Sender Leher Feld
|
Sender Leher Feld
|
|||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 |
|||||||||||||||||||||||||
| Basic data | |||||||||||||||||||||||||
| Place: | Horn-Lehe ( Bremen ) | ||||||||||||||||||||||||
| Country: | Bremen | ||||||||||||||||||||||||
| Country: | Germany | ||||||||||||||||||||||||
| Altitude : | 0 m above sea level NHN | ||||||||||||||||||||||||
| Coordinates: 53 ° 6 ′ 25 ″ N , 8 ° 52 ′ 40 ″ E | |||||||||||||||||||||||||
| Use: | Broadcasting station | ||||||||||||||||||||||||
| Demolition : | January 31, 1999 | ||||||||||||||||||||||||
| Data on the transmission system | |||||||||||||||||||||||||
|
|||||||||||||||||||||||||
| Wavebands : | AM stations , KW stations , FM stations | ||||||||||||||||||||||||
| Radio : | MW broadcast , KW broadcast , VHF broadcast | ||||||||||||||||||||||||
| Send type: | PAL | ||||||||||||||||||||||||
| Position map | |||||||||||||||||||||||||
|
|||||||||||||||||||||||||
The transmitter Leher Feld served from 1951 to 1999 to broadcast the radio and television programs of the radio station Bremen .
precursor
The first transmission systems of the Bremen transmitter, which opened on November 30, 1924, were located in the attic of the telegraph office on Domsheide. The medium wave transmitter worked on a wavelength of 330 m (corresponding to 909 kHz) with a transmission power of 1.5 kilowatts. From the summer of 1926, the wavelength had to be changed frequently due to repeated overlaps and interference from other transmitters. A RS 15 newly developed by Telefunken with an anode voltage of 1500 volts, which was generated by an anode machine in the basement of the building, was used as the transmitter tube .
The transmitting antenna was stretched from a fifteen-meter-high guy mast on the telegraph office across Ostertorstrasse to the courthouse opposite as a double-T antenna. In 1927 the transmitter could be received with a detector receiver in the Bremen area as far as Vegesack, Syke and Delmenhorst. The range for reception with a single-tube receiver extended to Bremerhaven , Rotenburg , Nienburg , Vechta and Oldenburg .
In 1927 the transmission systems were relocated to the Stadtwaage. In the control room there were two Reisz amplifiers VRH 4, a level control device with minimum and peak value display , a telephone exchange cabinet and a converted Morse set that generated the Morse code BRM (for Bremen) as a pause symbol. The power supply was taken over by 12-volt heating and 450-volt anode accumulators .
In order to increase the transmission power and the range, a 90 m high wooden transmitter mast was erected in the courtyard of the Utbremen post office in 1933 . The antenna was stretched inside it, and was closed at the top by an antenna wreath made of bronze tubing . At the bottom the antenna ended in a small house with the transmission equipment. A network of bronze wire was used as lightning protection earthing system, which took up the entire free space. In 1939 the wooden mast was replaced by a steel radio mast after it burned down in a fire caused by a lightning strike.
After the Second World War, Radio Bremen broadcast its first program on December 23, 1945. A mobile medium-wave transmitter of the American military government with 1 kilowatt transmission power served as the transmitter, which was replaced in the following year by a converted German marine transmitter with 2 kilowatts of power. A sixty-meter-high, self-radiating lattice mast on the transmission site on Scharnhorststrasse in Schwachhausen served as the transmitting antenna . The transmission frequency of 527 kHz reached a circle of listeners that went far beyond the country's borders. In 1948 the station was assigned a new frequency of 1358 kHz at the Copenhagen Wave Conference . Due to the shorter wavelength, it no longer had the previous range. An American donation made it possible to start planning a medium wave transmitter with an output of 20 kW in 1950. Since Bremen had been assigned the same frequency as the Tirana transmitter in Albania at the wave conference in Stockholm , shielding had to take place in the southeast. The necessary extended antenna system and a larger transmitter building made it necessary to move to the outskirts.
The transmission systems in the Leher field
broadcast
The Leher Feld transmitter was built in 1951. Until 1999 the transmitter broadcasted the radio programs of Radio Bremen in the VHF, KW and MW range as well as the television program of Radio Bremen.
On October 15, 1951, the new 20 kW medium wave transmitter was inaugurated by the then Bundestag President Hermann Ehlers and put into operation by Mayor Kaisen. An initially 100 and later 110 meters high tubular mast, which was insulated from the ground and served as the main antenna, served as the medium wave transmitting antenna.
