Anthorn Radio Station is a naval and government radio transmitting station located near Anthorn, Cumbria, England, overlooking the Solway Firth, and is operated by Babcock International (with whom former operators VT Communications are now merged). It has three transmitters: one VLF; one LF; and an eLORAN transmitter. It is on the site of the World War II military airfield which was operated by the Fleet Air Arm as HMS Nuthatch. RNAS Anthorn John Laing & Son began building an airfield at Anthorn for the Fleet Air Arm in late 1943, and Royal Naval Air Station, Anthorn, was commissioned as HMS Nuthatch on 7 September 1944, with three tarmacadam runways. It was the base of No. 1 Aircraft Receipt and Despatch Unit (No. 1 ARDU), which had the job of receiving aircraft fresh from manufacturers, modifying them to Service standards and despatching them to operational squadrons, with the unit specialising in the Vought F4U Corsair, Supermarine Seafire, Fairey Barracuda and Fairey Firefly types. No. 1 ARDU continued to operate from Anthorn following the end of the Second World War, while a number of Fleet Air Arm Squadrons were also based at the airfield in the immediate post war years. The airbase shut down in March 1958. The present road to Cardurnock runs partially along the airfield perimeter track. Several firing butts, for synchronising aircraft machine guns, can still be seen on the seaward side of the road. VLF transmitter The VLF transmitter is used primarily for transmitting orders to submarines and transmits on 19.6 kHz with an output power of 550 kilowatts. Its callsign is GQD. VLF transmissions are relatively unaffected by atmospheric nuclear explosions and Anthorn was once part of the link between Fylingdales early warning radar, North Yorkshire, and the United States' air defence system. A large part of the site is taken up by the VLF transmitter's large trideco wire umbrella antenna. This consists of a central mast with 6 vertical wire radiators suspended from its top fed at the base of the mast, attached to 6 rhombic-shaped 2148 ft long horizontal multiwire toploads which radiate from the central mast at angles of 60°, supported by 12 surrounding masts, giving the antenna the shape of a 6-pointed star when seen from above. The cables supporting the endpoints of the wire antenna carry a load of 31 tons and are attached to computer controlled winches which automatically adjust the