Table of Parts
Subpart A—AM Broadcast Stations
Sec. 73.1 Scope.
Sec. 73.14 AM broadcast definitions.
Sec. 73.21 Classes of AM broadcast channels and stations.
Sec. 73.23 AM broadcast station applications affected by international
Sec. 73.24 Broadcast facilities; showing required.
Sec. 73.25 Clear channels; Class A, Class B and Class D stations.
Sec. 73.26 Regional channels; Class B and Class D stations.
Sec. 73.27 Local channels; Class C stations.
Sec. 73.28 Assignment of stations to channels.
Sec. 73.29 Class C stations on regional channels.
Sec. 73.30 Petition for authorization of an allotment in the 1605–1705 kHz
Sec. 73.31 Rounding of nominal power specified on applications.
Sec. 73.33 Antenna systems; showing required.
Sec. 73.35 Calculation of improvement factors.
Sec. 73.37 Applications for broadcast facilities, showing required.
Sec. 73.44 AM transmission system emission limitations.
Sec. 73.45 AM antenna systems.
Sec. 73.49 AM transmission system fencing requirements.
Sec. 73.51 Determining operating power.
Sec. 73.53 Requirements for authorization of antenna monitors.
Sec. 73.54 Antenna resistance and reactance measurements.
Sec. 73.57 Remote reading antenna and common point ammeters.
Sec. 73.58 Indicating instruments.
Sec. 73.61 AM directional antenna field strength measurements.
Sec. 73.62 Directional antenna system tolerances.
Sec. 73.68 Sampling systems for antenna monitors.
Sec. 73.69 Antenna monitors.
Sec. 73.72 Operating during the experimental period.
Sec. 73.88 Blanketing interference.
Sec. 73.99 Presunrise service authorization (PSRA) and postsunset service
Sec. 73.127 Use of multiplex transmission.
Sec. 73.128 AM stereophonic broadcasting.
Sec. 73.132 Territorial exclusivity.
Sec. 73.150 Directional antenna systems.
Sec. 73.151 Field strength measurements to establish performance of
Sec. 73.152 Modification of directional antenna data.
Sec. 73.153 Field strength measurements in support of applications or
evidence at hearings.
Sec. 73.154 AM directional antenna partial proof of performance measurements.
Sec. 73.157 Antenna testing during daytime.
Sec. 73.158 Directional antenna monitoring points.
Sec. 73.160 Vertical plane radiation characteristics, f(&b.thetas;).
Sec. 73.182 Engineering standards of allocation.
Sec. 73.183 Groundwave signals.
Sec. 73.184 Groundwave field strength graphs.
Sec. 73.185 Computation of interfering signal.
Sec. 73.186 Establishment of effective field at one kilometer.
Sec. 73.187 Limitation on daytime radiation.
Sec. 73.189 Minimum antenna heights or field strength requirements.
Sec. 73.190 Engineering charts and related formulas.
Subpart B—FM Broadcast Stations
Sec. 73.201 Numerical designation of FM broadcast channels.
Sec. 73.202 Table of Allotments.
Sec. 73.203 Availability of channels.
Sec. 73.204 International agreements and other restrictions on use of
Sec. 73.205 Zones.
Sec. 73.207 Minimum distance separation between stations.
Sec. 73.208 Reference points and distance computations.
Sec. 73.209 Protection from interference.
Sec. 73.210 Station classes.
Sec. 73.211 Power and antenna height requirements.
Sec. 73.212 Administrative changes in authorizations.
Sec. 73.213 Grandfathered short-spaced stations.
Sec. 73.215 Contour protection for short-spaced assignments.
Sec. 73.220 Restrictions on use of channels.
Sec. 73.232 Territorial exclusivity.
Sec. 73.239 Use of common antenna site.
Sec. 73.258 Indicating instruments.
Sec. 73.267 Determining operating power.
Sec. 73.277 Permissible transmissions.
Sec. 73.293 Use of FM multiplex subcarriers.
Sec. 73.295 FM subsidiary communications services.
Sec. 73.297 FM stereophonic sound broadcasting.
Sec. 73.310 FM technical definitions.
Sec. 73.311 Field strength contours.
Sec. 73.312 Topographic data.
Sec. 73.313 Prediction of coverage.
Sec. 73.314 Field strength measurements.
