The national transmitter Beromünster took up as new medium-wave transmitting plant of Switzerland on 11 June 1931 its enterprise with a T antenna on two 125 m high transmission towers in Gunzwil. An increase in transmission power and the construction of the Blosenbergturm as a self-radiating transmission tower in 1937 made the signal receivable in many parts of Europe. The two towers of the T-antenna continued to carry a medium wave antenna. In 1962, the west tower was dismantled and rebuilt as a broadcasting tower St. Chrischona for VHF radio and TV. The remaining in Gunzwil east tower served as reserve tower Beromünster.
The regional transmitter Sarnen, which was activated in 1973, replaced the signal of the Beressnower transmitter in the night (ionospheric influence) by means of a co-channel transmitter. The station Sarnen was over the operating building in Beromünster supervised.
The transmitter Beromünster was with the implementation of the Geneva wave plan from 1978 on medium wave on the frequency 531 kHz receivable and also marked the lower end of the official medium wave range. The old frequency was 529 kHz. Between 1969 and 1992, the national transmitter Beromünster was also heard on a second frequency of 1566 kHz. The transmission power was last 180 kW. In 2002 it was determined that the transmitter exceeded the emission limit values for non-ionizing radiation (NISV), which came into force in 2000, at what was then 600 kW, which would have required a costly and costly refurbishment of that power. As the medium wave broadcasting increasingly loses importance, it was decided to switch off the station on December 28, 2008
Source: Wikipedia