What are Grid Squares or Maidenhead
Locators? - The basics
We all know and
understand co-ordinates given in degrees minutes and seconds using
latitude and longitude. These co-ordinates are good and very
accurate but tedious to relay by radio.
This is where grid squares come in. Very basically, grid squares are
very small rectangles calculated from your normal latitude and
longitude co-ordinates. The normally consist of a combination of six
letters and numbers. ie. KF37wa
This six character combination is simple and quick to relay over the
radio. Its not quite as precise are the normal co-ordinates given in
degrees minutes and seconds, but is accurate enough for amateur
radio contest or award requirements.
What are Grid Squares or Maidenhead
Locators? - A bit more detail
The "Maidenhead QTH
Locator System" is the official QTH locator system adopted by the
IARU (International Amateur Radio Union) and replaces the old "QRA
Locator System". The new system is used primarily by the Amateur
Radio Service and uniquely defines any given point on the surface of
the globe to within an area of 5 minutes of longitude by 2.5 minutes
of latitude. This is achieved using a six character reference,
although this can be extended to eight characters, with a
corresponding increase in resolution.
Some GPS (Global Positioning System) receivers can be programmed to
display Maidenhead QTH Locators directly. The main disadvantage of
the old QRA Locator System was that several points on the earth's
surface had the same reference. When first introduced, this did not
present a problem, but as the equipment and operating techniques
improved, so did the ranges achieved, which gave rise to possible
ambiguities.
The Grid Locator System is primarily used on the VHF bands, the six
character groups
forming part of contest exchanges. They are also often used during
normal QSOs to
pin-point a stations location. There is also considerable interest
in "collecting
squares" (the first four characters of the Grid square, e.g. KF37).
How big is a Grid Square?
To answer that properly we must break
down the Grid Square into three parts. We'll use KF37wa as
and example.
- The first two characters
represent a rectangular area 20° wide and 10° high. KF
- If we include the two numbers
next the rectangle becomes 2° wide and 1° high. KF37
- Once we include the last two
letters the rectangle becomes very small and represents only
5.5km x 5km. KF37wa
How can I calculate my locator?
Very easily, simply use the
calculator below to do all the hard work for you. Once you know your
grid locator you can add it to the national database by looking up
your callsign in the online call book
and then adding your Grid Locator from there.
