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Sunday, April 14, 2013

US Mediumwave Pattern Reference

Allow me to introduce another set of new files of interest to mediumwave DXers: US Mediumwave Pattern Reference, produced by Radio Data MW. You will find them at the top of the right sidebar under LATEST US MEDIUMWAVE FILES. Radio Data MW, a program I have been working on for the last three years, accomplishes this mapping process.

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 from 540 - 1700 KHz. The set 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.

DOWNLOAD

See the link at the top of the right sidebar under LATEST US MEDIUMWAVE FILES.

I will attempt to make this a regular feature on RADIO-TIMETRAVELLER, with regular yearly updates. The sidebar at the top right will have the most current links. The link will change for each new posting, so I would avoid copying and pasting it into a forum or other web page. Come to the main page of this blog instead.

INSTALLING

The maps are HTML-based, so no regular install is necessary. Simply unzip the downloaded file and click on the individual map file to run. The map will open up in your web browser. They are self-contained, with image icons embedded right into the code. You must have an internet connection to view the maps.

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 in a matter of minutes. 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, Daytime, Nighttime, and Critical Hours 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.

Note 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. In desktop or laptop use, they have been tested in the Internet Explorer, Firefox, Chrome, Opera, and Safari browsers. If using Internet Explorer, best results are had with the latest version. Chrome works best.

These maps will work on some tablet or phone browsers. I have tested them on an Android device and it's handy to be able to display them while DXing outside or on the road. Some browsers will not allow pinch-to-zoom, where others will. Some browsers don't render the map controls correctly. Response is fair to poor on the tablet or phone due to the sheer number of HTML lines and processing required to render the maps. Such is the current state of tablet and phone browser rendering.

Hope you enjoy these pattern maps and find them useful.

6 comments:

gkinsman said...

Bill,

Thanks for creating these U.S. MW pattern maps. I put the HTML files on my Windows 7 PC, and they display fine with Firefox.

I'll have to figure out the easiest way to use the maps on my Nexus 7 Android tablet. How did you set this up on your Android device?

Regards,
Gary

RADIO-TIMETRAVELLER said...

Gary,

Thanks. For transferring files from my laptop to my Android device I generally use an app called Airdroid which is on the Google Play Store. It's free. It transfers over WiFi, so you must have a Wifi router in your house.

Enable WiFi on the laptop and the Android device, start Airdroid, then log onto the Airdroid URL (http://192.168.x.x...) on the laptop. Files can be transferred using drag and drop. I use the "Download" folder to hold the files, which should be on every Android device.

Once the file or files are there, just click on one and it will open up in a browser. I use the Android Firefox browser on my smartphone.

Please check back in if you have any other questions. I'll be glad to help if I can.

Bill

Other WiFi transfer apps are available, but I've found this one the best.

Dr. Coyote said...

Thanks for the pattern maps. In addition to the list of browsers you gave, everything seems to work fine with Safari too.

RADIO-TIMETRAVELLER said...

Dr Coyote,

You're welcome, and thanks for the info. I was wondering about Safari.

Bill

Alan David Escobedo said...

Thanks so much for the great pattern Maps of the MW stations

RADIO-TIMETRAVELLER said...

Alan,

You're welcome. Glad you can make use of them.

Best DX,

Bill
RADIO-TIMETRAVELLER