On April 1, 1955, the medium-wave antenna system was expanded with an 18 kW VHF transmitter system for the first and second programs. In 1959, the Berlin-Köpenick radio station changed its transmission frequency. When the latter increased its output in 1961, medium wave reception was almost impossible in a wide area around Bremen. The way out was to increase the power of the VHF transmitters to two new frequencies, which Radio Bremen had been granted with 100 kW of radiated power from a 170 m high antenna. In 1962, the necessary construction of a 200 meter high antenna support mast and the expansion of the company building were completed.
In 1961 a shortwave transmitter was put into operation, which broadcast the first program in Northern Europe. A rhombus antenna suspended from four 25-meter-high masts with a main beam direction to south-east Europe existed for the distribution of shortwave broadcasts . At times, the former SFB also sent a shortwave program via this system.
In 1964 a third VHF transmitter (1 kW) with a " guest worker program " was put into operation.
watch TV
In 1954, one of the first television converters was put into operation - initially to broadcast the soccer world championship . The converter installed in the antenna house took over the program from Hamburg via ball reception and emitted it in Bremen with 0.05 kW on channel 23. In May 1962, a television station on channel 23 was having a field Leher image support - radiation power taken from 12 kW in operation, which was increased in 1962 to 50 and 1964 to 100 kW.
The transmission systems
The transmission systems and antenna masts were located on an area of 400 square meters. In the sixties, 12 engineers and technicians worked in shifts in the company buildings to ensure perfect reception of the radio and first television programs. A modulation line transmitted the daily radio program from the broadcasting house to the transmitter building. The transmitter was located in the building with the technical equipment as well as the power supply system, monitoring and antenna switch-over desk, cooling air blower and emergency diesel generator, which can keep the entire transmitter in operation in the event of a power failure. Workshops were used to maintain ongoing operations and repairs. The technical data of the operating devices and the transmitter equipment were continuously checked in a measuring and testing center.
The lower part of the large transmission mast had a diameter of 1.60 meters, which increased from 155 meters in height to two meters. The weight of the mast was approximately 250 tons. Inside, a ladder led to the platforms at 75 and 135 meters high and to the large platform at the top of the mast. With their red and white stripes, the antenna supports, visible from afar, offered orientation for pilots and residents in the Horn-Lehes area for a long time.
The relocation of the transmission systems
In the 1990s, the part of the Hollerland designated as an industrial park was to be developed. It was no longer possible to guarantee electromagnetic compatibility at the location. So it was decided to build a new transmitter in Oberneuland. However, only the 45 meter high transmission mast of the medium wave transmitter was erected there, the planned construction of a 300 meter high transmission mast for broadcasting TV and VHF programs did not materialize. Instead, transmitters were rented on the Bremen telecommunications tower , even if this was less favorable for the broadcasting of Radio Bremen due to the lower height. (At the Leher Feld location, the VHF antennas could be hung almost 100 meters higher.)
In August 1997, the VHF transmitters and the television station “moved” to the television tower in Walle. After a long dispute, the medium wave transmitter now broadcasts the Bremen Eins program with an output of 50 kW from a short MW mast at the new location in the middle of the meadows on Aumundsdamm near the Wümme. On March 13, 2010, this transmitter was switched off for cost reasons.
On the morning of January 31, 1999, the transmitter masts were blown up with great sympathy among the population. The Horn-Lehe West industrial area is located on the site, which is also known as the Haferwende industrial area after the access road.
