Dec 24 1984 50 FR 32416 Aug 12 1985 51 FR 2707 Jan 21 1986 53 FR 2498 Jan 28 1988 63 FR 33876 June 22 1998 66 FR 20755 Apr 25 2001 67 FR 13231 Mar 21 2002 73 61 AM directional antenna field strength measurements a Each AM station using a directional antenna with monitoring point locations specified in the instrument of authorization must make field strength measurements as often as necessary to ensure that the field at each of those points does not exceed the value specified in the station authorization Additionally 47 CFR 73 61 a enhanced display page 34 of 580 47 CFR | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
Part 73 up to date as of 2 20 2024 47 CFR 73 61 b Radio Broadcast Services stations not having an approved sampling system must make the measurements once each calendar quarter at intervals not exceeding 120 days The provision of this paragraph supersedes any schedule specified on a station license issued prior to January 1 1986 The results of the measurements are to be entered into the station log pursuant to the provisions of 73 1820 b If the AM license was granted on the basis of field strength measurements performed pursuant to 73 151 a partial proof of performance measurements using the procedures described in 73 154 must be made whenever the licensee has reason to believe that the radiated field may be exceeding the limits for which the station was most recently authorized to operate c A station may be directed to make a partial proof of performance by the FCC whenever there is an indication that the antenna is not operating as authorized 50 FR 47054 Nov 14 1985 as amended at 73 FR 64560 Oct 30 2008 73 62 Directional antenna system operation and tolerances a Each AM station operating a directional antenna must maintain the relative amplitudes of the antenna currents as indicated by the antenna monitor within 5 of the values specified on the instrument of authorization Directional antenna relative phases must be maintained within 3 degrees of the values specified on the instrument of authorization b In the event of a failure of system components improper pattern switching or any other event that results in operation substantially at variance from the radiation pattern specified in the instrument of authorization for the pertinent time of day operation must be terminated within three minutes unless power can be reduced sufficiently to eliminate any | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
excessive radiation See 73 1350 e 1 Any variation of operating parameters by more than 15 percent sample current ratio or 10 degrees in phase any monitor point that exceeds 125 percent of the licensed limit or any operation at variance that results in complaints of interference shall be considered operation substantially at variance from the license and will require immediate corrective action 2 Reserved c In the event of minor variations of directional antenna operating parameters from the tolerances specified in paragraph a of this section the following procedures will apply 1 The licensee shall measure and log every monitoring point at least once for each mode of directional operation Subsequent variations in operating parameters will require the remeasuring and logging of every monitoring point to assure that the authorized monitoring point limits are not being exceeded The licensee will be permitted 24 hours to accomplish these actions provided that the date and time of the failure to maintain proper operating parameters have been recorded in the station log 2 Provided each monitoring point is within its specified limit operation may continue for a period up to 30 days before a request for Special Temporary Authority STA must be filed pursuant to paragraph c 4 of this section to operate with parameters at variance from the provisions of paragraph a of this section 3 If any monitoring point exceeds its specified limit the licensee must either terminate operation within three hours or reduce power in accordance with the applicable provisions of 73 1350 d in order to eliminate any possibility of interference or excessive radiation in any direction 47 CFR 73 62 c 3 enhanced display page 35 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 62 c 4 Radio | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
Broadcast Services 4 If operation pursuant to paragraph c 3 of this section is necessary or before the 30 day period specified in paragraph c 2 of this expires the licensee must request a Special Temporary Authority STA in accordance with section 73 1635 to continue operation with parameters at variance and or with reduced power along with a statement certifying that all monitoring points will be continuously maintained within their specified limits d In any other situation in which it might reasonably be anticipated that the operating parameters might vary out of tolerance such as planned array repairs or adjustment and proofing procedures the licensee shall before such activity is undertaken obtain a Special Temporary Authority STA in accordance with 73 1635 in order to operate with parameters at variance and or with reduced power as required to maintain all monitoring points within their specified limits 72 FR 44422 Aug 8 2007 73 68 Sampling systems for antenna monitors a Each AM station permittee authorized to construct a new directional antenna system which will be subject to a proof of performance based on field strength measurements as described in 73 151 a or b must install the sampling system in accordance with the following specifications 1 Devices used to extract or sample the current and the transmission line connecting the sampling elements to the antenna monitor must provide accurate and stable signals to the monitor e g rigidly mounted and non rotatable loops and all system components protected from physical and environmental disturbances 2 Sampling lines for directional antennas may be of different lengths provided the phase difference of signals at the monitor are less than 0 5 degrees between the shortest and longest cable lengths due to temperature variations to which the system is exposed 3 Other configurations | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
of sampling systems may be used upon demonstration of stable operation to the FCC b An AM station permittee authorized to construct a directional antenna system which will be subject to a proof of performance based on moment method modeling as described in 73 151 c shall install a sampling system conforming to the requirements set forth in that section c A station having an antenna sampling system constructed according to the specifications given in paragraph a of this section may obtain approval of that system by submitting an informal letter request to the FCC in Washington DC Attention Audio Division Media Bureau The request for approval signed by the licensee or authorized representative must contain sufficient information to show that the sampling system is in compliance with all requirements of paragraph a of this section Note to paragraph c A public notice dated December 9 1985 giving additional information on approval of antenna sampling systems is available through the Internet at http www fcc gov mb audio decdoc letter 1985 12 09 sample html d In the event that the antenna monitor sampling system is temporarily out of service for repair or replacement the station may be operated pending completion of repairs or replacement for a period not exceeding 120 days without further authority from the FCC if all other operating parameters and the field monitoring point values are within the limits specified on the station authorization 47 CFR 73 68 d enhanced display page 36 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 68 e Radio Broadcast Services e If the antenna sampling system is modified or components of the sampling system are replaced the following procedure shall be followed 1 Special Temporary Authority see 73 1635 shall be | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
requested and obtained from the Commission s Audio Division Media Bureau in Washington to operate with parameters at variance with licensed values pending issuance of a modified license specifying parameters subsequent to modification or replacement of components 2 Immediately prior to modification or replacement of components of the sampling system and after a verification that all monitoring point values and operating parameters are within the limits or tolerances specified in the rules the following indications must be recorded for each radiation pattern Final plate current and plate voltage common point current antenna monitor phase and current indications and the field strength at each monitoring point Subsequent to these modifications or changes the procedure must be repeated 3 If monitoring point field strengths or antenna monitor parameters exceed allowable limits following the replacement or modification of that portion of the sampling system above the base of the towers a partial proof of performance shall be executed in accordance with 73 154 The partial proof of performance shall be accompanied by common point impedance measurements made in accordance with 73 54 4 Request for modification of license shall be submitted to the FCC in Washington DC within 30 days of the date of sampling system modification or replacement Such request shall specify the transmitter plate voltage and plate current common point current base currents and their ratios antenna monitor phase and current indications and all other data obtained pursuant to this paragraph f If an existing sampling system is found to be patently of marginal construction or where the performance of a directional antenna is found to be unsatisfactory and this deficiency reasonably may be attributed in whole or in part to inadequacies in the antenna monitoring system the FCC may require the reconstruction of the sampling system in accordance with requirements | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
specified above 41 FR 7405 Feb 18 1976 Editorial Note For FEDERAL REGISTER citations affecting 73 68 see the List of CFR Sections Affected which appears in the Finding Aids section of the printed volume and at www govinfo gov 73 69 Antenna monitors a Each station using a directional antenna must have in operation at the transmitter site an FCC authorized antenna monitor b In the event that the antenna monitor sampling system is temporarily out of service for repair or replacement the station may be operated pending completion of repairs or replacement for a period not exceeding 120 days without further authority from the FCC if all other operating parameters and the field monitoring point values are within the limits specified on the station authorization c If conditions beyond the control of the licensee prevent the restoration of the monitor to service within the allowed period an informal letter request in accordance with 73 3549 of the Commission s rules must be filed with the FCC Attention Audio Division Media Bureau in Washington DC for such additional time as may be required to complete repairs of the defective instrument 47 CFR 73 69 c enhanced display page 37 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 69 d Radio Broadcast Services d If an authorized antenna monitor is replaced by another antenna monitor the following procedure shall be followed 1 Temporary authority shall be requested and obtained from the Commission in Washington to operate with parameters at variance with licensed values pending issuance of a modified license specifying new parameters 2 Immediately before the replacement of the antenna monitor after a verification that all monitoring point values and the common point current reading are within the limits or tolerances | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
