Moosbrunn transmitter
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Moosbrunn transmitter
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| Basic data | ||||
| Place: | Moosbrunn | |||
| State: | Lower Austria | |||
| Country: | Austria | |||
| Coordinates: 48 ° 0 '24.1 " N , 16 ° 27' 43.4" E | ||||
| Use: | Broadcasting station | |||
| Accessibility: | Transmitting system accessible by appointment | |||
| Owner : | Austrian Broadcasting Company (ORS) | |||
| Data on the transmission system | ||||
| Wavebands : | Medium wave, short wave | |||
| Radio : | MW broadcasting , KW broadcasting | |||
| Send types: | AM, DRM | |||
| Position map | ||||
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The Moosbrunn transmitter is a large-scale broadcasting system operated by Österreichischen Rundfunksender GmbH (ORS) in the immediate vicinity of Moosbrunn in Lower Austria . The transmission systems are among the most powerful medium and short wave transmitters in Europe.
history
At the end of the 1950s, the Austrian Broadcasting Corporation (ORF) bought an approx. 80 hectare site in Moosbrunn to build a shortwave transmission system. Moosbrunn is about 25 km south of the ORF headquarters in Vienna. The area south of Moosbrunn is swampy with a number of wet meadows. This fact is ideal for the propagation of shortwave signals.
First, five old small transmitters, which had been used to broadcast short-wave programs since 1950, were relocated from the previous location in Bisamberg to Moosbrunn. The transmitters were initially housed in a makeshift barracks, but started regular programming shortly before Christmas 1959.
A newly ordered 100 kW transmitter went into operation on September 4, 1960. Initially, however, this transmitter was operated throttled to 50 kW, as the local power supply was not yet designed for higher outputs. The new transmitter was operated on a likewise newly built trap antenna for omnidirectional radiation. From 1961 rhombus antennas for directional radiation with five directions of radiation overseas were added to the antenna repertoire.
In the fall of 1964, construction work began on a permanent transmitter building. After long-term planning, the building should be able to accommodate up to ten transmitters for a later expansion of the system. The first two transmitters, each with a capacity of 100 kW, finally went into operation in this building on May 1, 1966. The 50 kW transmitter from the temporary facility also moved to the new building and was upgraded to 100 kilowatts. It went into operation on March 5, 1967. At the beginning of 1969, a fourth transmitter with an output of 100 kW went into operation. The five old transmitters from the temporary facility were dismantled.
Another expansion took place in the 1980s: three new, high-performance antenna systems (turntable antenna, double-wall antenna, quadrant antenna) and the first 300/500 kW transmitter from Telefunken went into operation in 1983. This has considerably improved the reception capabilities of Radio Austria International .
In 1984 the dismantled 10 kW transmitter in Aldrans near Innsbruck was brought to Moosbrunn and installed. A second 300/500 kW transmitter from AEG-Telefunken completed the upgrade of the transmitter in December 1987.
At the beginning of 1993, the four old 100 kW transmitters (from 1966, 1967 and 1969) were equipped with new exciters. From this point on, however, two of the old 100 kW transmitters were only available as replacements for maintenance work and as a reserve in the event of a fault. The last major renovation of the system took place in September 2000 and two new transmitters from the manufacturer Thomcast went into operation. These transmitters are equipped with pulse step modulation and allow digital broadcasts in Digital Radio Mondiale (DRM).
The local "Bürgerliste Moosbrunn" considered starting an "initiative against the ORF broadcaster" in 2012.
In December 2014, the operator ORS announced that it would close the Moosbrunn station by 2020 at the latest. These plans were discarded, the transmitter is still in operation (as of May 2020).
Current broadcasts
After the Austrian Broadcasting Corporation (ORF) presented a tight austerity program in 2009, all shortwave broadcasts should initially be canceled. In fact, in 2010 and 2013 some of the broadcasts were stopped and frequencies were discontinued, but the following frequency is still served:
- Towards Europe at 6155 kHz, in the morning in AM (300 kW)
This broadcast is a takeover of the domestic program " Ö1 ". Airtime is rented to various program producers. Most of these are religious broadcasters.
Since May 2, 2005, programs have been broadcast in DRM ( Digital Radio Mondiale ). A transmitter with 50 kW in the 31 m band towards UK (295 °) was used with programs from third-party providers. In addition, the ORF program was broadcast digitally on 6155 kHz in the evening. The BBC also used this digital channel.
Since March 2015, the DARC ( German Amateur Radio Club ) has been using the Moosbrunn shortwave transmitter to broadcast its radio program "Radio DARC" on 6070 kHz with an effective radiated power of 100 kW on Sundays from 11:00 to 12:00 CET.
