N9SSA MPW Calculator V2.5. Home Page. DXplorer. Maidenhead Locator System. The Maidenhead Locator System is a geographic co-ordinate system used by amateur radio operators.
Dr. John Morris, G4ANB, originally devised the system, and a group of VHF managers, meeting in Maidenhead, England in 1980, adopted it. HF Propagation and Solar-Terrestrial Data Website. 2137. PSK Reporter. Find Maidenhead locator or QTH grid square.