specified in the rules the following indications must be recorded for each radiation pattern Final plate current and plate voltage common point current antenna monitor phase and current indications and the field strength at each monitoring point 3 With the new monitor substituted for the old all indications specified in paragraph d 2 of this section again must be read If no change has occurred in the indication for any parameter other than the indications of the antenna monitor the new antenna monitor indications must be deemed to be those reflecting correct array adjustments 4 If it cannot be established by the observations required in paragraph d 2 of this section that the common point current reading and the monitoring point values are within the tolerances or limits prescribed by the rules and the instrument of authorization or if the substitution of the new antenna monitor for the old results in changes in these parameters a partial proof of performance shall be executed and analyzed in accordance with 73 154 5 An informal letter request for modification of license shall be submitted to the FCC Attention Audio Division Media Bureau in Washington DC within 30 days of the date of monitor replacement Such request shall specify the make type and serial number of the replacement monitor phase and sample current indications and other data obtained pursuant to this paragraph d e The antenna monitor must be calibrated according to the manufacturer s instructions as often as necessary to ensure its proper operation 38 FR 1918 Jan 19 1973 Editorial Note For FEDERAL REGISTER citations affecting 73 69 see the List of CFR Sections Affected which appears in the Finding Aids section of the printed volume and at www govinfo gov 73 72 Operating during the experimental period a An AM | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
station may operate during the experimental period the time between midnight and sunrise local time on its assigned frequency and with its authorized power for the routine testing and maintenance of its transmitting system and for conducting experimentation under an experimental authorization provided no interference is caused to other stations maintaining a regular operating schedule within such period b No station licensed for daytime or specified hours of operation may broadcast any regular or scheduled program during this period c The licensee of an AM station shall operate or refrain from operating its station during the experimental period as directed by the FCC to facilitate frequency measurements or for the determination of interference 47 CFR 73 72 c enhanced display page 38 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 88 Radio Broadcast Services 43 FR 32780 July 28 1978 as amended at 56 FR 64859 Dec 12 1991 73 88 Blanketing interference The licensee of each broadcast station is required to satisfy all reasonable complaints of blanketing interference within the 1 V m contour Note For more detailed instructions concerning operational responsibilities of licensees and permittees under this section see 73 318 b c and d 28 FR 13574 Dec 14 1963 as amended at 56 FR 64859 Dec 12 1991 73 99 Presunrise service authorization PSRA and postsunset service authorization PSSA a To provide maximum uniformity in early morning operation compatible with interference considerations and to provide for additional service during early evening hours for Class D stations provisions are made for presunrise service and postsunset service The permissible power for presunrise or postsunset service authorizations shall not exceed 500 watts or the authorized daytime or critical hours power whichever is less Calculation of the permissible power shall consider | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
only co channel stations for interference protection purposes b Presunrise service authorizations PSRA permit 1 Class D stations operating on Mexican Bahamian and Canadian priority Class A clear channels to commence PSRA operation at 6 a m local time and to continue such operation until the sunrise times specified in their basic instruments of authorization 2 Class D stations situated outside 0 5 mV m 50 skywave contours of co channel U S Class A stations to commence PSRA operation at 6 a m local time and to continue such operation until sunrise times specified in their basic instruments of authorization 3 Class D stations located within co channel 0 5 mV m 50 skywave contours of U S Class A stations to commence PSRA operation either at 6 a m local time or at sunrise at the nearest Class A station located east of the Class D station whichever is later and to continue such operation until the sunrise times specified in their basic instruments of authorization 4 Class B and Class D stations on regional channels to commence PSRA operation at 6 a m local time and to continue such operation until local sunrise times specified in their basic instruments of authorization c Extended Daylight Saving Time Pre Sunrise Authorizations 1 Between the first Sunday in April and the end of the month of April Class D stations will be permitted to conduct pre sunrise operation beginning at 6 a m local time with a maximum power of 500 watts not to exceed the station s regular daytime or critical hours power reduced as necessary to comply with the following requirements i Full protection is to be provided as specified in applicable international agreements ii Protection is to be provided to the 0 5 mV m groundwave signals | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
of co channel U S Class A stations protection to the 0 5 mV m 50 skywave contours of these stations is not required 47 CFR 73 99 c 1 ii enhanced display page 39 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 99 c 1 iii Radio Broadcast Services iii In determining the protection to be provided the effect of each interfering signal will be evaluated separately The presence of interference from other stations will not reduce or eliminate the required protection iv Notwithstanding the requirements of paragraph c 1 ii and iii of this section the stations will be permitted to operate with a minimum power of 10 watts unless a lower power is required by international agreement 2 The Commission will issue appropriate authorizations to Class D stations not previously eligible to operate during this period Class D stations authorized to operate during this presunrise period may continue to operate under their current authorization d Postsunset service authorizations PSSA permit 1 Class D stations located on Mexican Bahamian and Canadian priority Class A clear channels to commence PSSA operation at sunset times specified in their basic instruments of authorization and to continue for two hours after such specified times 2 Class D stations situated outside 0 5 mV m 50 skywave contours of co channel U S Class A stations to commence PSSA operations at sunset times specified in their basic instruments of authorization and to continue for two hours after such specified times 3 Class D stations located within co channel 0 5 mV m 50 skywave contours of U S Class A stations to commence PSSA operation at sunset times specified in their basic instruments of authorization and to continue such operation until two hours past | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
such specified times or until sunset at the nearest Class A station located west of the Class D station whichever is earlier Class D stations located west of the Class A station do not qualify for PSSA operation 4 Class D stations on regional channels to commence PSSA operation at sunset times specified on their basic instruments of authorization and to continue such operation until two hours past such specified times e Procedural Matters 1 Applications for PSRA and PSSA operation are not required Instead the FCC will calculate the periods of such operation and the power to be used pursuant to the provisions of this section and the protection requirements contained in applicable international agreements Licensees will be notified of permissible power and times of operation Presunrise and Postsunset service authority permits operation on a secondary basis and does not confer license rights No request for such authority need be filed However stations intending to operate PSRA or PSSA shall submit by letter signed as specified in 73 3513 the following information i Licensee name station call letters and station location ii Indication as to whether PSRA operation PSSA operation or both is intended by the station iii A description of the method whereby any necessary power reduction will be achieved 2 Upon submission of the required information such operation may begin without further authority f Technical criteria Calculations to determine whether there is objectionable interference will be determined in accordance with the AM Broadcast Technical Standards 73 182 through 73 190 and applicable international agreements Calculations will be performed using daytime antenna systems or 47 CFR 73 99 f enhanced display page 40 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 99 f 1 Radio Broadcast Services critical hours | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
antenna systems when specified on the license In performing calculations to determine assigned power and times for commencement of PSRA and PSSA operation the following standards and criteria will be used 1 Class D stations operating in accordance with paragraphs b 1 b 2 d 1 and d 2 of this section are required to protect the nighttime 0 5 mV m 50 skywave contours of co channel Class A stations Where a 0 5 mV m 50 skywave signal from the Class A station is not produced the 0 5 mV m groundwave contour shall be protected 2 Class D stations are required to fully protect foreign Class B and Class C stations when operating PSRA and PSSA Class D stations operating PSSA are required to fully protect U S Class B stations For purposes of determining protection the nighttime RSS limit will be used in the determination of maximum permissible power 3 Class D stations operating in accordance with paragraphs d 2 and d 3 of this section are required to restrict maximum 10 skywave radiation at any point on the daytime 0 1 mV m groundwave contour of a co channel Class A station to 25 µV m The location of the 0 1 mV m contour of the Class A station will be determined by use of Figure M3 Estimated Ground Conductivity in the United States When the 0 1 mV m contour extends beyond the national boundary the international boundary shall be considered the 0 1 mV m contour 4 Class B and Class D stations on regional channels operating PSRA and PSSA Class D only are required to provide full protection to co channel foreign Class B and Class C stations 5 Class D stations on regional channels operating PSSA beyond 6 p m | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
local time are required to fully protect U S Class B stations 6 The protection that Class D stations on regional channels are required to provide when operating PSSA until 6 p m local time is as follows i For the first half hour of PSSA operation protection will be calculated at sunset plus 30 minutes at the site of the Class D station ii For the second half hour of PSSA operation protection will be calculated at sunset plus one hour at the site of the Class D station iii For the second hour of PSSA operation protection will be calculated at sunset plus two hours at the site of the Class D station iv Minimum powers during the period until 6 p m local time shall be permitted as follows Calculated power Adjusted minimum power From 1 to 45 watts 50 watts Above 45 to 70 watts 75 watts Above 70 to 100 watts 100 watts 7 For protection purposes the nighttime 25 RSS limit will be used in the determination of maximum permissible power g Calculations made under paragraph d of this section may not take outstanding PSRA or PSSA operations into account nor will the grant of a PSRA or PSSA confer any degree of interference protection on the holder thereof 47 CFR 73 99 g enhanced display page 41 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 99 h Radio Broadcast Services h Operation under a PSRA or PSSA is not mandatory and will not be included in determining compliance with the requirements of 73 1740 To the extent actually undertaken however presunrise operation will be considered by the FCC in determining overall compliance with past programming representations and station policy concerning commercial matter i The | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
