How do I find my location?? I wanna get coordinated!

Filing Your Application? Get your coordinates!

When you go to the FCC webpage, you will be asked to fill in the exact location of your proposed antenna. You can determine the exact geographic coordinates and elevation of your proposed transmitter using on-line resources. The Prometheus Quality Assurance Commission (PQuack) has thouroughly testing these resources and they appear to be reliable and very useful!


Geographic Coordinates
You can use our RFree software to find and check coordinates for an LPFM station and much more, or use the method below to use standard web tools. You can also use a smart phone, GPS unit, or Google Earth.

This method works as of January 2016...

  1. Go to Google Maps
  2. Navigate to your location and zoom in
  3. Switch to the satellite view (lower-left corner) and zoom in some more if needed
  4. Place your mouse at the desired location for your antenna, right-click and select What's here? from the menu. --OR-- left-click on the desired location.
  5. The pop-up at the bottom of the screen has the coordinates on the last line. Click on them.
  6. Now the coordinates are present in the location search box looking like this: 39.948273, -75.218727 and a bit below that in degrees-minutes-seconds format like this: 39°56'53.8"N 75°13'07.4"W. These coordinates are precise to about 10 feet.
  7. Save these numbers! If you are simply communicating a location with someone, like Prometheus, you're done, however...
  8. Filling out your own FCC application for FM or LPFM? You're Not Done Yet! For FM and LPFM radio stations, the FCC uses an older coordinate system called NAD27 whereas most coordinates including Google Maps coordinates, use the newer NAD83 system. You don't have to understand all of that except to know that you have to convert the coordinates to NAD27 before you can use them on an FCC application, and that's probably the ONLY place you'll use that form of the coordinates. If you don't convert them, your FCC application could be 300-feet off!
  9. To convert your coordinates from NAD83 as you got from Google Maps, to NAD27 as required by the FCC, visit the government's NADCON converter.
  10. For the "direction of conversion:" you want to select "NAD83 to NAD 27".
  11. Paste or type in your coordinates from before. It is easier to use the first format than the second one, because if you paste the degrees-minuetes-seconds format, you'll have to remove everything which isn't a number.

    ALERT! If you use the numerical form (39.948273, -75.218727) you must change the sign of the longitude, so you would in this case enter 39.948273 as the latitude and 75.218727 (not -75.218727) as the longitude. The NADCON web page sorta tells you that, but who reads the fine print?!

  12. After the conversion, the web page will look something like this:
                          North American Datum Conversion
                                 NAD 83 to NAD 27
                            NADCON Program Version 2.11
                               Transformation #:    1        Region: Conus          
                                        Latitude                 Longitude
      NAD 27 datum values:           39 56 59.79384           75 13  8.44975
      NAD 83 datum values:           39 57  0.20000           75 13  7.10000
      NAD 27 - NAD 83 shift values:        -0.40617                  1.34975(secs.)
                                          -12.527                   32.040  (meters)
      Magnitude of total shift:                         34.402(meters)
    It is a good idea to print and/or save this page!

    The converted coordinates are listed in the "NAD 27 datum values" line, and that's what you'd put on your FM or LPFM FCC application. In this case, if we entered the NAD83 coordinates by mistake on the FCC form, we'd be 34.4 meters or 113 feet off!

But How High is It?
Your FCC application also asks how high the ground is at the location of your antenna. Google Earth is one way to determine the elevation, and here's how to get it from the U.S. Geological Survey.
  1. Go to the Elevation Point Query Service
  2. Enter your longitude as obtained from Google into the "X:" box (-75.218637)
  3. Your latitude from Google goes into the "Y:" box
  4. Select Units: Meters and Output: XML
  5. Click [Get Elevation]
  6. You can pick out the elevation from the XML code, here's what it might look like:

    <USGS_Elevation_Point_Query_Service><Elevation_Query x="-75.218637" y="39.950053"><Data_Source>3DEP 1/3 arc-second</Data_Source><Elevation>29.713018<</Elevation><Units>Meters</Units></Elevation_Query></USGS_Elevation_Point_Query_Service>

A word about antenna height

Obviously, the height of the location that you build your transmitter on is important. If you have a choice, get the antenna up as high as possible. It should be noted that while not optimal, perfectly adequate coverage can be had from a twenty or thirty foot antenna located on a residential rooftop, all other things being equal. Depending on the antenna you choose, it can look less obtrusive than even a standard TV reception aerial.

You can find out much more in our Transmission Toolkit.

A word about location

Also keep in mind: While it is best and cheapest to have your studio and transmitter at the same site, nothing needs to be at the transmitter site except for the transmitter, electric power, the antenna, and some sort of receiver for broadcast audio- either via telephone lines or by radio link.

Check out Sound Around Town for more.