Overview of technical data
precursor
| date | Location | frequency | Radiant power |
antenna |
|---|---|---|---|---|
| February 11, 1924 | Domsheide telegraph office | 909 kHz | 0.25 kW | Double-T antenna over the Domsheide between the telegraph office and the east tower of the cathedral (later tower of the cotton exchange) |
| May 16, 1926 | 1075 kHz | |||
| November 14, 1926 | 750 kHz (Geneva Plan) |
|||
| May 27, 1927 | 1190 kHz (Lausanne plan) |
|||
| October 14, 1927 | 1103 kHz | |||
| January 13, 1929 | 775 kHz (Brussels plan) |
|||
| July 2, 1929 | 910 kHz | |||
| June 30, 1929 | 827 kHz (Prague Plan) |
|||
| October 10, 1929 | 941 kHz | |||
| December 1, 1929 | 950 kHz | |||
| December 30, 1930 | 1,112 kHz | |||
| November 10, 1932 | 1,120 kHz | |||
| July 10, 1933 | Post site Utbremer Strasse | 1,120 kHz | 1.5 kW | vertical single-wire heater in a 90 m high wooden tower |
| May 14, 1933 | 1,319 kHz (single wave) |
|||
| May 11, 1934 | 1,330 kHz (single wave) |
|||
| December 15, 1944 | Scharnhorststrasse | 610 kHz | 1 kW | L antenna at a height of 25 m between wooden masts |
| December 23, 1945 | 601 kHz | 2 kW | ||
| January 2, 1948 | 527 kHz | 61 m high self-radiating lattice mast | ||
| March 15, 1950 | 1358 kHz (Copenhagen Plan) |
| date | Location | frequency | Radiant power |
antenna |
|---|---|---|---|---|
| February 20, 1954 | Broadcast house | 89.4 MHz | 0.32 kW | 2 yagi antennas on the roof |
| date | Location | channel | Radiant power image |
Radiation power sound |
antenna |
|---|---|---|---|---|---|
| April 2, 1959 | Broadcast house | 23 | 2 kW | 0.4 kW | 2 × 12 Yagi antennas, main beam directions 180 ° and 290 ° |
| August 1, 1959 | 10 kW | 2 kW | 2 × 12 Yagi antennas, main beam directions 180 ° and 290 ° (new power amplifier) |
Sender Leher Feld
| date | frequency | Radiant power |
antenna |
|---|---|---|---|
| October 15, 1951 | 1358 kHz | 20 kW | 109 m high self-radiating tubular mast (initially with a 61 m high lattice mast (see above) for fading out in the direction of Tirana) |
| date | frequency | Radiant power |
antenna |
|---|---|---|---|
| June 1, 1961 | 6,190 kHz | 1 kW | L antenna |
| November 15, 1961 | 10 kW | Rhombus antenna at a height of 25 m, main beam direction NNE |
| date | frequency | Radiant power |
antenna |
|---|---|---|---|
| April 1, 1955 | 89.4 MHz | 18 kW | Tube slot antenna (on a 100 m medium wave mast) plus double dipole 3 × two-field in three-way arrangement, 3 × two-way field in two-way arrangement. Center of gravity 96 m |
| September 1, 1962 | 93.8 MHz (Stockholm Plan) |
100 kW | 3 × 8 dipole groups, height of the center of gravity 174 m, main beam directions 47 °, 157 ° and 267 ° |
| date | frequency | Radiant power |
antenna |
|---|---|---|---|
| November 8, 1951 | 91.8 MHz | 6 kW | Tube slot antenna (on a 100 m medium wave mast) center of gravity 105 m |
| April 1, 1955 | 96.9 MHz | 18 kW | Tube slot antenna (on a 100 m medium wave mast) plus double dipole 3 × two-field in three-way arrangement, 3 × two-way field in two-way arrangement, center of gravity 96 m |
| April 1, 1962 | 96.9 MHz | 100 kW | 3 × 8 dipole groups, height of the center of gravity 174 m, main beam directions 47 °, 157 ° and 267 ° |
| September 1, 1962 | 88.3 MHz (Stockholm Plan) |
| date | frequency | Radiant power |
antenna |
|---|---|---|---|
| November 1, 1964 | 96.6 MHz | 1 kW | Tube slot antenna (on a 100 m medium wave mast) plus double dipole 3 × two-field in three-way arrangement, 3 × two-way field in two-way arrangement, center of gravity 96 m |
| date | channel | Radiant power image |
Radiation power sound |
antenna |
|---|---|---|---|---|
| May 2, 1961 | 22nd | 12 kW | 2.4 kW | 2 × 6 eight fields, center of gravity 75 m, main beam directions 200 ° and 290 ° |
| (Converter) | ||||
| 2nd January 1962 | 50 kW | 10 kW | 2 × 6 eight fields, height of center of gravity 7 m, main beam directions 200 ° and 290 ° (new output stage) | |
| (Converter) | ||||
| October 1, 1964 | 100 kW | 20 kW | 4 × 8 fields of eight, height of center of gravity 205 m, omnidirectional radiation | |
| (Channel) | ||||
literature
- 40 years of broadcasting in Bremen . Published by Radio Bremen, press office, Bremen 1964
- Michael Koppel: Horn-Lehe-Lexikon. Edition Temmen, Bremen 2012, ISBN 978-3-8378-1029-5 .