The LORAN-C transmitter Rantum is a transmission facility for LORAN-C on the German island Sylt near the village Rantum at 54°48'30″N, 8°17'37″W(). It was established in the 1960s, initially using a guyed steel framework mast with a triangular cross section, approximately 190 metres tall. In 1996 this mast was replaced by a 193 metre high mast of the same type but of a better mechanical design. The new mast is, as its forerunner, insulated from ground and has a triangular cross section. The construction, weighing 65 tons, is guyed in 4 levels at 60.52 m, 120.87 m, 154.95 m and 190 m.