VLF transmitter Grimeton

Story

The Varberg Radio Station at Grimeton is a VLF transmission facility at Grimeton close to Varberg, in Halland, Sweden. It has the only working Alexanderson alternator rotating armature radio transmitter in the world and is classified as a World Heritage Site. It is an anchor site for the European Route of Industrial Heritage.The transmitter was built in 1922 to 1924; to operate at 17.2 kHz, although it is designed to operate on frequencies up to 40 kHz. The antenna is a 1.9 km flattop wire aerial consisting of eight horizontal wires suspended on six 127-metre high freestanding steel pylons in a line, that function as a capacitive top-load to feed energy to six grounded vertical wire radiating elements.The Grimeton VLF transmitter location is also used for shortwave transmissions, FM and TV broadcasting. For this purpose, a 260 metre high guyed steel framework mast was built in 1966 next to the building containing the 40 kHz transmitter.Until the 1950s, the Grimeton VLF transmitter was used for transatlantic radio telegraphy to Radio Central in Long Island, New York, USA. From the 1960s until 1996 it transmitted orders to submarines in the Swedish Navy.