Standing on the summit is the North Hessary Tor transmitting station, an FM radio and television transmitter which uses a 196 metres (643 ft) high guyed mast. It was built by the BBC in 1955 when a transmitter was needed to introduce 405-line television into Devon. It now carries a small UHF TV transmitter which serves Princetown and Dartmoor. FM radio transmissions began in 1956 and cover most of Devon and eastern parts of Cornwall.
References
^Brewer, Dave (2002). Dartmoor Boundary Markers. Tiverton, Devon: Halsgrove. p. 34. ISBN1-84114-172-0.