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Transmitter IsmaningThe Transmitter Ismaning is a large radio station inaugaurated in 1932. Until March 16th, 1983 there was a wood framework transmission tower built in the thirties. This tower carried until 1969 an antifading aerial for mediumwave. From 1969 to 1977 it carried transmission aerials for FM radio. In the last years of its existence, the tower, which was nicknamed "Bavarian Eiffel Tower" had no function. The transmission facility Ismaning is used for transmitting the first program of the Bavarian Broadcasting company on the medium wave frequency 801 kHz (transmission power 600 kilowatts until 1994, now 100 kilowatts) and for allprogrammes of the Bavarian Broadcasting company in the FM range. Until 1994 there was also a transmitter of AFN at Ismaning. For the AM transmissions a 171.5 metre high guyed steel tube mast is used. This mast is insulated against ground and is designed as fading reducing transmission aerial with multipl feeding. Therefore it is separated in 56 metre and 117 metre height by an insulator. Restrictions of the waveplan of Geneva required a minimum of radiation in direction Northeast, in order to reduce interferences of the transmitter Sankt Petersburg, Russia, on the same frequency, if transmission power is 600 kilowatts at night. Therefore in 1978 a 71 metre high guyed steel-framework mast, which is insulated against ground, was built in 1978 near the mast upper mentiond. Because a power reduction toward Northeast is not necessary with a transmission power of 100 kilowatts, this mast is now obsolete, but it is still there. As back-up aerial a 105 metre high, guyed steel framework mast was built in 1947 close to the transmitter building. This mast, which was originally used for transmitting the program of AFN was until 1969 126 metre high and carried from 1958 to 1969 aerials for FM transmissions. Restriction by the waveplan of Kopenhagen had the result, that the mediumwave transmitter of the Bavarian broadcasting company had to work with directional radiation with minimum toward Northeast after 1951 at nighttime. This type of radiation was not possible with the aerial on the wood framework tower and a directional aerial consisting of two insulated guyed radio masts with a height of 94 metres had to be built. This aerial was until 1969 for transmitting the program of the Bavarian broadcasting company during nighttime in service. After 1969 it was used until its shutdown in 1994 for transmitting the program of AFN on 1107 kHz. In difference to the time before 1969 omnidirectional radiation was used. One mast was used and the other one was a spare unit. As aerials for shortwave transmissions of the Bavarian broadcasting company there are a dipol aerial, built in 1976, which hangs on two guyed steelframework masts with a height of 35 metres and a winkle dipole which hangs on three guyed steelframework masts with a height of 55 metres. The winkle dipol aerial went in service in 1980. For FM-broadcasting transmission there is a silvery grey guyed steel framework mast with dipol arrays on its top near the station building. This mast, which was built in 1977, has a height of 100 metres and is the only mast at the transmitter Ismaning, which is grounded. The Voice of America run until 1994 near the station of the Bavarian Broadcasting company a large shortwave transmission facility, which is nowadays completely demounted. still in operation is the medium wave transmission fcility of the Voice of America. It consists of four guyed steel framework masts, which are insulated against ground. These masts were built in 1949 and renovated in the ninties and allow the realisation of a directional aerial with changable directional characteristic. List of masts
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