The LORAN-C transmitter Jan Mayen is a LORAN-C transmission facility on the island of Jan Mayen at 70°54′51″N 8°43′57″W / 70.91417°N 8.7325°W / 70.91417; -8.7325Coordinates: 70°54′51″N 8°43′57″W / 70.91417°N 8.7325°W / 70.91417; -8.7325. The LORAN-C transmitter Jan Mayen uses as antenna a 190-metre high (625 ft) guyed mast.
This mast was built as replacement of a 190.5 metre tall mast, which collapsed in a storm on 8 October 1980 as the result of too low tension on the guy wires. The guywires were adjusted by personnel from the USCG who mixed up pounds and kilograms.