PSRA or PSSA is secondary to the basic instrument of authorization with which it is to be associated The PSRA or PSSA may be suspended modified or withdrawn by the FCC without prior notice or right to hearing if necessary to resolve interference conflicts to implement agreements with foreign governments or in other circumstances warranting such action Moreover the PSRA or PSSA does not extend beyond the term of the basic authorization j The Commission will periodically recalculate maximum permissible power and times for commencing PSRA and PSSA for each Class D station operating in accordance with paragraph c of this section The Commission will calculate the maximum power at which each individual station may conduct presunrise operations during extended daylight saving time and shall issue conforming authorizations These original notifications and subsequent notifications should be associated with the station s authorization Upon notification of new power and time of commencing operation affected stations shall make necessary adjustments within 30 days k A PSRA and PSSA does not require compliance with 73 45 73 182 and 73 1560 where the operation might otherwise be considered as technically substandard Further the requirements of paragraphs a 5 b 2 c 2 and d 2 of 73 1215 concerning the scale ranges of transmission system indicating instruments are waived for PSRA and PSSA operation except for the radio frequency ammeters used in determining antenna input power 1 A station having an antenna monitor incapable of functioning at the authorized PSRA and PSSA power when using a directional antenna shall take the monitor reading using an unmodulated carrier at the authorized daytime power immediately prior to commencing PSRA or PSSA operations Special conditions as the FCC may deem appropriate may be included for PSRA or PSSA to insure operation of the transmitter and associated | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
equipment in accordance with all phases of good engineering practice 56 FR 64860 Dec 12 1991 57 FR 43290 Sept 18 1992 as amended at 58 FR 27950 May 12 1993 73 127 Use of multiplex transmission The licensee of an AM broadcast station may use its AM carrier to transmit signals not audible on ordinary consumer receivers for both broadcast and non broadcast purposes subject to the following requirements a Such use does not disrupt or degrade the station s own programs or the programs of other broadcast stations b AM carrier services that are common carrier in nature are subject to common carrier regulation Licensees operating such services are required to apply to the FCC for the appropriate authorization and to comply with all policies and rules applicable to the service Responsibility for making the initial determinations of whether a particular activity is common carriage rests with the AM station licensee Initial determinations by licensees are subject to FCC examination and may be reviewed at the FCC s discretion AM carrier services that are private carrier in nature must notify the Licensing Division of the Private Radio Bureau at Gettysburg Pennsylvania 17325 by letter prior to initiating service certifying compliance with 47 CFR parts 90 and 94 47 CFR 73 127 b enhanced display page 42 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 127 c Radio Broadcast Services c AM carrier services are of a secondary nature under the authority of the AM station authorization and the authority to provide such communications services may not be retained or transferred in any manner separate from the station s authorization The grant or renewal of an AM station permit or license is not furthered or promoted by proposed or past | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
service The permittee or licensee must establish that the broadcast operation is in the public interest wholly apart from the subsidiary communications services provided d The station identification delayed recording and sponsor identification announcements required by 73 1201 73 1208 and 73 1212 are not applicable to leased communications services transmitted via services that are not of a general broadcast program nature e The licensee or permittee must retain control over all material transmitted in a broadcast mode via the station s facilities with the right to reject any material that it deems inappropriate or undesirable f Installation of the multiplex transmitting equipment must conform with the requirements of 73 1690 e 47 FR 25345 June 11 1982 as amended at 49 FR 34015 Aug 28 1984 51 FR 41629 Nov 18 1986 51 FR 44478 Dec 10 1986 73 128 AM stereophonic broadcasting a An Am broadcast station may without specific authority from the FCC transmit stereophonic programs upon installation of type accepted stereophonic transmitting equipment and the necessary measuring equipment to determine that the stereophonic transmissions conform to the modulation characteristics specified in paragraphs b and c of this section Stations transmitting stereophonic programs prior to March 21 1994 may continue to do so until March 21 1995 as long as they continue to comply with the rules in effect prior to March 21 1994 b The following limitations on the transmitted wave must be met to insure compliance with the occupied bandwidth limitations compatibility with AM receivers using envelope detectors and any applicable international agreements to which the FCC is a party 1 The transmitted wave must meet the occupied bandwidth specifications of 73 44 under all possible conditions of program modulation Compliance with requirement shall be demonstrated either by the following specific modulation tests or other | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
documented test procedures that are to be fully described in the application for type acceptance and the transmitting equipment instruction manual See 2 983 d 8 and j i Main channel L R under all conditions of amplitude modulations for the stereophonic system but not exceeding amplitude modulation on negative peaks of 100 ii Stereophonic L R modulated with audio tones of the same amplitude at the transmitter input terminals as in paragraph b i of this section but with the phase of either the L or R channel reversed iii Left and Right Channel only under all conditions of modulation for the stereophonic system in use but not exceeding amplitude modulation on negative peaks of 100 c Effective on December 20 1994 stereophonic transmissions shall conform to the following additional modulation characteristics 47 CFR 73 128 c enhanced display page 43 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 128 c 1 Radio Broadcast Services 1 The audio response of the main L R channel shall conform to the requirements of the ANSI EIA 549 1988 NRSC 1 AM Preemphasis Deemphasis and Broadcast Transmission Bandwidth Specifications NRSC 1 2 The left and right channel audio signals shall conform to frequency response limitations dictated by ANSI EIA 549 1988 3 The stereophonic difference L R information shall be transmitted by varying the phase of the carrier in accordance with the following relationship where L t audio signal left channel R t audio signal right channel m modulation factor and mpeak L t R t 1 for 100 amplitude modulation mpeak L t R t 1 for 100 phase modulation 4 The carrier phase shall advance in a positive direction when a left channel signal causes the transmitter envelope to be modulated | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
in a positive direction The carrier phase shall likewise retard negative phase change when a right channel signal causes the transmitter envelope to be modulated in a positive direction The phase modulation shall be symmetrical for the condition of difference L R channel information sent without the presence of envelope modulation 5 Maximum angular modulation which occurs on negative peaks of the left or right channel with no signal present on the opposite channel L t 0 75 R t 0 or R t 0 75 L t 0 shall not exceed 1 25 radians 6 A peak phase modulation of 0 785 radians under the condition of difference L R channel modulation and the absence of envelope L R modulation and pilot signal shall represent 100 modulation of the difference channel 7 The composite signal shall contain a pilot tone for indication of the presence of stereophonic information The pilot tone shall consist of a 25 Hz tone with 3 or less total harmonic distortion and a frequency tolerance of 0 1 H2 which modulates the carrier phase 0 05 radians peak corresponding to 5 L R modulation when no other modulation is present The injection level shall be 5 with a tolerance of 1 1 8 The composite signal shall be described by the following expression 47 CFR 73 128 c 8 enhanced display page 44 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 128 c 8 Radio Broadcast Services where A the unmodulated carrier voltage m the modulation index Csn the magnitude of the nth term of the sum signal Cdn the magnitude of the nth term of the difference signal ωsn the nth order angular velocity of the sum signal ωdn the nth order angular velocity of | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
the difference signal ωc the angular velocity of the carrier Asn and Bsn are the nth sine and cosine coefficients of Csn 47 CFR 73 128 c 8 enhanced display page 45 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 132 Radio Broadcast Services Adn and Bdn are the nth sine and cosine coefficients of Cdn 58 FR 66301 Dec 20 1993 73 132 Territorial exclusivity No licensee of an AM broadcast station shall have any arrangement with a network organization which prevents or hinders another station serving substantially the same area from broadcasting the network s programs not taken by the former station or which prevents or hinders another station serving a substantially different area from broadcasting any program of the network organization Provided however That this section does not prohibit arrangements under which the station is granted first call within its primary service area upon the network s programs The term network organization means any organization originating program material with or without commercial messages and furnishing the same to stations interconnected so as to permit simultaneous broadcast by all or some of them However arrangements involving only stations under common ownership or only the rebroadcast by one station or programming from another with no compensation other than a lump sum payment by the station rebroadcasting are not considered arrangements with a network organization The term arrangement means any contract arrangement or understanding expressed or implied 42 FR 16422 Mar 28 1977 73 150 Directional antenna systems a For each station employing a directional antenna all determinations of service provided and interference caused shall be based on the inverse distance fields of the standard radiation pattern for that station As applied to nighttime operation the term standard radiation pattern shall | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
include the radiation pattern in the horizontal plane and radiation patterns at angles above this plane 1 Parties submitting directional antenna patterns pursuant to this section and 73 152 Modified standard pattern must submit patterns which are tabulated and plotted in units of millivolts per meter at 1 kilometer Note Applications for new stations and for changes both minor and major in existing stations must use a standard pattern b The following data shall be submitted with an application for authority to install a directional antenna 1 The standard radiation pattern for the proposed antenna in the horizontal plane and where pertinent tabulated values for the azimuthal radiation patterns for angles of elevation up to and including 60 degrees with a separate section for each increment of 5 degrees i The standard radiation pattern shall be based on the theoretical radiation pattern The theoretical radiation pattern shall be calculated in accordance with the following mathematical expression where 47 CFR 73 150 b 1 i enhanced display page 46 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 150 b 1 i Radio Broadcast Services E φ θ th Represents the theoretical inverse distance fields at one kilometer for the given azimuth and elevation k Represents the multiplying constant which determines the basic pattern size It shall be chosen so that the effective field RMS of the theoretical pattern in the horizontal plane shall be no greater than the value computed on the assumption that nominal station power see 73 14 is delivered to the directional array and that a lumped loss resistance of one ohm exists at the current loop of each element of the array or at the base of each element of electrical height lower than 0 25 wavelength and | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