Sec. 73.315 FM transmitter location.
Sec. 73.316 FM antenna systems.
Sec. 73.317 FM transmission system requirements.
Sec. 73.318 FM blanketing interference.
Sec. 73.319 FM multiplex subcarrier technical standards.
Sec. 73.322 FM stereophonic sound transmission standards.
Sec. 73.333 Engineering charts.
Subpart C—Noncommercial Educational FM Broadcast Stations
Sec. 73.501 Channels available for assignment.
Sec. 73.503 Licensing requirements and service.
Sec. 73.504 Channel assignments in the Mexican border area.
Sec. 73.505 Zones.
Sec. 73.506 Classes of noncommercial educational FM stations and channels.
Sec. 73.507 Minimum distance separations between stations.
Sec. 73.508 Standards of good engineering practice.
Sec. 73.509 Prohibited overlap.
Sec. 73.510 Antenna systems.
Sec. 73.511 Power and antenna height requirements.
Sec. 73.512 Special procedures applicable to Class D noncommercial
Sec. 73.513 Noncommercial educational FM stations operating on unreserved
Sec. 73.514 Protection from interference.
Sec. 73.515 NCE FM transmitter location.
Sec. 73.525 TV Channel 6 protection.
Sec. 73.558 Indicating instruments.
Sec. 73.561 Operating schedule; time sharing.
Sec. 73.567 Determining operating power.
Sec. 73.593 Subsidiary communications services.
Sec. 73.597 FM stereophonic sound broadcasting.
Sec. 73.599 NCE-FM engineering charts.
Subpart D [Reserved]
Subpart E—Television Broadcast Stations
Sec. 73.601 Scope of subpart.
Sec. 73.602 Cross reference to rules in other parts.
Sec. 73.603 Numerical designation of television channels.
Sec. 73.606 Table of allotments.
Sec. 73.607 Availability of channels.
Sec. 73.609 Zones.
Sec. 73.610 Minimum distance separations between stations.
Sec. 73.611 Reference points and distance computations.
Sec. 73.612 Protection from interference.
Sec. 73.613 Protection of Class A TV stations.
Sec. 73.614 Power and antenna height requirements.
Sec. 73.615 Administrative changes in authorizations.
Sec. 73.621 Noncommercial educational TV stations.
Sec. 73.622 Digital television table of allotments.
Sec. 73.623 DTV applications and changes to DTV allotments.
Sec. 73.624 Digital television broadcast stations.
Sec. 73.625 DTV coverage of principal community and antenna system.
Sec. 73.635 Use of common antenna site.
Sec. 73.641 Subscription TV definitions.
Sec. 73.642 Subscription TV service.
Sec. 73.643 Subscription TV operating requirements.
Sec. 73.644 Subscription TV transmission systems.
Sec. 73.646 Telecommunications Service on the Vertical Blanking Interval and
in the Visual Signal.
Sec. 73.653 Operation of TV aural and visual transmitters.
Sec. 73.658 Affiliation agreements and network program practices; territorial
exclusivity in non-network program arrangements.
Sec. Sec. 73.659-73.663 [Reserved]
Sec. 73.664 Determining operating power.
Sec. 73.665 Use of TV aural baseband subcarriers.
Sec. 73.667 TV subsidiary communications services.
Sec. 73.669 TV stereophonic aural and multiplex subcarrier operation.
Sec. 73.670 Commercial limits in children's programs.
Sec. 73.671 Educational and informational programming for children.
Sec. 73.672 [Reserved]
Sec. 73.673 Public information initiatives regarding educational and
informational programming for children.
Sec. 73.681 Definitions.
Sec. 73.682 TV transmission standards.
Sec. 73.683 Field strength contours and presumptive determination of field
strength at individual locations.
Sec. 73.684 Prediction of coverage.
Sec. 73.685 Transmitter location and antenna system.
Sec. 73.686 Field strength measurements.
Sec. 73.687 Transmission system requirements.
Sec. 73.688 Indicating instruments.
Sec. 73.691 Visual modulation monitoring.
Sec. 73.698 Tables.
Sec. 73.699 TV engineering charts.
Subpart F—International Broadcast Stations
Sec. 73.701 Definitions.
Sec. 73.702 Assignment and use of frequencies.
