Marnach transmitter was a broadcasting facility of RTL near Marnach in the commune of Munshausen, in northern Luxembourg. The Marnach transmitter was built in 1955 for improving the transmission of the English-speaking program on 1439 kHz (later 1440 kHz), which was transmitted from 1951 with an omnidirectional antenna from Junglinster, to the British Isles and for a better transmission on this frequency to Germany at daytime. Therefore, it was given a directional antenna with a switchable directional characteristic pointing North-northeast towards the Rhine-Ruhr area, Germany's most populated area, and West-northwest in the direction of the UK. This antenna was implemented in form of a directional antenna consisting of three ground-fed 105-metre tall guyed mast antennas arranged in the form of an isosceles triangle with a 90 degree angle.