no less than the value required by 73 189 b 2 of this part for a station of the class and nominal power for which the pattern is designed n Represents the number of elements towers in the directional array i Represents the ith element in the array Fi Represents the field ratio of the ith element in the array θ Represents the vertical elevation angle measured from the horizontal plane fi θ represents the vertical plane radiation characteristic of the ith antenna This value depends on the tower height as well as whether the tower is top loaded or sectionalized The various formulas for computing fi θ are given in 73 160 Si Represents the electrical spacing of the ith tower from the reference point φi Represents the orientation with respect to true north of the ith tower φ Represents the azimuth with respect to true north ψ Represents the electrical phase angle of the current in the ith tower i The standard radiation pattern shall be constructed in accordance with the following mathematical expression where E φ θ std represents the inverse distance fields at one kilometer which are produced by the directional antenna in the horizontal and vertical planes E φ θ th represents the theoretical inverse distance fields at one kilometer as computed in accordance with Eq 1 above Q is the greater of the following two quantities 0 025g θ Erss or 10 0g θ PkW where 47 CFR 73 150 b 1 i enhanced display page 47 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 150 b 1 ii Radio Broadcast Services g θ is the vertical plane distribution factor f θ for the shortest element in the array see Eq 2 above also see | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
73 190 Figure 5 If the shortest element has an electrical height in excess of 0 5 wavelength g θ shall be computed as follows Erss is the root sum square of the amplitudes of the inverse fields of the elements of the array in the horizontal plane as used in the expression for E φ θ th see Eq 1 above and is computed as follows PkW is the nominal station power expressed in kilowatts see 73 14 If the nominal power is less than one kilowatt PkW 1 ii Where the orthogonal addition of the factor Q to E φ θ th results in a standard pattern whose minimum fields are lower than those found necessary or desirable these fields may be increased by appropriate adjustment of the parameters of E φ θ th 2 All patterns shall be computed for integral multiples of five degrees beginning with zero degrees representing true north and shall be plotted to the largest scale possible on unglazed letter size paper main engraving approximately 7 10 using only scale divisions and subdivisions of 1 2 2 5 or 5 times 10nth The horizontal plane pattern shall be plotted on polar coordinate paper with the zero degree point corresponding to true north Patterns for elevation angles above the horizontal plane may be plotted in polar or rectangular coordinates with the pattern for each angle of elevation on a separate page Rectangular plots shall begin and end at true north with all azimuths labelled in increments of not less than 20 degrees If a rectangular plot is used the ordinate showing the scale for radiation may be logarithmic Such patterns for elevation angles above the horizontal plane need be submitted only upon specific request by Commission staff Minor lobe and null detail occurring between | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
successive patterns for specific angles of elevation need not be submitted Values of field strength on any pattern less than ten percent of the maximum field strength plotted on that pattern shall be shown on an enlarged scale Rectangular plots with a logarithmic ordinate need not utilize an expanded scale unless necessary to show clearly the minor lobe and null detail 3 The effective RMS field strength in the horizontal plane of E φ θ std E φ θ th and the root sum square RSS value of the inverse distance fields of the array elements at 1 kilometer derived from the equation for E φ θ th These values shall be tabulated on the page on which the horizontal plane pattern is plotted which shall be specifically labelled as the Standard Horizontal Plane Pattern 4 Physical description of the array showing i Number of elements ii Type of each element i e guyed or self supporting uniform cross section or tapered specifying base dimensions grounded or insulated etc iii Details of top loading or sectionalizing if any 47 CFR 73 150 b 4 iii enhanced display page 48 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 150 b 4 iv Radio Broadcast Services iv Height of radiating portion of each element in feet height above base insulator or base if grounded v Overall height of each element above ground vi Sketch of antenna site indicating its dimensions the location of the antenna elements thereon their spacing from each other and their orientation with respect to each other and to true north the number and length of the radials in the ground system about each element the dimensions of ground screens if any and bonding between towers and between radial systems | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
5 Electrical description of the array showing i Relative amplitudes of the fields of the array elements ii Relative time phasing of the fields of the array elements in degrees leading or lagging iii Space phasing between elements in degrees iv Where waiver of the content of this section is requested or upon request of the Commission staff all assumptions made and the basis therefor particularly with respect to the electrical height of the elements current distribution along elements efficiency of each element and ground conductivity v Where waiver of the content of this section is requested or upon request of the Commission staff those formulas used for computing E φ θ th and E φ θ std Complete tabulation of final computed data used in plotting patterns including data for the determination of the RMS value of the pattern and the RSS field of the array 6 The values used in specifying the parameters which describe the array must be specified to no greater precision than can be achieved with available monitoring equipment Use of greater precision raises a rebuttable presumption of instability of the array Following are acceptable values of precision greater precision may be used only upon showing that the monitoring equipment to be installed gives accurate readings with the specified precision i Field Ratio 3 significant figures ii Phasing to the nearest 0 1 degree iii Orientation with respect to a common point in the array or with respect to another tower to the nearest 0 1 degree iv Spacing with respect to a common point in the array or with respect to another tower to the nearest 0 1 degree v Electrical Height for all parameters listed in Section 73 160 to the nearest 0 1 degree vi Theoretical RMS to determine pattern size 4 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
significant figures vii Additional requirements relating to modified standard patterns appear in 73 152 c 3 and c 4 7 Any additional information required by the application form 47 CFR 73 150 b 7 enhanced display page 49 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 150 c Radio Broadcast Services c Sample calculations for the theoretical and standard radiation follow Assume a five kilowatt nominal power station with a theoretical RMS of 685 mV m at one kilometer Assume that it is an in line array consisting of three towers Assume the following parameters for the towers Tower Field ratio Relative phasing Relative spacing Relative orientation 1 1 0 128 5 0 0 0 0 2 1 89 0 0 110 0 285 0 3 1 0 128 5 220 0 285 0 Assume that tower 1 is a typical tower with an electrical height of 120 degrees Assume that tower 2 is top loaded in accordance with the method described in 73 160 b 2 where A is 120 electrical degrees and B is 20 electrical degrees Assume that tower 3 is sectionalized in accordance with the method described in 73 160 b 3 where A is 120 electrical degrees B is 20 electrical degrees C is 220 electrical degrees and D is 15 electrical degrees The multiplying constant will be 323 6 Following is a tabulation of part of the theoretical pattern Azimuth 0 30 60 Vertical angle 0 15 98 62 49 68 20 105 1225 30 819 79 234 54 235 0 43 18 46 34 56 247 82 62 51 52 26 38 If we further assume that the station has a standard pattern we find that Q for θ 0 is 22 36 Following | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
is a tabulation of part of the standard pattern Azimuth 0 30 60 Vertical angle 0 28 86 68 05 72 06 105 1286 78 860 97 246 41 235 23 48 26 50 37 18 247 89 87 57 03 28 87 The RMS of the standard pattern in the horizontal plane is 719 63 mV m at one kilometer 36 FR 919 Jan 20 1971 as amended at 37 FR 529 Jan 13 1972 41 FR 24134 June 15 1976 46 FR 11991 Feb 12 1981 48 FR 24384 June 1 1983 51 FR 2707 Jan 21 1986 52 FR 36877 Oct 1 1987 56 FR 64861 Dec 12 1991 57 FR 43290 Sept 18 1992 73 151 Field strength measurements to establish performance of directional antennas The performance of a directional antenna may be verified either by field strength measurement or by computer modeling and sampling system verification 47 CFR 73 151 enhanced display page 50 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 151 a Radio Broadcast Services a In addition to the information required by the license application form the following showing must be submitted to establish for each mode of directional operation that the effective measured field strength RMS at 1 kilometer km is not less than 85 percent of the effective measured field strength RMS specified for the standard radiation pattern or less than that specified in 73 189 b for the class of station involved whichever is the higher value and that the measured field strength at 1 km in any direction does not exceed the field shown in that direction on the standard radiation pattern for that mode of directional operation 1 A tabulation of inverse field strengths in the horizontal plane | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
at 1 km as determined from field strength measurements taken and analyzed in accordance with 73 186 and a statement of the effective measured field strength RMS Measurements shall be made in the following directions i Those specified in the instrument of authorization ii In major lobes Generally one radial is sufficient to establish a major lobe however additional radials may be required iii Along additional radials to establish the shape of the pattern In the case of a relatively simple directional antenna pattern a total of six radials is sufficient If two radials would be more than 90 apart then an additional radial must be specified within that arc When more complicated patterns are involved that is patterns having several or sharp lobes or nulls measurements shall be taken along as many as 12 radials to definitely establish the pattern s Pattern symmetry may be assumed for complex patterns which might otherwise require measurements on more than 12 radials 2 A tabulation of i The phase difference of the current in each element with respect to the reference element and whether the current leads or lags the current in the reference element as indicated by the station s antenna monitor ii The ratio of the amplitude of the radio frequency current in each element to the current in the reference element as indicated on the station s antenna monitor 3 A monitoring point shall be established on each radial for which the construction permit specifies a limit The following information shall be supplied for each monitoring point i Measured field strength ii An accurate and detailed description of each monitoring point The description may include but shall not be limited to geographic coordinates determined with a Global Positioning System receiver iii Clear photographs taken with the field strength meter | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
