Forty-seventh edition of the N&O column / Spooks newsletter

(Date: Mon, 01 Apr 2002 18:19:51 +0200)

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Short-wave transmitter sites

Shortwave transmitter sites in Greater Frankfurt am Main area by Andreas Erbe and Wolfgang Bueschel

The city of Frankfurt is worldwide knows as a city of bankers. With its about 650,000 inhabitants, it attracts a lot of tourist visitors each year, though there is nothing particular to visit - in contrast to many other towns in Germany. The radio history of this part of Germany is not well documented therefore a part of it, namely the chapter of shortwave transmitters, will be discussed here. The AM-transmitter sites other than shortwave will be mentioned only, and the history before 1945 will not be dealt with at all. Why can this be of interest to the number station enthusiast? On the one hand, famous DFC37 and DFD21 originated from that area, and E5 sent out some transmissions there.

Historic Background

It all started with the American occupation of a big part of what is today South Germany after World War II ended in 1945. And of course at this time, there was a need for every power present in Germany to communicate with the homeland. Since the main transmitter sites of Germany where located around Berlin, associated with the names Koenigs Wusterhausen and Nauen, the Western powers had less chances to take over old transmitter equipment.

The British zone in North Germany had the transmitters in Elmshorn near Hamburg. So there was a base for shortwave communication. On the other hand, in the American zone only around Munich a few broadcast transmitters were left. And to communicate with the American mainland, shortwave communication sites were urgently needed. Being an economic centre for a long time, Frankfurt and the surrounding area was well suited to house these new sites. And Frankfurt was a broadcasting centre, too.

Transmitter sites of Hessischer Rundfunk

The regional public broadcaster for the state Hessen is Hessischer Rundfunk (HR). HR was set up in 1948 as part of the new federal radio system in West Germany. It was the successor of Radio Frankfurt which started operating in 1945 under US American control [1]. All over West Germany, the newly formed regional broadcasters took over control of their transmission facilities from the German Post.

In those days, HR operated an own shortwave transmitter. This one started broadcasting in late 1947. The 1-kW-unit made by Lorenz operated only until 1954, when it was dismantled [2]. The frequency was 6190 kHz (48.47 m) which was later used by Radio Bremen till 1996 and at present is used by Deutschlandfunk from the site at Berlin-Britz. The transmitter was located at the site Heiligenstock in North Frankfurt, Friedberger Landstrasse 525 at 08E43, 50N09. This facility housed also a medium wave transmitter of HR. The original transmitter (synchronized network on 1195 kHz with 25 kW) from 1935 was severely damaged in March 1945. A provisional repaired facility served for Radio Frankfurt after the war was over. AFN also used the Heiligenstock site for radio programmes. This part of the story will be presented later.

August 23rd saw the launch of the Lorenz-reconstructed original transmitter with a power output of now 100 kW serving until October 15th, 1967, when the Heiligenstock site was closed. The MW antenna installation consisted of four 121 m pipe masts. The site operated on a synchronized network with other sites in Hessen. In those days, Radio Frankfurt and later Hessischer Rundfunk used 1439 kHz, while AFN was on 593 kHz until the Copenhagen HF plan became effective March 15th 1950. The HR moved from 1439 to 593 kHz while AFN left 593 kHz for the new 935 kHz with 10 kW. For the close-down of transmissions from the Heiligenstock site, the official reason was that the city of Frankfurt wanted to build flats on the ground where the facility was located, and therefore asked HR to look for a new site in the late 1950s. But up to now, no new building can be seen on the ground of the former transmitter facility. Another reason was the old transmitter having problems operating 24h a day - so a new transmitter to be planned anyway. October 16th, 1967 saw the start of transmissions from the newly erected site in Weiskirchen-Rodgau, located 15 km south west to Frankfurt. Two masts, each of which 126 m high, were erected there. This site still operates on 594 kHz. Some pictures and historical information in German can be found on Hansjoerg Biener's website [3].