Sec. 73.703 Geographical zones and areas of reception.
Sec. 73.712 Equipment tests.
Sec. 73.713 Program tests.
Sec. 73.731 Licensing requirements.
Sec. 73.732 Authorizations.
Sec. 73.733 Normal license period.
Sec. 73.751 Operating power.
Sec. 73.753 Antenna systems.
Sec. 73.754 Frequency monitors.
Sec. 73.755 Modulation monitors.
Sec. 73.756 System specifications for double-sideband (DBS) modulated
emissions in the HF broadcasting service.
Sec. 73.757 System specifications for single-sideband (SSB) modulated
emissions in the HF broadcasting service.
Sec. 73.758 System specifications for digitally modulated emissions in the HF
Sec. 73.759 Auxiliary transmitters.
Sec. 73.760 Alternate main transmitters.
Sec. 73.761 Modification of transmission systems.
Sec. 73.762 Time of operation.
Sec. 73.765 Determining operating power.
Sec. 73.766 [Reserved]
Sec. 73.781 Logs.
Sec. 73.782 Retention of logs.
Sec. 73.787 Station identification.
Sec. 73.788 Service; commercial or sponsored programs.
Subpart G—Low Power FM Broadcast Stations (LPFM)
Sec. 73.801 Broadcast regulations applicable to LPFM stations.
Sec. 73.805 Availability of channels.
Sec. 73.807 Minimum distance separation between stations.
Sec. 73.808 Distance computations.
Sec. 73.809 Interference protection to full service FM stations.
Sec. 73.810 Third adjacent channel complaint and license modification
Sec. 73.811 LPFM power and antenna height requirements.
Sec. 73.812 Rounding of power and antenna heights.
Sec. 73.813 Determination of antenna height above average terrain (HAAT).
Sec. 73.816 Antennas.
Sec. 73.825 Protection to reception of TV channel 6.
Sec. 73.827 Interference to the input signals of FM translator or FM booster
Sec. 73.840 Operating power and mode tolerances.
Sec. 73.845 Transmission system operation.
Sec. 73.850 Operating schedule.
Sec. 73.853 Licensing requirements and service.
Sec. 73.854 Unlicensed operations.
Sec. 73.855 Ownership limits.
Sec. 73.858 Attribution of LPFM station interests.
Sec. 73.860 Cross-ownership.
Sec. 73.865 Assignment and transfer of LPFM authorizations.
Sec. 73.870 Processing of LPFM broadcast station applications.
Sec. 73.871 Amendment of LPFM broadcast station applications.
Sec. 73.872 Selection procedure for mutually exclusive LPFM applications.
Sec. 73.873 LPFM license period.
Sec. 73.875 Modification of transmission systems.
Sec. 73.877 Station logs for LPFM stations.
Sec. 73.878 Station inspections by FCC; availability to FCC of station logs
Sec. 73.879 Signal retransmission.
Sec. 73.881 Equal employment opportunities.
Subpart H—Rules Applicable to All Broadcast Stations
Sec. 73.1001 Scope.
Sec. 73.1010 Cross reference to rules in other parts.
Sec. 73.1015 Truthful written statements and responses to Commission
inquiries and correspondence.
Sec. 73.1020 Station license period.
Sec. 73.1030 Notifications concerning interference to radio astronomy,
research and receiving installations.
Sec. 73.1120 Station location.
Sec. 73.1125 Station main studio location.
Sec. 73.1150 Transferring a station.
Sec. 73.1201 Station identification.
Sec. 73.1202 Retention of letters received from the public.
Sec. 73.1206 Broadcast of telephone conversations.
Sec. 73.1207 Rebroadcasts.
Sec. 73.1208 Broadcast of taped, filmed, or recorded material.
Sec. 73.1209 References to time.
Sec. 73.1210 TV/FM dual-language broadcasting in Puerto Rico.
Sec. 73.1211 Broadcast of lottery information.
Sec. 73.1212 Sponsorship identification; list retention; related
Sec. 73.1213 Antenna structure, marking and lighting.
Sec. 73.1215 Specifications for indicating instruments.
Sec. 73.1216 Licensee-conducted contests.
Sec. 73.1217 Broadcast hoaxes.
Sec. 73.1225 Station inspections by FCC.
Sec. 73.1226 Availability to FCC of station logs and records.