in its measuring position and with the camera so located that its field of view takes in as many pertinent landmarks as possible b For stations authorized to operate with simple directional antenna systems e g two towers in the 1605 1705 kHz band the measurements to support pattern RMS compliance referred to in paragraphs a 1 ii and a 1 iii of this section are not required In such cases measured radials are required only in the direction of short spaced allotments or in directions specifically identified by the Commission c Computer modeling and sample system verification of modeled parameters to establish operation of a directional antenna consistent with the theoretical pattern Each element of the directional array shall be modeled by use of a method of moments computer program using the physical characteristics of each 47 CFR 73 151 c enhanced display page 51 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 151 c 1 Radio Broadcast Services element to establish a model that does not violate any of the internal constraints of the computer program Only arrays consisting of series fed elements may have their performance verified by computer modeling and sample system verification 1 A matrix of impedance measurements at the base and or feed point of each element in the array with all other elements shorted and or open circuited at their respective measurement locations shall be made The physical model of the individual antenna elements used in the computer program may be varied to match the measured impedance matrix but the actual spacings and orientations of the array elements must be used Towers may be modeled using individual vertical wires to represent them or with multiple wires representing their leg and cross member sections The | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
resulting model description consisting of the length radius and number of segments of each wire for arrays using vertical wire sections to represent the towers or the length end point coordinates and radius of each wire used to represent leg and cross member sections for arrays using detailed tower structure representations as well as the assumed input feed and base region stray reactances shall be used to generate the drive impedances and sample system parameter values for the operating directional antenna pattern parameters i For arrays using vertical wires to represent each tower the radii of cylinders shall be no less than 80 percent and no more than 150 percent of the radius of a circle with a circumference equal to the sum of the widths of the tower sides ii For arrays using multiple wires to represent leg and cross member sections the individual legs of the tower may be modeled at their actual diameters with appropriate interconnecting segments representing cross members at regular intervals iii No less than one segment for each 10 electrical degrees of the tower s physical height shall be used for each element in the array iv Base calculations shall be made for a reference point at ground level or within one electrical degree elevation of the actual feed point v For uniform cross section towers represented by vertical wires each wire used for a given tower shall be between 75 to 125 percent of the physical length represented vi For self supporting towers stepped radius wire sections may be employed to simulate the physical tower s taper or the tower may be modeled with individual wire sections representing the legs and cross members vii The lumped series inductance of the feed system between the output port of each antenna tuning unit and the | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
associated tower shall be no greater than 10 µH unless a measured value from the measurement point to the tower base with its insulator short circuited is used viii The shunt capacitance used to model the base region effects shall be no greater than 250 pF unless the measured or manufacturer s stated capacitance for each device other than the base insulator is used The total capacitance of such devices shall be limited such that in no case will their total capacitive reactance be less than five times the magnitude of the tower base operating impedance without their effects being considered This five times requirement only applies when the total capacitance used to model base region effects exceeds 250 pF and when base current sampling is used 47 CFR 73 151 c 1 viii enhanced display page 52 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 151 c 1 ix Radio Broadcast Services ix The orientation and distances among the individual antenna towers in the array shall be confirmed by a post construction certification by a land surveyor or where permitted by local regulation by an engineer licensed or registered in the state or territory where the antenna system is located Stations submitting a moment method proof for a pattern using towers that are part of an authorized AM array are exempt from the requirement to submit a surveyor s certification provided that the tower geometry of the array is not being modified and that no new towers are being added to the array x An AM station that verified the performance of its directional antenna system using computer modeling and sampling system verification under this rule section that makes modifications to tower or system components above the base insulator shall | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
follow the procedures set forth in section 1 30003 b 2 of this chapter 2 i The computer model once verified by comparison with the measured base impedance matrix data shall be used to determine the appropriate antenna monitor parameters The moment method modeled parameters shall be established by using the verified moment method model to produce tower current distributions that when numerically integrated and normalized to the reference tower are identical to the specified field parameters of the theoretical directional antenna pattern The samples used to drive the antenna monitor may be current transformers or voltage sampling devices at the outputs of the antenna matching networks or sampling loops located on the towers If sample loops are used they shall be located at the elevation where the current in the tower would be at a minimum if the tower were detuned in the horizontal plane as determined by the moment method model parameters used to determine the antenna monitor parameters Sample loops may be employed only when the towers are identical in cross sectional structure including both leg and cross member characteristics if the towers are of unequal height the sample loops shall be mounted identically with respect to tower cross members at the appropriate elevations above the base insulator If the tower height used in the model is other than the physical height of the tower the sampling loop shall be located at a height that is the same fraction of the total tower height as the minimum in tower current with the tower detuned in the model Sample lines from the sensing element to the antenna monitor must be equal in both length within one electrical degree and characteristic impedance within two ohms as established by impedance measurements including at the open circuit resonant frequency closest to | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
carrier frequency to establish length at frequencies corresponding to odd multiples of 1 8 wavelength immediately above and below the open circuit resonant frequency closest to carrier frequency while open circuited to establish characteristic impedance and at carrier frequency or if necessary at nearby frequencies where the magnitude of the measured impedance is no greater than 200 ohms with the sampling devices connected Samples may be obtained from current transformers at the output of the antenna coupling and matching equipment for base fed towers whose actual electrical height is 120 degrees or less or greater than 190 electrical degrees Samples may be obtained from base voltage sampling devices at the output of the antenna coupling and matching equipment for base fed towers whose actual electrical height is greater than 105 degrees Samples obtained from sample loops located as described above can be used for any height of tower For towers using base current or base voltage sampling derived at the output of the antenna coupling and matching equipment the sampling devices shall be disconnected and calibrated by measuring their outputs with a common reference signal a current through them or a voltage across them 47 CFR 73 151 c 2 i enhanced display page 53 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 151 c 2 ii Radio Broadcast Services as appropriate and the calibration must agree within the manufacturer s specifications A complete description of the sampling system including the results of the measurements described in this paragraph shall be submitted with the application for license ii Proper adjustment of an antenna pattern shall be determined by correlation between the measured antenna monitor sample indications and the parameters calculated by the method of moments program and by correlation between the | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
measured matrix impedances for each tower and those calculated by the method of moments program The antenna monitor sample indications must be initially adjusted to agree with the moment method model within 5 percent for the field ratio and 3 degrees in phase The measured matrix impedances must agree with the moment method model within 2 ohms and 4 percent for resistance and reactance 3 When the application for an initial license for a directional antenna system is submitted that is based on computer modeling and sample system verification reference field strength measurement locations shall be established in the directions of pattern minima and maxima On each radial corresponding to a pattern minimum or maximum there shall be at least three measurement locations The field strength shall be measured at each reference location at the time of the proof of performance The license application shall include the measured field strength values at each reference point along with a description of each measurement location including GPS coordinates and datum reference New reference field strength measurements are not required for subsequent license applications for the same directional antenna pattern and physical facilities 36 FR 919 Jan 20 1971 as amended at 42 FR 36828 July 18 1977 49 FR 23348 June 6 1984 50 FR 32416 Aug 12 1985 56 FR 64862 Dec 12 1991 63 FR 33876 June 22 1998 66 FR 20756 Apr 25 2001 73 FR 64561 Oct 30 2008 82 FR 51165 Nov 3 2017 73 152 Modification of directional antenna data a If after construction and final adjustment of a directional antenna a measured inverse distance field in any direction exceeds the field shown on the standard radiation pattern for the pertinent mode of directional operation an application shall be filed specifying a modified standard radiation pattern | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
and or such changes as may be required in operating parameters so that all measured effective fields will be contained within the modified standard radiation pattern Permittees may also file an application specifying a modified standard radiation pattern even when measured radiation has not exceeded the standard pattern in order to allow additional tolerance for monitoring point limits b If following a partial proof of performance a licensee discovers that radiation exceeds the standard pattern on one or more radials because of circumstances beyond the licensee s control a modified standard pattern may be requested The licensee shall submit concurrently Forms 301 AM and 302 AM Form 301 AM shall include an exhibit demonstrating that no interference would result from the augmentation Form 302 AM shall include the results of the partial proof along with full directional and nondirectional measurements on the radial s to be augmented including close in points and a determination of the inverse distance field in accordance with 73 186 c Normally a modified standard pattern is not acceptable at the initial construction permit stage before a proof of performance has been completed However in certain cases where it can be shown that modification is necessary a modified standard pattern will be acceptable at the initial construction permit stage Following is a non inclusive list of items to be considered in determining whether a modification is acceptable at the initial construction permit stage 47 CFR 73 152 c enhanced display page 54 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 152 c 1 Radio Broadcast Services 1 When the proposed pattern is essentially the same as an existing pattern at the same antenna site e g A DA D station proposing to become a DA 1 station | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
