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Kalundborg, Then and Now


Ydun Ritz, of the Medium Wave Info forum, takes us to beautiful Denmark, for a tour of the well-known long wave transmitter site

Ydun Ritz, of the Medium Wave Info forum, takes us to beautiful Denmark, for a tour of the well-known long wave transmitter site at Kalundborg and a closer look at its history, impact and likely future.



I grew up in the countryside, on a farm, where the kitchen was the main room in the farmhouse. It was a cosy place to sit down, especially when my mother had lit the fire in the stove. The big dining table was the place, where we had all our meals and where we children did our homework.

The family's only radio also had its place in the kitchen. It was here, in this warm and friendly place, that my interest in radio began. I studied the dial carefully, with the many names of European cities such as Motala, Vigra, Hilversum, Lahti, Hørby, Allouis and Droitwich. Among them was a Danish city – Kalundborg (Fig. 1).

It was very fascinating listening to foreign languages from home and, after all these years, I still have this thrilling feeling.

The first time I saw the antennas at Kalundborg with my own eyes was around 50 years ago. As a young, newly-trained, radio operator, I signed on to my first job on a ship, which was docking in the port of Kalundborg. Then there were three antenna masts in the area at Gisseløre. Now only two of them are left.

The next time I saw them was not before the 29th August 2017 – on the 90th birthday of the radio station and its famous masts.


Educational Encounters

Following my phone request to see the installation before writing this article, Jens Christian Seeberg, the station manager, kindly invited me to come to Kalundborg on the day of the anniversary and take part in the celebration. There had been some announcements in the local media and quite a few people showed up.

Jens Christian Seeberg has been working at and with the station since 1978. Consequently, he has an enormous store of knowledge about it.

The transmitter is remotely controlled from Høje Taastrup, where Seeberg does his daily work. He and his wife live at Kalundborg, looking after the station on a daily basis, keeping an eye on the pot plants as well as th technical equipment.

I had arranged to attend a lecture on the history of the station, held by Jens Christian (Fig. 2) and a tour of the buildings and the small on-site museum (Fig. 3). The latter is locayed in one of the rooms of the oldest station building.

Arriving at Kalundborg by train I took the footpath along the coast to Gisseløre peninsula. The short walk along the water gave me an excellent view of the two remaining antenna masts. (Fig.4)

Getting close to the station, I was wondering how easy it was to access the area comprising of the radio station and the masts. I should not have worried. There were no fences, no gates, no nothing, except for a well-tended garden! (Fig. 5).

This was not to be compared with radio installations I have visited elsewhere, such as the transmitter sites at Moorside Edge and Holme Moss. In Portugal, I have even seen one of RTP's installations - at Santa Isabel near Coimbra - fenced in and guarded by bullfighting bulls!


Reminiscences and Personal Connections

Back in 1926, there was nothing but fields and some farms on the small peninsula of Gisseløre stretching out in the water south of Kalundborg on the western part of Zealand. It was a wonderful playground for children from the neighbourhood.

And when the construction of the radio station and the antenna masts began, it was followed with great interest by the five year old Hans Meredin Petersen and his playmates. Hans was present on this special day 90 years later and gave a short but lively description of what it was like to watch the construction work in 1927 and what it had been like to see the 1062kHz medium wave antenna mast taken down in June 2012. You can find some background details on this website.

In the early years of the 20th Century, there were several local (low power) radio stations throughout Denmark. For example, Lyngby Radio, north of Copenhagen, which was used for marine traffic too.

There was also Sorø Radio on Zealand as well as the military stations in Ryvangen, Hjørring and Odense. However, they only covered a smaller part of the country.

The Danish opera singer Laurits Melchior (1890 to 1973) was one of the advocates of early radio broadcasting in Denmark. He travelled to London in 1920 to work with Sir Henry Joseph Woods (1869 to 1944) and the Promenade Concerts in Queens Hall. During one of the concerts, Guglielmo Marconi (1874 to 1937) was present. He invited Melchior to witness the first official sound broadcast in the United Kingdom from the Chelmsford radio factory.


Broadcasting in Denmark

When he was back in Denmark, Melchior was eager to start up radio broadcasting. This was easier said than done and it took until 1927 before his mission was accomplished.

When it was finally decided to buy a transmitter, a delegation of four from Statsradiofonien (the Danish State Radio company) went to Germany and United Kingdom to research the market there for transmitters.

They had to choose between a Telefunken from Germany and a Western Electric from the United Kingdom. It was decided to buy the cheapest offer – the 5kW Western Electric model.

However, it turned out, that this was not the cheapest long-term solution after all because spare parts for the transmitter were rather expensive!


The Impact of the Transmitter

The first transmitter kept my grandparents and their contemporaries informed with news, music, radio plays, weather forecasts and more until 1933 when it was time to find a new and more powerful one.

It was decided to buy and install a 60kW transmitter from Dansk Radio A/S. In 1954, it was, once again, time to change the transmitter. The new choice fell on a Marconi Transmitter, with an effective power of 150kW. This was in service until 1980, when the last analogue transmitter was installed.