Sec. 73.1230 Posting of station license.
Sec. 73.1250 Broadcasting emergency information.
Sec. 73.1300 Unattended station operation.
Sec. 73.1350 Transmission system operation.
Sec. 73.1400 Transmission system monitoring and control.
Sec. 73.1510 Experimental authorizations.
Sec. 73.1515 Special field test authorizations.
Sec. 73.1520 Operation for tests and maintenance.
Sec. 73.1530 Portable test stations [Definition].
Sec. 73.1540 Carrier frequency measurements.
Sec. 73.1545 Carrier frequency departure tolerances.
Sec. 73.1560 Operating power and mode tolerances.
Sec. 73.1570 Modulation levels: AM, FM, TV and Class A TV aural.
Sec. 73.1580 Transmission system inspections.
Sec. 73.1590 Equipment performance measurements.
Sec. 73.1610 Equipment tests.
Sec. 73.1615 Operation during modification of facilities.
Sec. 73.1620 Program tests.
Sec. 73.1635 Special temporary authorizations (STA).
Sec. 73.1650 International agreements.
Sec. 73.1660 Acceptability of broadcast transmitters.
Sec. 73.1665 Main transmitters.
Sec. 73.1670 Auxiliary transmitters.
Sec. 73.1675 Auxiliary antennas.
Sec. 73.1680 Emergency antennas.
Sec. 73.1690 Modification of transmission systems.
Sec. 73.1692 Broadcast station construction near or installation on an AM
Sec. 73.1695 Changes in transmission standards.
Sec. 73.1700 Broadcast day.
Sec. 73.1705 Time of operation.
Sec. 73.1710 Unlimited time.
Sec. 73.1715 Share time.
Sec. 73.1720 Daytime.
Sec. 73.1725 Limited time.
Sec. 73.1730 Specified hours.
Sec. 73.1735 AM station operation pre-sunrise and post-sunset.
Sec. 73.1740 Minimum operating schedule.
Sec. 73.1745 Unauthorized operation.
Sec. 73.1750 Discontinuance of operation.
Sec. 73.1800 General requirements related to the station log.
Sec. 73.1820 Station log.
Sec. 73.1835 Special technical records.
Sec. 73.1840 Retention of logs.
Sec. 73.1870 Chief operators.
Sec. 73.1910 Fairness Doctrine.
Sec. 73.1940 Legally qualified candidates for public office.
Sec. 73.1941 Equal opportunities.
Sec. 73.1942 Candidate rates.
Sec. 73.1943 Political file.
Sec. 73.1944 Reasonable access.
Sec. 73.2080 Equal employment opportunities (EEO).
Sec. 73.3500 Application and report forms.
Sec. 73.3511 Applications required.
Sec. 73.3512 Where to file; number of copies.
Sec. 73.3513 Signing of applications.
Sec. 73.3514 Content of applications.
Sec. 73.3516 Specification of facilities.
Sec. 73.3517 Contingent applications.
Sec. 73.3518 Inconsistent or conflicting applications.
Sec. 73.3519 Repetitious applications.
Sec. 73.3520 Multiple applications.
Sec. 73.3521 Mutually exclusive applications for low power television,
television translators and television booster stations.
Sec. 73.3522 Amendment of applications.
Sec. 73.3523 Dismissal of applications in renewal proceedings.
Sec. 73.3525 Agreements for removing application conflicts.
Sec. 73.3526 Local public inspection file of commercial stations.
Sec. 73.3527 Local public inspection file of noncommercial educational
Sec. 73.3533 Application for construction permit or modification of
Sec. 73.3534 [Reserved]
Sec. 73.3536 Application for license to cover construction permit.
Sec. 73.3537 Application for license to use former main antenna as an
Sec. 73.3538 Application to make changes in an existing station.
Sec. 73.3539 Application for renewal of license.
Sec. 73.3540 Application for voluntary assignment or transfer of control.
Sec. 73.3541 Application for involuntary assignment of license or transfer of
Sec. 73.3542 Application for emergency authorization.
Sec. 73.3543 Application for renewal or modification of special service
Sec. 73.3544 Application to obtain a modified station license.
Sec. 73.3545 Application for permit to deliver programs to foreign stations.