2 Excessive reradiating structures which should be shown on a plat of the antenna site and surrounding area 3 Other environmental factors they should be fully described 4 Judgment and experience of the engineer preparing the engineering portion of the application This must be supported with a full discussion of the pertinent factors d The following general principles shall govern the situations in paragraphs a b and c in this section 1 Where a measured field in any direction will exceed the authorized standard pattern the license application may specify the level at which the input power to the antenna shall be limited to maintain the measured field at a value not in excess of that shown on the standard pattern and shall specify the common point current corresponding to this power level This value of common point current will be specified on the license for that station 2 Where any excessive field does not result in objectionable interference to another station a modification of construction permit application may be submitted with a modified standard pattern encompassing all augmented fields The modified standard pattern shall supersede the previously submitted standard radiation pattern for that station in the pertinent mode of directional operation Following are the possible methods of creating a modified standard pattern i The modified pattern may be computed by making the entire pattern larger than the original pattern i e have a higher RMS value if the measured fields systematically exceed the confines of the original pattern The larger pattern shall be computed by using a larger multiplying constant k in the theoretical pattern equation Eq 1 in 73 150 b 1 ii Where the measured field exceeds the pattern in discrete directions but objectionable interference does not result the pattern may be expanded over sectors including these | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
directions When this augmentation is desired it shall be achieved by application of the following equation E φ θ aug E φ θ std 2 A g θ cos 180 DA S 2 where E φ θ std is the standard pattern field at some particular azimuth and elevation angle before augmentation computed pursuant to Eq 2 73 150 b 1 i E φ θ aug is the field in the direction specified above after augmentation A E φ O 2aug E φ O 2std in whichφ is the central azimuth of augmentation E φ O aug and E φ O std are the fields in the horizontal plane at the central azimuth of augmentation Note A must be positive except during the process of converting non standard patterns to standard patterns pursuant to the Report and Order in Docket No 21473 and in making minor changes to stations with patterns developed during the conversion However even when A is negative A cannot be so negative that E φ α aug is less than E φ θ th at any azimuth or vertical 47 CFR 73 152 d 2 ii enhanced display page 55 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 152 d 2 iii Radio Broadcast Services elevation angle g θ is defined in 73 150 b 1 i S is the angular range or span over which augmentation is applied The span is centered on the central azimuth of augmentation At the limits of the span the augmented pattern merges into the unaugmented pattern Spans may overlap DA is the absolute horizontal angle between the azimuth at which the augmented pattern value is being computed and the central azimuth of augmentation DA cannot exceed 1 2 S In | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
the case where there are spans which overlap the above formula shall be applied repeatedly once for each augmentation in ascending order of central azimuth of augmentation beginning with zero degrees representing true North Note that when spans overlap there will be in effect an augmentation of an augmentation And if the span of an earlier augmentation overlaps the central azimuth of a later augmentation the value of A for the later augmentation will be different than the value of A without the overlap of the earlier span iii A combination of paragraphs d 2 i and d 2 ii of this section with d 2 i being applied before d 2 ii is applied iv Where augmentation is allowable under the terms of this section the requested amount of augmentation shall be centered upon the measured radial and shall not exceed the following A The actual measured inverse distance field value where the radial does not involve a required monitoring point B 120 of the actual measured inverse field value where the radial has a monitoring point required by the instrument of authorization Whereas some pattern smoothing can be accommodated the extent of the requested span s shall be minimized and in no case shall a requested augmentation span extend to a radial azimuth for which the analyzed measurement data does not show a need for augmentation 3 A Modified Standard Pattern shall be specifically labeled as such and shall be plotted in accordance with the requirements of paragraph b 2 of 73 150 The effective RMS field strength in the horizontal plane of E φ α std E φ α th and the root sum square RSS value of the inverse fields of the array elements derived from the equation for E φ α th shall be tabulated | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
on the page on which the horizontal plane pattern is plotted Where sector augmentation has been employed in designing the modified pattern the direction of maximum augmentation i e the central azimuth of augmentation shall be indicated on the horizontal plane pattern for each augmented sector and the limits of each sector shall also be shown Field values within an augmented sector computed prior to augmentation shall be depicted by a broken line 4 There shall be submitted for each modified standard pattern complete tabulations of final computed data used in plotting the pattern In addition for each augmented sector the central azimuth of augmentation span and radiation at the central azimuth of augmentation E φ α aug shall be tabulated 47 CFR 73 152 d 4 enhanced display page 56 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 152 d 5 Radio Broadcast Services 5 The parameters used in computing the modified standard pattern shall be specified with realistic precision Following is a list of the maximum acceptable precision i Central Azimuth of Augmentation to the nearest 0 1 degree ii Span to the nearest 0 1 degree iii Radiation at Central Azimuth of Augmentation 4 significant figures e Sample calculations for a modified standard pattern follow First assume the existing standard pattern in 73 150 c Then assume the following augmentation parameters Augmentation number Central azimuth Span Radiation at central azimuth 1 110 40 1 300 2 240 50 52 3 250 10 130 Following is a tabulation of part of the modified standard pattern Azimuth 0 30 60 Vertical angle 0 28 86 68 05 72 06 105 1 299 42 872 14 254 21 235 39 00 35 74 38 71 247 100 47 66 69 32 | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
78 46 FR 11992 Feb 12 1981 as amended at 56 FR 64862 Dec 12 1991 66 FR 20756 Apr 25 2001 73 153 Field strength measurements in support of applications or evidence at hearings In the determination of interference groundwave field strength measurements will take precedence over theoretical values provided such measurements are properly taken and presented When measurements of groundwave signal strength are presented they shall be sufficiently complete in accordance with 73 186 to determine the field strength at 1 mile in the pertinent directions for that station The antenna resistance measurements required by 73 186 need not be taken or submitted 44 FR 36037 June 20 1979 as amended at 56 FR 64862 Dec 12 1991 73 154 AM directional antenna partial proof of performance measurements a A partial proof of performance consists of at least 8 field strength measurements made on each of the radials that includes a monitoring point b The measurements are to be made within 3 to 15 kilometers from the center of the antenna array When a monitoring point as designated on the station authorization lies on a particular radial one of the measurements must be made at that point One of the following methods shall be used for the partial proof 47 CFR 73 154 b enhanced display page 57 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 154 b 1 Radio Broadcast Services 1 Measurement points shall be selected from the points measured in latest full proof of performance provided that the points can be identified with reasonable certainty and that land development or other factors have not significantly altered propagation characteristics since the last full proof At each point the licensee shall measure directional field strength for comparison to | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
either the directional or the nondirectional field strength measured at that point in the last full proof 2 In the event that a meaningful comparison to full proof measurements cannot be made the licensee shall measure both directional and nondirectional field strength at eight points on each radial The points need not be limited to those measured in the last full proof of performance c The results of the measurements are to be analyzed as follows Either the arithmetic average or the logarithmic average of the ratios of the field strength at each measurement point to the corresponding field strength in the most recent complete proof of performance shall be used to establish the inverse distance fields The logarithmic average for each radial is the antilogarithm of the mean of the logarithms of the ratios of field strength new to old for each measurement location along a given radial When new nondirectional measurements are used as the reference as described in paragraph b 2 of this section either the arithmetic or logarithmic averages of directional to nondirectional field strength on each radial shall be used in conjunction with the measured nondirectional field from the last proof to establish the inverse distance field d The result of the most recent partial proof of performance measurements and analysis is to be retained in the station records available to the FCC upon request Maps showing new measurement points i e points not measured in the last full proof shall be associated with the partial proof in the station s records and shall be provided to the FCC upon request 66 FR 20756 Apr 25 2001 as amended at 82 FR 51165 Nov 3 2017 73 155 Directional antenna performance recertification A station licensed with a directional antenna pattern pursuant to a proof of | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
performance using moment method modeling and internal array parameters as described in 73 151 c shall recertify the performance of the antenna monitor sampling system only in the case of repair to or replacement of affected system components and then only as to the repaired or replaced system components Any recertification of repaired or replaced system components shall be performed in the same manner as an original certification of the affected system components under 73 151 c 2 i of this part The results of the recertification measurements shall be retained in the station s public inspection file 82 FR 51162 Nov 3 2017 73 157 Antenna testing during daytime a The licensee of a station using a directional antenna during daytime or nighttime hours may without further authority operate during daytime hours with the licensed nighttime directional facilities or with a nondirectional antenna when conducting monitoring point field strength measurements or antenna proof of performance measurements b Operation pursuant to this section is subject to the following conditions 1 No harmful interference will be caused to any other station 47 CFR 73 157 b 1 enhanced display page 58 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 157 b 2 Radio Broadcast Services 2 The FCC may notify the licensee to modify or cease such operation to resolve interference complaints or when such action may appear to be in the public interest convenience and necessity 3 Such operation shall be undertaken only for the purpose of taking monitoring point field strength measurements or antenna proof of performance measurements and shall be restricted to the minimum time required to accomplish the measurements 4 Operating power in the nondirectional mode shall be adjusted to the same power as was utilized for the | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
