the Geneva Frequency Plan of 1975, the facility lost the exclusive frequency of 1586 kHz and the transmitter was retuned to 1593 kHz. Because this frequency is used by other broadcasters, interference problems occurred at night-time in spite of the 800 kW transmitting power. As compensation, station owner WDR was allotted a second medium wave frequency of 720 kHz for daytime transmission only. The 1980s Between 1988 and 1990, the 95-metre mediumwave mast and the 210-metre TV- and FM-mast were replaced by a guyed steel-framework grounded radio mast with a cage aerial for mediumwave in its lower sections. The 1990s In 1993, the 1593 kHz mediumwave transmitter was shut down because some components had been manufactured with PCBs. 720 kHz remained in service, but it was not allowed to use this frequency for night transmission until new regulations were enacted in 1995. At these point there were two radio masts in Langenberg: the 160-metre radio mast for medium wave and the 301-metre radio mast for MW, FM and TV. The shorter mast had to be renovated in 1996; unfortunately, one auxiliary rope tore during this work and the mast collapsed on September 2, 1996. In 1995 the transmission power had to be reduced for ecological reasons. Until the early 1990s the whole radiated power in the AM range was 1000 kW (800 kW on 1593 kHz and 200 kW on 720 kHz), but after 1995 the transmitter was restricted to 85 kW. After the collapse of the 160 metre mast, radiation power of the AM transmitter was reduced to 20 kW. Soon after the collapse of the 160 metre mast, WDR planned a new mast in the form of a guyed grounded steel framework with a height of 170 metres and a cage aerial. The medium wave frequency of 1593 kHz was given to Radio Free Europe. The 720 kHz transmitter was fitted with a directional antenna that minimized propagation of signals westward. Construction of the new mast started in the middle of 1999, but problems delayed its inauguration until July 2000. After the inauguration of the new 170-metre radio mast, transmitter power on medium wave could be once again increased to 85 kW. See also List of masts List of towers List of catastrophic collapses of broadcast masts and towers :de:Rundfunksender Langenberg External links http://www.skyscraperpage.com/diagrams/?b1706 http://www.skyscraperpage.com/diagrams/?b46000 http://www.skyscraperpage.com/diagrams/?b47074 http://www.skyscraperpage.com/diagrams/?b47075 http://www.skyscraperpage.com/diagrams/?b47076 http://www.skyscraperpage.com/diagrams/?b47077 https://web.archive.org/web/20080320144052/http://www.waniewski.de/id283.htm https://web.archive.org/web/20081009134631/http://www.waniewski.de/id147.htm Google maps: Satellite picture Broadcast engineering Radio