1) US Mediumwave Data 540-1700 KHz
Files are in HTML format and contain every licensed US station in the FCC database. They can be viewed in any browser. In the .zip you will also find a comma-separated-values (.CSV) file of all stations which can be viewed in spreadsheet format by programs like Excel. A table file showing all stations in grid format is also included. The HTML files contain clickable links which will take you to various informational pages for each station within the FCC web site.
2) US Pattern Reference 540-1700 KHz
Included is a complete set of GoogleMap-based, HTML-driven maps which show the most current pattern plots of all licensed US mediumwave broadcast stations. The updated set now shows patterns calculated at the 0.15 millivolt per meter (fringe) contour level based on actual US ground conductivities. It includes all frequencies for the indicated services: Unlimited, Daytime, Nighttime, and Critical Hours. Individual maps are grouped by channel frequency: 540, 550, 560 KHz, etc.
Note that these maps show expected groundwave coverage patterns for each service, not skywave. Skywave maps can be produced by Radio Data MW, but are better printed out on a station-by-station basis. Use of the program is required.
HOW THEY ARE PRODUCED
Using the actual FCC database files Radio Data MW will auto-generate an interactive HTML pattern map, showing the pattern plots for all stations included at the discretion of the user. A complete set of mediumwave pattern maps can be generated. Radio Data MW generates a real pattern plot based on ground conductivity, ground dielectric constant, and can display actual (but approximate of course) signal level boundaries for Local, Distant, Fringe, Extreme mV/m levels, or any custom mV/m level chosen by the user.
The online Google Maps API is used to generate and plot each station on a map of the US. An accurate flag pin is placed at each transmitter location, and in satellite view may be zoomed in to see the actual transmitter site. Map flags are color-coded to indicate Unlimited (light red), Daytime (yellow), Nighttime (black), and Critical Hours (grey) services. Each flag has a tooltip-type note, and when hovered over with the mouse will display a note on the station.
A pattern plot for each station is generated and displayed. Each pattern is calculated using standard formulas used by the FCC to compute the base values at one kilometer, and field strength formulas at distance based on the works of many people over the years. See Field Strength Calculations: A History and Field Strength Calculator One, previously posted on RADIO-TIMETRAVELLER.
Finally, an accurate ray path can be drawn from all transmitters to a user-specified receiving location by inputting latitude-longitude coordinates. Super-imposed on the pattern plots, the ray paths show the listener where he or she falls on each station's pattern, a handy guide to knowing where you stand.
USING THE MAPS
Note again that these maps are web-based. As stated, they use Google Maps and thus require access to Google. In order to view them you need a connection to the internet.
Desktop browsers: Not a problem, all seem to work well. Maps have been tested in the Internet Explorer, Firefox, Chrome, Opera and Safari browsers. If using Internet Explorer, best results are had with version 10 or greater.
Phone or tablet browsers: Maps may work on tablet or phone browsers, but no guarantee is given.
These are the latest US pattern references available, and coverage is based on actual ground conductivities.
Hope you enjoy these files.
Click image to enlarge.
|640 KHz, 0.15 mV/m fringe distance|