Sites of Deutsche Bundespost (DBP)/Telekom

In West Germany, the broadcast transmitters where handed over from the post to the regional broadcasters in 1946/1947. Later almost all broadcast transmitters were operated by the broadcasters. Exceptions where Deutsche Welle and Deutschlandfunk later. Both used transmitters operated by the West German Post, Deutsche Bundespost (DBP). All utility service transmitters where operated by DBP. As the British and US zone of Germany united to a unified economic "bizone" in 1946, there was also only one headquarter of the Post, which was located in Frankfurt. This was one reason why new communication capabilities where needed in the Frankfurt area. Subsequently, three communication facilities where build in the end of the 1940s in Hessen. One was located at Mainflingen. This one only operated on longwave and later housed broadcasting MW transmitters. The other two facilities at Frankfurt-Bonames and Usingen-Merzhausen were intended for shortwave communication. One transmitter site was needed to improve reception of news agency transmissions from the coast station Norddeich Radio (North Sea coast) in South Germany. So a place near Mainflingen, 25 km southeast to Frankfurt was chosen to set up a new longwave transmitter. The first transmission hall was erected in 1950.

The first user was the press agency, and over the years, the meteorological service was the main user of this facility. Today the site today is more famous for the time signal station DCF77 on 77 kHz. Also broadcasters Deutschlandfunk and Evangeliumsrundfunk used and still use the facility [4]. The Mainflingen site never housed shortwave transmitters. The building-up of the transmitter facility at Frankfurt-Bonames in the north of Frankfurt started in late 1947. The first transmitter hall was set up in a former casino building. It housed 11 Lorenz-made shortwave transmitters. Six 20-kW units served as telegraphy transmitters, four 20-kW-units were used for single-sideband-(voice)-transmissions. An additional 5-kW transmitter was also installed. From 1950 till 1952, a power supply backup was erected, and the second transmitter hall was build up. This hall was equipped with 6 Telefunken 20-kW-transmitters, four 5-kW Lorenz transmitters and in addition with 11 small 1.2-1.5-kW-units made by Lorenz. Two of these transmitters were longwave transmitters, whose purpose remains unclear. In the mid 1960s, the small transmitters and two of the 5-kW units were dismantled and replaced by 9 modern automatic Telefunken transmitters with a power output of 20 kW. Most aerials on the Bonames site were rhombic ones, carried by 20 to 30 m high masts. Most of them beamed their signals to North America. There were also some nondirectional vertical antennae, quadratic dipoles and two logperiodics. The area of the Bonames site was located in densely populated area, and with the city of Frankfurt growing it was impossible to expand the site. Therefore it was decided to close this facility. Transmitter hall 1 ceased operation in 1968. Most of the transmitters were scrapped and a few moved to North Germany to the site of Elbe-Weser-Radio. The modern Telefunken transmitters installed at the beginning of the 1960s in hall 2 were moved to Usingen. Most of the transmitters and antennae were scrapped, some moved to Usingen. Others were transferred to Elmshorn near Hamburg. In 1972 the complete Bonames site was silenced forever. Only administrational tasks remained there [4]. The third site of DBP to be mentioned here is in Usingen-Merzhausen. The town of Usingen is located in the Taunus mountains 25 km north to the inner city of Frankfurt. More information can be found at Usingen's internet site [5]. A communications facility was erected at a former army airfield. The West German post leased the area for 30 years beginning 1953 for this purpose. The first task was to clear the airfield from the remaining bombs of World War II. This took around 2 years. In late 1955 the set-up of the transmitters started as they should be operational by Christmas 1956. In 1958, fourteen 20 kW and four 100-kW-transmitters where operational, and the first transmitter hall was fully equipped. Most antennae where rhombic antennae at that time. With the growing traffic on shortwave, an expansion of the station in Usingen was planned, and the building of a second transmitter hall started in 1965. Between 1967 and 1968 ten remote controlled transmitters with a power output of 20 to 30 kW were installed. With the closure of the Bonames site 9 modern remote controlled automatic transmitters came to Usingen in 1970. In May 1976, 37 transmitters and 43 aerials operated in Usingen at its high. The new era of satellite communications started for West Germany in 1965 with the set-up of the earth station in Raisting near Munich. The closure of the shortwave facility in Bonames must be seen in this context too. The decline of shortwave activity lead to the dismantling of shortwave transmitters beginning in 1976. The last hand-operated transmitters were removed in 1982, and only 3 large rhombic antennae of the original 26 remained. By the end of 1989 all shortwave services were carried on by the site Elmshorn near Hamburg. Usingen became a famous satellite earth station instead. The first parabolic antenna as uplink transmitter was inaugurated in 1979. The building up of this antenna took about two years. Nowadays, more than 15 satellite antennae are operational at the Usingen site and no shortwave transmitters are left [7]. Information about the satellite earth station can be found on the internet pages of Deutsche Telekom [6]. So with the political changes in Europe in those days also the last commercial shortwave transmitter site in the Frankfurt region was closed.