Sec. 73.3549 Requests for extension of time to operate without required
monitors, indicating instruments, and EAS encoders and decoders.
Sec. 73.3550 Requests for new or modified call sign assignments.
Sec. 73.3555 Multiple ownership.
Sec. 73.3556 Duplication of programming on commonly owned or time brokered
Sec. 73.3561 Staff consideration of applications requiring Commission action.
Sec. 73.3562 Staff consideration of applications not requiring action by the
Sec. 73.3564 Acceptance of applications.
Sec. 73.3566 Defective applications.
Sec. 73.3568 Dismissal of applications.
Sec. 73.3571 Processing of AM broadcast station applications.
Sec. 73.3572 Processing of TV broadcast, Class A TV broadcast, low power TV,
TV translators, and TV booster applications.
Sec. 73.3573 Processing FM broadcast station applications.
Sec. 73.3574 Processing of international broadcast station applications.
Sec. 73.3578 Amendments to applications for renewal, assignment or transfer
Sec. 73.3580 Local public notice of filing of broadcast applications.
Sec. 73.3584 Procedure for filing petitions to deny.
Sec. 73.3587 Procedure for filing informal objections.
Sec. 73.3588 Dismissal of petitions to deny or withdrawal of informal
Sec. 73.3589 Threats to file petitions to deny or informal objections.
Sec. 73.3591 Grants without hearing.
Sec. 73.3592 Conditional grant.
Sec. 73.3593 Designation for hearing.
Sec. 73.3594 Local public notice of designation for hearing.
Sec. 73.3597 Procedures on transfer and assignment applications.
Sec. 73.3598 Period of construction.
Sec. 73.3601 Simultaneous modification and renewal of license.
Sec. 73.3603 Special waiver procedure relative to applications.
Sec. 73.3605 Retention of applications in hearing status after designation
Sec. 73.3612 Annual employment report.
Sec. 73.3613 Filing of contracts.
Sec. 73.3615 Ownership reports.
Sec. 73.3617 Information available on the Internet.
Sec. 73.3999 Enforcement of 18 U.S.C. 1464 (restrictions on the transmission
of obscene and indecent material).
Sec. 73.4000 Listing of FCC policies.
Sec. 73.4005 Advertising—refusal to sell.
Sec. 73.4015 Applications for AM and FM construction permits, incomplete or
Sec. 73.4017 Application processing: Commercial FM stations.
Sec. 73.4045 Barter agreements.
Sec. 73.4050 Children's TV programs.
Sec. 73.4055 Cigarette advertising.
Sec. 73.4060 Citizens agreements.
Sec. 73.4075 Commercials, loud.
Sec. 73.4082 Comparative broadcast hearings—specialized programming formats.
Sec. 73.4091 Direct broadcast satellites.
Sec. 73.4094 Dolby encoder.
Sec. 73.4095 Drug lyrics.
Sec. 73.4097 EBS (now EAS) attention signals on automated programing systems.
Sec. 73.4099 Financial qualifications, certification of.
Sec. 73.4100 Financial qualifications; new AM and FM stations.
Sec. 73.4101 Financial qualifications, TV stations.
Sec. 73.4102 FAA communications, broadcast of.
Sec. 73.4104 FM assignment policies and procedures.
Sec. 73.4107 FM broadcast assignments, increasing availability of.
Sec. 73.4108 FM transmitter site map submissions.
Sec. 73.4110 Format changes of stations.
Sec. 73.4135 Interference to TV reception by FM stations.
Sec. 73.4140 Minority ownership; tax certificates and distress sales.
Sec. 73.4154 Network/AM, FM station affiliation agreements.
Sec. 73.4157 Network signals which adversely affect affiliate broadcast
Sec. 73.4163 Noncommercial nature of educational broadcast stations.
Sec. 73.4165 Obscene language.
Sec. 73.4170 Obscene broadcasts.
Sec. 73.4180 Payment disclosure: Payola, plugola, kickbacks.
Sec. 73.4185 Political broadcasting and telecasting, the law of.
Sec. 73.4190 Political candidate authorization notice and sponsorship
Sec. 73.4195 Political advertising by UHF translators.
Sec. 73.4210 Procedure Manual: “The Public and Broadcasting”.
Sec. 73.4215 Program matter: Supplier identification.
Sec. 73.4242 Sponsorship identification rules, applicability of.