Transmission technology
Moosbrunn I.
The Moosbrunn I transmitter consists of two THOMCAST TSW2100D transmitters with an output of 100 kW which can also be used for digital radio broadcasting in the Digital Radio Mondiale mode and are fully transistorized except for the output stage.
Moosbrunn II
Moosbrunn II consists or consisted of the following older transmitter systems:
- Four 100 kW transmitters of the type AEG-Telefunken SV2375 (built in 1960/1966/1968, all meanwhile dismantled)
- Two 300/500 kW transmitters of the AEG-Telefunken S4005 type, as shown in the adjacent illustration. Year of construction 1983 or 1987, ready for operation and still in use and a. for the morning broadcast of ORF on 6155 kHz.
- A 10 kW transmitter of the type Continental 416D ( in use at the Aldrans transmitter until 1984 , built in 1975, no longer operational)
- Transmission technology
TSW2100D transmitter rack, Moosbrunn I
Telefunken / AEG shortwave transmitter S4005, Moosbrunn II
Antennas
The largest part of the area is taken up by various transmitting antennas of different types. Depending on the transmission frequency, desired direction of propagation, power and radiation characteristics, the antennas are connected to the respective transmission output stages via antenna switches. The switchover can be done manually or usually automatically as part of the program control.
As of 2006, the antenna system includes the following antennas:
- Small trap antenna for omnidirectional radiation (dismantled in 2011)
- Large trap antenna for omnidirectional radiation
- Rotatable logarithmic periodic antenna
- Quadrant antenna (2 systems for 49 m or 41/31 m)
- Double wall antenna 85 ° and 265 °
- Turntable antenna
- Four rhombus antennas for directional radiation to 56 °, 90 °, 123 °, 175 °, 236 °, 270 ° and 303 °
The four rhombus antennas became superfluous at the end of 2008 due to the shortening of the program by the ORF and were dismantled. Some of the antennas are described in more detail below.
Rhombus antenna
The four rhombus antennas dismantled in 2011 were installed at the beginning of the transmitter system and were suitable for the 31 to 13 m band. This antenna shape, which was most frequently used at the time, was an inexpensive method of transmitting with high transmission power and high directivity. The actual, approx. 260 m long antenna wires were attached to guyed steel truss masts. Two different directional radiation were possible for each antenna system.
Rotatable logarithmic periodic antenna
The logarithmic-periodic antenna is mounted on a steel mast that can be rotated through 360 °. The manufacturer was Rohde & Schwarz . The antenna is designed for a maximum transmission power of 100 kW and can continuously serve wavelengths from 13 m to 49 m. Because of the somewhat steeper radiation pattern, it is used for transmission in the regions of Eastern Europe, the Middle East, North Africa and the east of North America.
Quadrant antenna
The transmitter system consists of two quadrant antennas, each of which enables an almost uniform omnidirectional radiation. The two antennas are designed for different wavelengths of 49 m or 41/31 m and for a maximum transmission power of 300 kW.
Double wall antenna
The double wall antenna , a design of the curtain antenna , consists of two 60 m high steel masts between which a 72.5 m long reflector net is stretched. A similar antenna field consisting of 4 × 4 half-wave folding dipoles is spanned on both sides of the reflector network. The transmission direction can be either 85 ° or 265 °, the antenna is designed for a maximum of 300 kW. The double wall antenna can be used in the 25, 19, 16 and 13 m bands.
Turntable antenna
The turntable antenna is a rotatable, double-walled antenna with two 76 m high masts, a reflector net and 4 × 4 half-wave folding dipoles on one side, and a 3 × 2 half-wave folding dipole field on the other side. The diameter of the track circle is 85 m, the entire antenna weighs 320 tons. A full 360 ° rotation takes approx. 8 minutes.
The turntable antenna can be used on one side for the wavelengths 49 m, 41 m and 31 m. On the other side of the reflector network, the wavelengths 25 m, 19 m, 16 m and 13 m are available. The maximum transmission power is 500 kW.
Web links
- The rotatable directional antenna in 3D
- Kai Ludwig: On the current situation of the Moosbrunn station. For subsequent use by third-party providers and radio amateurs beyond the actual historical broadcast purpose. RBB (radioeins.de), accessed on August 8, 2015
Individual evidence
- ↑ ORF shortwave transmission system will cease operations by 2020 at the latest ( Memento from January 29, 2018 in the Internet Archive )
- ↑ http://www.wabweb.net/radio/sender/moosbrunn2006a.htm Status 2006