Site of Deutsche Nachrichtenagentur (DENA)

Immediately after World War II in each zone of Germany new news agencies were founded. The British zone got the DPD (Deutscher Pressedienst), in the American zone DENA (Deutsche Nachrichtenagentur) was founded and in the French zone the new SUEDENA (Sueddeutsche Nachrichtenagentur) sprang into life. Those three joined to form the West German "Deutsche Presseagentur" (DPA). The name of DENA, this time as Deutsche Nachrichten GmbH, remained present in the DPA as an affiliate, that operated services for the DPA. Deutsche Nachrichten GmbH was closed in 1997 and is now a company in liquidation [8]. DENA operated a transmitter for DPA on a neighbouring area to the HR site Heiligenstock, located half way between Frankfurt and the town of Bad Vilbel north to Frankfurt at Friedberger Landstrasse 645. It had a longwave transmitter to broadcast the DPA news service in German. This service seemed to have operated since the end of the 40s until the end of the 60s. Klingenfuss gives in his "OldFreq"-list a callsign of DCF 39 for fax transmissions on 139 kHz [9]. But also some shortwave transmitters of 20 kW transmitted DPA's English service worldwide in RTTY. It is reported that also the Japanese news agency JIJI Press was transmitted from DENA-transmitter Bad Vilbel. The site operated until the mid-1980s. To date, no literature source has appeared giving details of this facility. That's why we have to rely on the "collective memory" of the hobbyists. Today, the former transmitter hall seems to house a flat a family, and one part of the area is used for the graveyard of Bad Vilbel. The name "DENA-Sender" however is still present on the city maps of Frankfurt. It can e.g. be found in a map about the housing estates in Frankfurt [10].

American transmitter sites

With the presence of US troops in the region also American transmitter sites have been built. American Forces Network (AFN) started medium wave transmissions via a 300 watt transmitter in April 1945, from IG-Farben sky scraper in the northern suburbs of Frankfurt am Main on 593 kHz. From June 1st, 1945 Radio Frankfurt Heiligenstock site was used for the AFN Frankfurt program via a provisional transmitter. As already mentioned, AFN changed to 935 kHz in 1950 with the new HF plan. This channel was in use until the new site in Weisskirchen was finished, some time between 1950 and 1952. Since then, AFN can be heard on 873 kHz in the Greater Frankfurt area. The transmitter site is located north of Frankfurt in Weisskirchen, part of the town Oberursel. The site just got a new 150-kW-transmitter in 1994. In 2000 the site became famous as a lightning damaged the set-up. More information including some pictures can be found at Hansjoerg Biener's web site [3]. But in addition also a military site exists south to Frankfurt which was used for shortwave communication maybe by the US Air Force. The site is locates between Langen and Moerfelden-Walldorf, 15 km south to Frankfurt in a former forbidden zone. We do not know anything about the transmitters there, but there are several logarithmic-periodic and vertical antennae that are definitely intended for the use on shortwave. And there is a directional link connection to apparently the military part of Frankfurt's international airport. The real owner and what is transmitted there is subject of speculations. One user may be the US military - the site is not even listed on good maps.