most recent nondirectional proof of performance covering the licensed facilities 50 FR 30947 July 31 1985 73 158 Directional antenna monitoring points a When a licensee of a station using a directional antenna system finds that a field monitoring point as specified on the station authorization is no longer accessible or is unsuitable because of nearby construction or other disturbances to the measured field an application to change the monitoring point location including FCC Form 302 AM is to be promptly submitted to the FCC in Washington DC 1 If the monitoring point has become inaccessible or otherwise unsuitable but there has been no significant construction or other change in the vicinity of the monitoring point which may affect field strength readings the licensee shall select a new monitoring point from the points measured in the last full proof of performance A recent field strength measurement at the new monitoring point shall also be provided 2 Alternatively if changes in the electromagnetic environment have affected field strength readings at the monitoring point the licensee shall submit the results of a partial proof of performance analyzed in accordance with 73 154 on the affected radial 3 The licensee shall submit an accurate written description of the new monitoring point in relation to nearby permanent landmarks 4 The licensee shall submit a photograph showing the new monitoring point in relation to nearby permanent landmarks that can be used in locating the point accurately at all times throughout the year Do not use seasonal or temporary features in either the written descriptions or photographs as landmarks for locating field points b When the description of the monitoring point as shown on the station license is no longer correct due to road or building construction or other changes the licensee must prepare and file | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
with the FCC in Washington DC a request for a corrected station license showing the new monitoring point description The request shall include the information specified in paragraphs a 3 and 4 of this section and a copy of the station s current license 66 FR 20757 Apr 25 2001 as amended at 84 FR 2758 Feb 8 2019 73 160 Vertical plane radiation characteristics f θ a The vertical plane radiation characteristics show the relative field being radiated at a given vertical angle with respect to the horizontal plane The vertical angle represented as θ is 0 degrees in the horizontal plane and 90 degrees when perpendicular to the horizontal plane The vertical plane radiation characteristic is referred to as f θ The generic formula for f θ is 47 CFR 73 160 a enhanced display page 59 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 160 b Radio Broadcast Services f θ E θ E O where E θ is the radiation from the tower at angle θ E O is the radiation from the tower in the horizontal plane b Listed below are formulas for f θ for several common towers 1 For a typical tower which is not top loaded or sectionalized the following formula shall be used where G is the electrical height of the tower not including the base insulator and pier In the case of a folded unipole tower the entire radiating structure s electrical height is used 2 For a top loaded tower the following formula shall be used where A is the physical height of the tower in electrical degrees and B is the difference in electrical degrees between the apparent electrical height G based on current distribution and the actual physical | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
height G is the apparent electrical height the sum of A and B A B See Figure 1 of this section 47 CFR 73 160 b 2 enhanced display page 60 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 160 b 2 Radio Broadcast Services 47 CFR 73 160 b 2 enhanced display page 61 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 160 b 3 Radio Broadcast Services 3 For a sectionalized tower the following formula shall be used where A is the physical height in electrical degrees of the lower section of the tower B is the difference between the apparent electrical height based on current distribution of the lower section of the tower and the physical height of the lower section of the tower C is the physical height of the entire tower in electrical degrees D is the difference between the apparent electrical height of the tower based on current distribution of the upper section and the physical height of the entire tower D will be zero if the sectionalized tower is not top loaded G is the sum of A and B A B H is the sum of C and D C D Δ is the difference between H and A H A See Figure 2 of this section 47 CFR 73 160 b 3 enhanced display page 62 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 160 b 3 Radio Broadcast Services 47 CFR 73 160 b 3 enhanced display page 63 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 160 c Radio Broadcast Services c One | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
of the above f θ formulas must be used in computing radiation in the vertical plane unless the applicant submits a special formula for a particular type of antenna If a special formula is submitted it must be accompanied by a complete derivation and sample calculations Submission of values for f θ only in a tabular or graphical format i e without a formula is not acceptable d Following are sample calculations The number of significant figures shown here should not be interpreted as a limitation on the number of significant figures used in actual calculations 1 For a typical tower as described in paragraph b 1 of this section assume that G 120 electrical degrees θ f θ 0 1 0000 30 0 7698 60 0 3458 2 For a top loaded tower as described in paragraph b 2 of this section assume A 120 electrical degrees B 20 electrical degrees and G 140 electrical degrees 120 20 θ f θ 0 1 0000 30 0 7364 60 0 2960 3 For a sectionalized tower as described in paragraph b 3 of this section assume A 120 electrical degrees B 20 electrical degrees C 220 electrical degrees D 15 electrical degrees G 140 electrical degrees 120 20 H 235 electrical degrees 220 15 and Δ 115 electrical degrees 235 120 θ f θ 0 1 0000 30 0 5930 60 0 1423 46 FR 11993 Feb 12 1981 73 182 Engineering standards of allocation a Sections 73 21 to 73 37 inclusive govern allocation of facilities in the AM broadcast band 535 1705 kHz 73 21 establishes three classes of channels in this band namely clear regional and local The classes and power of AM broadcast stations which will be assigned to the various channels are set forth in | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
73 21 The classifications of the AM broadcast stations are as follows 1 Class A stations operate on clear channels with powers no less than 10kW nor greater than 50 kW These stations are designed to render primary and secondary service over an extended area with their primary services areas protected from objectionable interference from other stations on the same and adjacent channels Their secondary service areas are protected from objectionable 47 CFR 73 182 a 1 enhanced display page 64 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 182 a 1 i Radio Broadcast Services interference from co channel stations For purposes of protection Class A stations may be divided into two groups those located in any of the contiguous 48 States and those located in Alaska in accordance with 73 25 i The mainland U S Class A stations are those assigned to the channels allocated by 73 25 The power of these stations shall be 50 kW The Class A stations in this group are afforded protection as follows A Daytime To the 0 1 mV m groundwave contour from stations on the same channel and to the 0 5 mV m groundwave contour from stations on adjacent channels B Nighttime To the 0 5 mV m 50 skywave contour from stations on the same channels ii Class A stations in Alaska operate on the channels allocated by 73 25 with a minimum power of 10 kW a maximum power of 50 kW and an antenna efficiency of 215 mV m kW at 1 kilometer Stations operating on these channels in Alaska which have not been designated as Class A stations in response to licensee request will continue to be considered as Class B stations During daytime hours | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
a Class A station in Alaska is protected to the 100 µV m groundwave contour from co channel stations During nighttime hours a Class A station in Alaska is protected to the 100 µV m 50 percent skywave contour from co channel stations The 0 5 mV m groundwave contour is protected both daytime and nighttime from stations on adjacent channels Note In the Report and Order in MM Docket No 83 807 the Commission designated 15 stations operating on U S clear channels as Alaskan Class A stations Eleven of these stations already have Alaskan Class A facilities and are to be protected accordingly Permanent designation of the other four stations as Alaskan Class A is conditioned on their constructing minimum Alaskan Class A facilities no later than December 31 1989 Until that date or until such facilities are obtained these four stations shall be temporarily designated as Alaskan Class A stations and calculations involving these stations should be based on existing facilities but with an assumed power of 10 kW Thereafter these stations are to be protected based on their actual Alaskan Class A facilities If any of these stations does not obtain Alaskan Class A facilities in the period specified it is to be protected as a Class B station based on its actual facilities These four stations may increase power to 10 kW without regard to the impact on co channel Class B stations However power increases by these stations above 10 kW or by existing Alaskan Class A stations beyond their current power level are subject to applicable protection requirements for co channel Class B stations Other stations not on the original list but which meet applicable requirements may obtain Alaskan Class A status by seeking such designation from the Commission If a power increase | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
or other change in facilities by a station not on the original list is required to obtain minimum Alaskan Class A facilities any such application shall meet the interference protection requirements applicable to an Alaskan Class A proposal on the channel 47 CFR 73 182 a 1 ii enhanced display page 65 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 182 a 2 Radio Broadcast Services 2 Class B stations are stations which operate on clear and regional channels with powers not less than 0 25 kW nor more than 50 kW These stations render primary service only the area of which depends on their geographical location power and frequency It is recommended that Class B stations be located so that the interference received from other stations will not limit the service area to a groundwave contour value greater than 2 0 mV m nighttime and to the 0 5 mV m groundwave contour daytime which are the values for the mutual protection between this class of stations and other stations of the same class Note See 73 21 b 1 and 73 26 b concerning power restrictions and classifications relative to Class B Class C and Class D stations in Alaska Hawaii Puerto Rico and the U S Virgin Islands Stations in the above named places that are reclassified from Class C to Class B stations under 73 26 b shall not be authorized to increase power to levels that would increase the nighttime interference free limit of co channel Class C stations in the conterminous United States 3 Class C stations operate on local channels normally rendering primary service to a community and the suburban or rural areas immediately contiguous thereto with powers not less than 0 25 kW | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