Having dismissed the idea of a Telefunken transmitter in 1927, it finally arrived in 1980!  A 150kW  (some sources say 300kW) AEG-Telefunken was installed. It remained operational until February 2007. (Fig. 6)

At that time, DR closed down its long wave transmission and the only AM frequency left was the MW 1062kHz, also in Kalundborg.


Reviving Long Wave

Luckily, this was not the end of broadcasting from Kalundborg in AM mode!

In 2008, Turkey had left the frequency 243kHz in Erzurum and the frequency was now empty. For some reason, DR decided to revive its long wave transmissions. As a result, a new, digital 50kW Nautel transmitter was acquired and installed (Fig. 7).

However, from the beginning, this was not in use with public programmes from DR. Instead, the time and facilities were used for test transmissions in DRM. Many DXers across Europe heard the signals and reported what they had heard. Most of the DRM tests went out with an effective power of 0.2kW. However, sometimes the transmitter was powered up and used at its full capacity of 50kW. On 16th June 2011, it was finally activated and went into AM mode (Fig. 8).

DR's programmes were transmitted in parallel on both long and medium wave until 27th June, when the medium wave transmitter fell silent. The new transmitter is much more efficient than the previous analogue ones and runs at a significantly lower power level, which should result in some cost savings.


The Masts

The masts from 1927 were 105m-high steel constructions, built on the shipyard in Nakskov. Each mast had a nine-metre crossbeam and eight top-wires. They were connected with some 160m- long antenna wires.

In 1954, at the same time as the Marconi transmitter was installed, the masts were extended by 15m, reaching a total height of 118m. Menanwhle, the crossbeams were extended to a length of 23m.

With the plans of a revival for long wave and the purchase of the new, digital, Nautel transmitter in 2008, the crossbeams were changed for the third time; this time they were shortened. The new towers now have only two top wires as compared to the previous eight. However, they still work together as a top capacitance loaded ’Alexanderson’ antenna.

Photographs reveal that some of the insulators in the end guy wires have been shorted during calibration. Consequently, the top capacitance wires now extend electrically down to almost ground level.

From 1951 to 2007, the radio station in Kalundborg was also home for DR's MW frequency of 1062kHz at 250kW. The antenna for this frequency was 144m high. In June 2012, the installation was dismantled; now you can hardly see that there ever has been a third antenna mast on Gisseløre.

On 28th October 2013, a severe storm hit Denmark with heavy winds and gusts of more than 50 m/s (180 km/h). Trees fell down, buildings were damaged and the two top wires of the long wave antenna blew to the ground. It took days to undertake the necessary repair and the transmitter was off air until 11th November 2013.


On the Air

Kalundborg 243kHz is on the air for a couple of hours a day. Table 1 shows the schedule, split into four blocks. Each Danish Radio (DR) transmission starts with an announcement in Danish and then the interval signal. This signal is the oldest known Danish song: Jeg drømte mig en drøm I nat.ømte_mig_en_drøm_i_nat


The Future

How long will there still be long wave transmitters? Is there going to be a ’long (wave) good-bye’? How long can we still listen to a noisy but stable signal on long wave?

According to the 2018 edition of the World Radio & TV Handbook (WRTH), only 26 long wave stations are left in the entire world. Among them is the transmitter in Kalundborg.

The Danish parliament has been tasked to negotiate a new Public Service Agreement in 2018, following a proposal from the Ministry of Cultural Affairs. Kalundborg might be a target, even if it is prepared for the future, digital as it is and with low energy costs.

The Answer is Blowin’ in the Wind, but I am optimistic and looking forward to an invitation in 2027, when Kalundborg will be celebrating its 100th birthday!


Editor’s Reading Suggestions: A Brief A-Z of Long Wave (LW) Resources



Carey, K. (2007) Listening to Long Wave (Reynoldsburg, Ohio: Universal Radio Research)

Cawte, M. (1996) Making Radio into a Tool of War:

Definition of Frequency Bands:

European and Asian LW Stations:

European LW and MW History:

History of Radio Luxembourg:

Irish LW:

Jilly’s LW DXing Page:

Long Wave Club of America (LWCA):

LW Broadcast Stations (HF Underground):

LW DXing (NZ DX League):

Medium Wave Circle:

MW List Quick & Easy:

Russian LW:

The Sounds of Longwave (Kevin Carey – Universal Radio, US):

Vintage LW Receivers:

Voices from the Ether – History of Radio:

Wiessala, G.: History and Legacy of Longwave Broadcasting in Europe (The Spectrum Monitor, Vol. 4, No. 5, May 2017: 13-15)

William Hepburn’s Radio and TV DX Information Centre:

Ydun’s Medium Wave Info:



Table 1: Kalundborg 243kHz Schedule:

Block I


05:45 Weather Forecast

06:00 News – in parallel with DR P4


Block II


08:00 News – in parallel with  DR P4

08:03 Morning church service – from the Cathedral of Copenhagen

08:30 Gymnastic

Content continues after advertisements

08:45 Weather forecast

09:00 News – in parallel with DR P4


Block III


11:45 Weather forecast

12:00 News – in parallel with DR P4


Block IV


17:45 Weather forecast

18:00 News – in parallel with DR P4

18:03 Navigational warnings


This article was featured in the July 2018 issue of Radio User