QTH on VHF and above

When I started using XLog on my Debian system to log radio contacts or stations I had listented to, I noticed a field "Locator" and a preference "QTH Locator" so I did some looking to find out what they may be.

In my searching I learned that for VHF and higher frequencies a few location exchange schemes were developed to help contesters quickly communicate their locations.

The first ideas were developed for contesters in Europe and were adapted to other regions of the world, but the values would repeat themselves. A couple of names for these drafts were the QRA Locator and QTH Locator systems.

In 1980 a group of European VHF managers met in Maidenhead, UK to discuss a new locator system that would have globally uniquie values. The system has been termed the Maidenhead Locator System and was adopted by IARU Region 1 at the first of 1985.

The Locator system divides the globe into 324 Fields, each one 20 degrees longitude by 10 degrees latitude labeled with the letters AA - RR. Each Field is divided into 100 Squares, each 2 degrees longitude by 1 degree latitude and labeled with the digits 00 - 99. Finally each Square is then divided into 576 Subsquares of 5 minutes longitude by 2.5 minutes latitude and labeled with the letters AA - XX.

A Locator of just the Field and Square, such as DN41, will give your location within 2 degrees longitude and 1 degree latitude or about 100 miles in the middle of the U.S.A. Adding the final two letters, such as DN41br, gives your location within a few miles.

You can use a good map, a GPS device, a call to your local city surveyor or a search on the internet to find the latitude and longitude of your city. Then you can plug that location into one of several online Maidenhead Locator systems. Make sure it's the new system. There are some QTH Locator calculators floating around that may give you the wrong code since the two systems are not 100% compatible.

If you're not sure you got the right latitude and longitude, you can try looking it up at maps.google.com and doing a search for the location, eg 41.73556,-111.83361.

http://www.arrl.org/locate/gridinfo.html
http://www.arrl.org/locate/grid.html
http://www.jonit.com/fieldlist/maidenhead.htm
http://homepages.tesco.net/~a.wadsworth/gridmaps.htm
The ARRL Operating Manual page 4-3.