Grid squares
A Maidenhead locator, or grid square, names a cell on the map rather than a point. Amateur radio uses them constantly: a net asks for yours, a contest exchange is one, and a DX spot often gives you a locator and nothing else.
APRS Connect has a Grid square screen in the drawer, which opens when you swipe up on the tab bar. It does two things, both free, and both entirely on the phone: no account, no lookup service, and nothing sent anywhere. It works with the radio off and no signal.
Your own grid square
The top of the screen is your six-character locator, large enough to read out and with a COPY button beside it. Under it, the place the square covers, once the phone has reverse-geocoded it.
It is calculated from the best position the app has:
- Where the phone is now, when you have allowed the app to use your location. The screen asks the first time you open it, because that is the question it exists to answer.
- The last position you beaconed, otherwise. A station that beacons a fixed position still knows its own square without any location permission at all.
If neither is available the screen says so rather than showing a locator it has guessed.
Distance and bearing
Below that is one box. Type either:
- A grid square of four, six or eight characters, in any case.
JN58tdandjn58TDare the same square. - A callsign this app has heard with a position. Base callsigns and SSIDs both work:
N0CALLanswers with that exact station when it has been heard, and otherwise with whichever of its SSIDs beaconed most recently.
The answer is the distance, the compass point, and the bearing in degrees true, which is the number you need if you are turning a beam.
Distances follow the units setting, so the same contact reads in miles or kilometres to match the rest of the app.
How exact the answer is
The screen says which of two things it measured, because they are not equally good:
- To a station's own beacon: measured to the position they actually transmitted.
- To the middle of a square: a locator is a cell, not a point, so the distance is quoted with the slack that implies. Four characters is a cell about 100 km (60 miles) across; six is about 5 km (3 miles); eight is a few hundred metres. The screen prints the give-or-take in your own units rather than making you convert it.
Two characters is a field, roughly 2,000 km (1,200 miles) across. The screen refuses to measure to one and asks for at least four characters, because a distance to the middle of a field is not a distance to anywhere.
On a map
Show on the map, under your own square, opens a map with the grid drawn on it. Your square is outlined and named, with a dot where you are inside it. If you have looked up a square or a callsign, that one is outlined too, with a line from you to it. The line is the great circle, the path the distance and the bearing describe, so to another continent it curves.
Every cell on the map is named. Zoomed far out the names are two-character fields; closer in, four-character squares; closer still, six-character subsquares.
Tap any cell to look it up. Its locator appears at the top of the map with the distance and bearing from you. FIT brings both ends back into view, and ◎ takes the map back to your own square.
In the browser and desktop apps on a wide window, the map is beside the Grid square screen instead, and a click on it fills in the box.
From the main map
Long-press anywhere on the map and the sheet gives you that point's locator alongside its coordinates, each with its own COPY button. That is the quickest way to get the square for somewhere you are not, such as a summit, a park or a field day site.
Where else grid squares appear
APRS OTA hosts announce themselves with a locator, and the OTA screens use it to calculate range and bearing to an operator whose beacon has never reached you. That is most of them, since a station 3,000 km away has no path to your radio. The arithmetic is the same as this screen's.
Last updated 9 October 2026