Capital Radio (pirate)

[2] The pirate radio station on board the King David began transmitting test transmissions off the Dutch coast on 14 June 1970, at 269 metres, 1115 kHz.

[citation needed] The ship was fitted with a 10-kilowatt transmitter that had allegedly belonged to Radio 270, and was equipped with an unusual horizontal loop antenna.

These antenna types produced strong skywaves that could potentially cause interference to distant stations, especially at night.

[citation needed] Once the station went on air the loop antenna did produce an efficient signal, covering large parts of the Netherlands, Belgium and eastern England although the transmitter was only operated at 1 kilowatt.

However, if the ship listed too far in heavy seas one side of the loop could make contact with the water, causing the transmitter to momentarily short out.