nor more than 1 kW except as provided in 73 21 c 1 Such stations are normally protected to the daytime 0 5 mV m contour On local channels the separation required for the daytime protection shall also determine the nighttime separation Where directional antennas are employed daytime by Class C stations operating with more than 0 25 kW power the separations required shall in no case be less than those necessary to afford protection assuming nondirectional operation with 0 25 kW In no case will 0 25 kW or greater nighttime power be authorized to a station unable to operate nondirectionally with a power of 0 25 kW during daytime hours The actual nighttime limitation will be calculated For nighttime protection purposes Class C stations in the 48 contiguous United States may assume that stations in Alaska Hawaii Puerto Rico and the U S Virgin Islands operating on 1230 1240 1340 1400 1450 and 1490 kHz are Class C stations 4 Class D stations operate on clear and regional channels with daytime powers of not less than 0 25 kW or equivalent RMS field of 107 5 mV m at 1 kilometer if less than 0 25 kW and not more than 50 kW Class D stations that have previously received nighttime authority to operate with powers of less 0 25 kW or equivalent RMS fields of less than 107 5 mV m at 1 kilometer are not required to provide nighttime coverage in accordance with 73 24 i and are not protected from interference during nighttime hours Such nighttime authority is permitted on the basis of full nighttime protection being afforded to all Class A and Class B stations b When a station is already limited by interference from other stations to a contour value greater than that | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
normally protected for its class the individual received limits shall be the established standard for such station with respect to interference from each other station c The four classes of AM broadcast stations have in general three types of service areas i e primary secondary and intermittent See 73 14 for the definitions of primary secondary and intermittent service areas Class A stations render service to all three areas Class B stations render service to a primary area but the secondary and intermittent service areas may be materially limited or destroyed due to interference from other stations depending on the station assignments involved Class C and Class D 47 CFR 73 182 c enhanced display page 66 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 182 d Radio Broadcast Services stations usually have only primary service areas Interference from other stations may limit intermittent service areas and generally prevents any secondary service to those stations which operate at night Complete intermittent service may still be obtained in many cases depending on the station assignments involved d The groundwave signal strength required to render primary service is 2 mV m for communities with populations of 2 500 or more and 0 5 mV m for communities with populations of less than 2 500 See 73 184 for curves showing distance to various groundwave field strength contours for different frequencies and ground conductivities and also see 73 183 Groundwave signals e A Class C station may be authorized to operate with a directional antenna during daytime hours providing the power is at least 0 25 kW In computing the degrees of protection which such antenna will afford the radiation produced by the directional antenna system will be assumed to be no less in | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
any direction than that which would result from non directional operation using a single element of the directional array with 0 25 kW f All classes of broadcast stations have primary service areas subject to limitation by fading and noise and interference from other stations to the contours set out for each class of station g Secondary service is provided during nighttime hours in areas where the skywave field strength 50 or more of the time is 0 5 mV m or greater 0 1 mV m in Alaska Satisfactory secondary service to cities is not considered possible unless the field strength of the skywave signal approaches or exceeds the value of the groundwave field strength that is required for primary service Secondary service is subject to some interference and extensive fading whereas the primary service area of a station is subject to no objectionable interference or fading Only Class A stations are assigned on the basis of rendering secondary service Note Standards have not been established for objectionable fading because of the relationship to receiver characteristics Selective fading causes audio distortion and signal strength reduction below the noise level objectionable characteristics inherent in many modern receivers The AVC circuits in the better designed receivers generally maintain the audio output at a sufficiently constant level to permit satisfactory reception during most fading conditions h Intermittent service is rendered by the groundwave and begins at the outer boundary of the primary service area and extends to a distance where the signal strength decreases to a value that is too low to provide any service This may be as low as a few µV m in certain areas and as high as several millivolts per meter in other areas of high noise level interference from other stations or objectionable fading at night | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
The intermittent service area may vary widely from day to night and generally varies over shorter intervals of time Only Class A stations are protected from interference from other stations to the intermittent service area i Broadcast stations are licensed to operate unlimited time limited time daytime share time and specified hours See 73 1710 73 1725 73 1720 73 1715 and 73 1730 Applications for new stations shall specify unlimited time operation only 47 CFR 73 182 i enhanced display page 67 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 182 j Radio Broadcast Services j Section 73 24 sets out the general requirements for modifying the facilities of a licensed station and for establishing a new station Sections 73 24 b and 73 37 include interference related provisions that be considered in connection with an application to modify the facilities of an existing station or to establish a new station Section 73 30 describes the procedural steps required to receive an authorization to operate in the 1605 1705 kHz band k Objectionable nighttime interference from a broadcast station occurs when at a specified field strength contour with respect to the desired station the field strength of an undesired station co channel or first adjacent channel after application of proper protection ratio exceeds for 10 or more of the time the values set forth in these standards The value derived from the root sum square of all interference contributions represents the extent of a station s interference free coverage 1 With respect to the root sum square RSS values of interfering field strengths referred to in this section calculation of nighttime interference free service is accomplished by considering the signals on the three channels of concern co and first adjacencies | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
in order of decreasing magnitude adding the squares of the values and extracting the square root of the sum excluding those signals which are less than 50 of the RSS values of the higher signals already included 2 With respect to the root sum square values of interfering field strengths referred to in this section calculation of nighttime interference for non coverage purposes is accomplished by considering the signals on the three channels of concern co and first adjacencies in order of decreasing magnitude adding the squares of the values and extracting the square root of the sum excluding those signals which are less than 25 of the RSS values of the higher signals already included 3 With respect to the root sum square values of interfering field strengths referred to in this section calculation is accomplished by considering the signals on the three channels of concern co and first adjacencies in order of decreasing magnitude adding the squares of the values and extracting the square root of the sum The 0 exclusion method applies only to the determination of an improvement factor value for evaluating a station s eligibility for migration to the band 1605 1705 kHz 4 The RSS value will not be considered to be increased when a new interfering signal is added which is less than the appropriate exclusion percentage as applied to the RSS value of the interference from existing stations and which at the same time is not greater than the smallest signal included in the RSS value of interference from existing stations 5 It is recognized that application of the above 50 exclusion method or any exclusion method using a per cent value greater than zero of calculating the RSS interference may result in some cases in anomalies wherein the addition of a | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
new interfering signal or the increase in value of an existing interfering signal will cause the exclusion of a previously included signal and may cause a decrease in the calculated RSS value of interference In order to provide the Commission with more realistic information regarding gains and losses in service as a basis for determination of the relative merits of a proposed operation the following alternate method for calculating the proposed RSS values of interference will be employed wherever applicable 6 In the cases where it is proposed to add a new interfering signal which is not less than 50 or 25 depending on which study is being performed of the RSS value of interference from existing stations or which is greater that the smallest signal already included to obtain this RSS value the RSS limitation after addition of the new signal shall be calculated without excluding any signal 47 CFR 73 182 k 6 enhanced display page 68 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 182 k 7 Radio Broadcast Services previously included Similarly in cases where it is proposed to increase the value of one of the existing interfering signals which has been included in the RSS value the RSS limitation after the increase shall be calculated without excluding the interference from any source previously included 7 If the new or increased signal proposed in such cases is ultimately authorized the RSS values of interference to other stations affected will thereafter be calculated by the 50 exclusion or 25 exclusion depending on which study is being performed method without regard to this alternate method of calculation 8 Examples of RSS interference calculations i Existing interferences Station No 1 1 00 mV m Station No 2 0 60 mV | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
m Station No 3 0 59 mV m Station No 4 0 58 mV m The RSS value from Nos 1 2 and 3 is 1 31 mV m therefore interference from No 4 is excluded for it is less than 50 of 1 31 mV m ii Station A receives interferences from Station No 1 1 00 mV m Station No 2 0 60 mV m Station No 3 0 59 mV m It is proposed to add a new limitation 0 68 mV m This is more than 50 of 1 31 mV m the RSS value from Nos 1 2 and 3 The RSS value of Station No 1 and of the proposed station would be 1 21 m Vm which is more than twice as large as the limitation from Station No 2 or No 3 However under the above provision the new signal and the three existing interferences are nevertheless calculated for purposes of comparative studies resulting in an RSS value of 1 47 mV m However if the proposed station is ultimately authorized only No 1 and the new signal are included in all subsequent calculations for the reason that Nos 2 and 3 are less than 50 of 1 21 mV m the RSS value of the new signal and No 1 iii Station A receives interferences from Station No 1 1 00 mV m Station No 2 0 60 mV m Station No 3 0 59 mV m 47 CFR 73 182 k 8 iii enhanced display page 69 of 580 47 CFR Part 73 up to date as of 2 20 2024 47 CFR 73 182 l Radio Broadcast Services No 1 proposes to increase the limitation it imposes on Station A to 1 21 mV m Although the limitations from | corpus_data/corpus_txt/47-CFR-Part-73-_up-to-date-as-of-2-20-2024_.txt |
Subsets and Splits