Nauen Transmitter Station
At the end of World War II, invading Russian troops dismantled and removed the transmitting equipment.
During the early years of the 20th century after Marconi's 1901 transatlantic radio demonstration, industrial nations began building networks of powerful longwave transoceanic radiotelegraphy stations to communicate with other countries and keep in touch with their overseas colonies.
The transmitter worked at frequencies of 75 – 100 kHz with a radiated power of around 10 kW, and the station could be received at a range of about 3,500 kilometres (2,200 miles).
[4] This was an early continuous wave radio transmitter technology invented by Georg von Arco similar to the Alexanderson alternator.
[4]: 295 After the beginning of World War I in 1914, the station became very important because the transatlantic cables leading to Germany were cut by the British Navy.
During the war, the station was run by the German Admiralty, which used it for military communication with its fleet as well as commercial radiotelegraphy traffic.
The British Radio Intelligence Service devoted much effort into intercepting and decoding encrypted military communications from the station during the war.
[6][7] The rotor's 240 teeth (magnetic poles) generated 1200 amps alternating current at 450 volts and a frequency of 6 kHz.
[8] The large doubler transformers, although 90% efficient, required a powerful forced-oil cooling system to remove the 40 kW waste heat.
[9] In 1918 in World War 1 US president Woodrow Wilson transmitted a request for surrender to Nauen from the alternator station at New Brunswick, New Jersey.
A new transmitter building designed by Hermann Muthesius was erected in 1920, an Art Deco style cathedral-like structure to give space for more high power transmitting equipment.
In the 1920s long distance radio communication shifted from the longwave to the shortwave bands with the discovery of the skywave (skip) propagation mechanism.
Between 1971 and 1981 three 500 kW superpower shortwave transmitters were installed, feeding 23 high gain curtain antennas positioned to broadcast to politically important countries.
In 1964 two German companies built one of the first prototype rotating shortwave broadcast antennas nearby at the Dechtower dyke, which was used until the end of the Cold War.
This consisted of a 70 metre tower supporting two reflective dipole arrays weighing 40 and 70 tons covering 5.8 to 18.8 MHz that could be rotated 360° and tilted in elevation from horizontal to 30° to adjust to changing ionospheric skywave propagation conditions.
On 3 October 1990, the day the GDR reunified with the Federal Republic of Germany, all transmitters were switched off and the station was provisionally transferred to German international shortwave broadcaster Deutsche Welle.