Sec. 73.4246 Stereophonic pilot subcarrier use during monophonic programming.
Sec. 73.4247 STV: Competing applications.
Sec. 73.4250 Subliminal perception.
Sec. 73.4255 Tax certificates: Issuance of.
Sec. 73.4260 Teaser announcements.
Sec. 73.4265 Telephone conversation broadcasts (network and like sources).
Sec. 73.4266 Tender offer and proxy statements.
Sec. 73.4267 Time brokerage.
Sec. 73.4275 Tone clusters; audio attention-getting devices.
Sec. 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
Sec. 73.5000 Services subject to competitive bidding.
Sec. 73.5001 [Reserved]
Sec. 73.5002 Application and certification procedures; return of mutually
exclusive applications not subject to competitive bidding procedures;
prohibition of collusion.
Sec. 73.5003 Submission of full payments.
Sec. 73.5004 [Reserved]
Sec. 73.5005 Filing of long-form applications.
Sec. 73.5006 Filing of petitions to deny against long-form applications.
Sec. 73.5007 Designated entity provisions.
Sec. 73.5008 Definitions applicable for designated entity provisions.
Sec. 73.5009 Assignment or transfer of control.
Subpart J—Class A Television Broadcast Stations
Sec. 73.6000 Definitions.
Sec. 73.6001 Eligibility and service requirements.
Sec. 73.6002 Licensing requirements.
Sec. Sec. 73.6003-73.6005 [Reserved]
Sec. 73.6006 Channel assignments.
Sec. 73.6007 Power limitations.
Sec. 73.6008 Distance computations.
Sec. 73.6010 Class A TV station protected contour.
Sec. 73.6011 Protection of TV broadcast stations.
Sec. 73.6012 Protection of Class A TV, low power TV and TV translator
Sec. 73.6013 Protection of DTV stations.
Sec. 73.6014 Protection of digital Class A TV stations.
Sec. 73.6016 Digital Class A TV station protection of TV broadcast stations.
Sec. 73.6017 Digital Class A TV station protection of Class A TV and digital
Class A TV stations.
Sec. 73.6018 Digital Class A TV station protection of DTV stations.
Sec. 73.6019 Digital Class A TV station protection of low power TV, TV
translator, digital low power TV and digital TV translator stations.
Sec. 73.6020 Protection of stations in the land mobile radio service.
Sec. 73.6022 Negotiated interference and relocation agreements.
Sec. 73.6024 Transmission standards and system requirements.
Sec. 73.6025 Antenna system and station location.
Sec. 73.6026 Broadcast regulations applicable to Class A television stations.
Sec. 73.6027 Class A TV notifications concerning interference to radio
astronomy, research and receiving installations.
Subpart K—Application and Selection Procedures for Reserved Noncommercial
Educational Channels, and for Certain Applications for Noncommercial
Educational Stations on Non-Reserved Channels
Sec. 73.7000 Definition of terms (as used in subpart K only).
Sec. 73.7001 Services subject to evaluation by point system.
Sec. 73.7002 Fair distribution of service on reserved band FM channels.
Sec. 73.7003 Point system selection procedures.
Sec. 73.7004 Petitions to deny tentative selectee(s).
Sec. 73.7005 Holding period.
Subpart L—Digital Broadcast Television Redistribution Control
Sec. 73.8000 Incorporation by reference.
Subpart M—Digital Broadcast Television Redistribution Control
Sec. 73.9000 Definitions.
Sec. 73.9001 Redistribution control of digital television broadcasts.
Sec. 73.9002 Sale or distribution of demodulators, covered demodulator
products, and peripheral TSP products.
Sec. 73.9003 Compliance requirements for covered demodulator products:
Sec. 73.9004 Compliance requirements for covered demodulator products: Marked
Sec. 73.9005 Compliance requirements for covered demodulator products: Audio.
Sec. 73.9006 Add-in covered demodulator products.
Sec. 73.9007 Robustness requirements for covered demodulator products.
Sec. 73.9008 Interim approval of authorized digital output protection
technologies and authorized recording methods.
Sec. 73.9009 Manufacture for exportation.
Alphabetical Index—Part 73
Authority: 47 U.S.C. 154, 303, 334, 336.
Subpart A—AM Broadcast Stations