AM, FM, and Television Broadcast Single Frequency/Channel Maps

About Single Frequency Maps for AM, FM, and TV

The AM Maps by Frequency, FM Maps by Frequency, and TV Maps by Channel tabs on the left open searches of AM and FM frequencies, or Television channels.  Click on a frequency or channel to generate a map of the AM, FM, or TV licensed stations in the USA that are using the specific frequency or channel.  AM options include daytime groundwave coverage and nighttime primary and secondary skywave coverage. FM results  include licensed FM stations, low power FM (LPFM) stations, and FM translator (repeater) stations.  TV results include full service television as well as Class A TV and low power stations.  These maps -- which show the nationwide distribution of stations on a specific frequency -- are useful for eyeballing broadcast radio or television service to a desired region.  They are also helpful for DXing (long distance listening), particularly on the AM broadcast band at night. Google Earth (or other KML browser) must be installed on your device.  We strongly recommend that you review the Making These Maps Work for You and Map Considerations tabs on the left, to learn how to make the maps function on your device. Please be aware that these maps are subject to change and correction without notice, and the contours shown may not always correspond to service contours and areas used in broadcast radio application processing.  Use the maps at your own risk, the FCC makes no representation of their suitability for any particular purpose.

Comments may be directed to Dale.Bickel, dale.bickel@fcc.gov.

 

Low power Travelers' Information Stations in the AM band are not shown.  In the USA, 530 kHz and 1610 kHz are used for TIS stations, but they may be used on any AM frequency on a non-interference basis. (Also called "Highway Advisory Radio".)

Nighttime skywave service is dependent on several factors, including seasonal effects, atmospheric fading, and the sunspot cycle.  Secondary nighttime skywave service (orange contour) is also dependent on whether interference exists from other stations.  We make no determination here as to signal quality at any given location.

Nighttime skywave contours for stations outside the USA are based on notified parameters, some of which might be years out of date.  They are included to show potential limitations on U.S. AM broadcast station service, and to help identify such signals.  We do not guarantee accuracy for such records.  There are no plans to add daytime groundwave contours for stations outside the USA.

AM Records are divided into two sections - East (of 90° W Longitude) and West (of 90°W Longitude. . This division ensures that all records in that region are loaded into Google Earth for display.  For best results, allow one region's records to fully display before adding additional contour maps.

Contours are provided as-is, and users should be aware that the mapped information may not be identical to that used for radio broadcast application processing.

 

FM Single Frequency Maps

• Protected Service Contours for FM and Low Power FM (LPFM) stations (light blue)
• 60 dBu secondary service contours for FM translators (pink)
• Stations outside the USA ae not included.

 

Service:      ALL - FM, LPFM, and FM TranslatorsFM - FM full service stations onlyLPFM - Low Power FM stations onlyFM Translator stations only

Frequency: 

Map area:   EAST of 85° West Longitude (Eastern USA)WEST of 85° to 105° West Longitude (Central USA)WEST of 105° West Longitude (Western USA)

     

 

FM Records are divided into three sections - East (of 85° W Longitude), Central (between 85°, and 105° West Longitude) and West (of 105° W Longitude. . These divisions ensure that all records in that region are loaded into Google Earth for display.  For best results, allow one region's records to fully display before adding additional contour maps.

Contours are provided as-is, and users should be aware that the mapped information may not be identical to that used for radio broadcast application processing.

 

TV Single Channel Maps

• Protected Service Contours for Full Service Television (light blue)
• Class A Television service contours
• Low Power Television and TV Translator service contours

 

Service:      ALL - Full Service + Class A + Low Power TVFull service TV (DTV + DTS) - light blueClass A Television (DCA)Low Power Television (Digital and Analog)

Transmit Channel:  (may differ from the channel the viewer sees)

Map area:   EAST of 85° West Longitude (Eastern USA)WEST of 85° to 105° West Longitude (Central USA)WEST of 105° West Longitude (Western USA)

     

 

TV Records are divided into three sections - East (of 85° W Longitude), Central (between 85°, and 105° West Longitude) and West (of 105° W Longitude. . These divisions ensure that all records in that region are loaded into Google Earth for display.  For best results, allow one region's records to fully display before adding additional contour maps.

Contours are provided as-is, and users should be aware that the mapped information may not be identical to that used for television broadcast application processing.

 

Map Considerations

FM Stations:  FM and Low Power FM (service codes FM and FL) service contours are plotted using light blue lines at the field strength applicable to the station class and location (see FM Station Classes and Service Contours for details).  FM translators' service contours are plotted in pink at the location corresponding to a 60 dBu field strength.

AM Daytime Groundwave Service Contour:  Daytime coverage is generally protected from interference caused by other stations within the 0.5 mV/m (millivolts per meter electric field strength) contour.  This will be shown by the light blue lines on the map.  During the daytime there is little to no skywave propagation, so skywave interference does not normally occur.  The 2.0 mV/m contour is also shown (green); for Class B stations this defines the nighttime protected service area.

AM Nighttime Skywave Service:  Coverage resulting from skywave propagation of AM nighttime signals is rather complex and we only touch on it briefly here.  In many cases, skywave coverage must be evaluated along with nighttime groundwave signals.  These maps do not consider all factors, thus, actual nighttime service may differ from that portrayed on these maps.  However, the maps do provide a useful approximation of what service may be anticipated.

• For Class A AM stations, protected skywave coverage extends out to the 0.5 mV/m skywave contour, or 750 miles maximum, whichever is smaller.  These maps just show the nighttime skywave contour in blue for Class A stations.  Secondary service extends beyond the 0.5 mV.m contour.
• For Class B AM stations, protected service extends out to the 2.0 mV/m daytime groundwave service contour (green), or the 2.0 mV/m nighttime groundwave service contour (not presently available).  Service beyond that 2.0 mV/m contour, out to the 0.5 mv/m conrour, is considered a secondary service that is not protected from interference from other stations. 
• For Class C AM stations, protected service at night is the 0.5 mV/m daytime groundwave service contour, and secondary service (which is not protected from interference) can occur out to the 0.5 mV.m nighttime contour (orange).
• Class D AM stations receive no protection for any nighttime service.  Most Class D stations that are permitted to operate at night do so at very low power levels and provide very local service.
• Some AM stations do not operate with enough nighttime power to generate any 0.5 mV/m  nighttime service contour.  In such cases, only the transmitter site is shown on the nighttime map.

Again, there is no way that this brief summary can account for every station's nighttime interference-free coverage.