Number stations

Up to now some information has been presented about the transmitter sites in the Frankfurt area. What can the number station enthusiast do with this? There were several West German number stations: then BND family around Papa November and the Two-Letter-Stations as well as DFC37 and DFD21. As the latter both have callsigns in the country, they can be traced to a certain site. The ITU (1972) lists for both DFD21 and DFC37 as well as for the famous DFD78 - Deutscher Sportverlag the site Bonames [12]. So it is not surprising that the Bonames site is mentioned in conjunction with number station transmissions. But it stopped transmissions in 1972, so definitely afterwards transmissions of any kind did not originate from Bonames. At the beginning of the 1970s number station activity in Central Europe was at a peak level, and DFC37 as well as DFD21 continued afterwards. Simon Mason dates back their history starting at least at the beginning of the 1970's [13]. As Usingen took over not only the transmitters, but also the services it is likely that also the callsigns were transferred to Usingen. Indeed, listeners in the area report that Usingen definitely transmitted the typical West German number station format with the Two Letters. These transmissions were around there even at the beginning of the 1960s, as Wolfgang Bueschel writes. But not only German number stations were around in the Greater Frankfurt area. As the CIA had one head of its West German arm there [14], the area is well suited to be a relay for E5's transmissions. There are reports that the site between Langen and Walldorf-Moerfelden is used for this, though up to now, no reliable reports confirm this.


Thanks goes out to a lot of people for helping to collect the material for this short article. We thank Michael Bethge of the WWDXC as well as Gerd Klawitter and Karl-Michael Gierich for sharing their part of the collective memory of the radio hobbyists, as well as supplying articles and other material about the sites. The Museum of Post and Telecommunications in Frankfurt helped in research of some material. For the possibility of discussions about the technical material my thank goes to Kai Ludwig and Hansjoerg Biener. And we thank the "old" ENIGMA for the lots of material about transmitter sites not only of number stations it gave over the years of its existence.


AFN American Forces Network
DBP Deutsche Bundespost, West German Post
DENA Deutsche Nachrichtenagentur (news agency of the American zone until 1949) and Deutsche Nachrichten GmbH (affiliate of DPA)
DLF Deutschlandfunk
DPA Deutsche Presseagentur, (West-)German Press Agency
DPD Deutscher Pressedienst, news agency in the British zone until 1949
HR Hessischer Rundfunk, public broadcaster for Hessen
kW Kilowatt
MW Mediumwave
Suedena Sueddeutsche Nachrichtenagentur, news agency in the French zone until 1949
SW Shortwave
WWDXC Worldwide DX Club



1 Hermann, S., Kahle, W., Kniestedt, J.: Der deutsche Rundfunk, R.v.Decker's Verlag, G. Schenck, Heidelberg 1994.
2 Maes, L.: Transmitter Documentation Project TDP-SW97, 1997.
4 Brunswig, H., Archiv für das Post- und Fernmeldewesen 1979, 2, 166-186.
7 Fernmeldeamt Eschborn: Erdfunkstelle Usingen.
9 Klingenfuss, J.: The 1999 Super Frequency List, Klingenfuss Publications, Tuebingen 1999.
11 ITU Alphabetical Lists of Call Signs, 5th edition, March 1972.
12 Mason, S.: Secret Signals - The Euronumbers Mystery, Tiare Publications 1991.
13 Eichner, K., Dobbert, A.: Headquaters Germany, edition ost, Berlin 1997.
14 World Radio TV Handbook, 1950 and 1952.


Voice stations | Morse stations | Other modes
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