Editing Kalundborg Transmitter

{{redirect|243 AM|{{chem|243|Am}}|Americium-243}}
{{Use dmy dates|date=December 2023}}
{{Infobox building
|name = Kalundborg Transmitter
|image = Kalundborg renewed longwave towers.jpg
|building_type = Mast
|location = [[Kalundborg]], [[Zealand]]
|status = Built
|completion_date = 1927
|destroyed = 
|height = {{convert|147|m|ft|2|abbr=on}}
|coordinates = {{coord|55|40|39|N|11|04|09|E|region:DK_type:landmark|display=inline,title}}
|architect =
|pushpin_map = Denmark
}}
Kalundborg Radio was a major transmission facility for [[longwave|long]]- and [[mediumwave]] at the harbour of [[Kalundborg]] in [[Denmark]]. Longwave broadcasts on 243&nbsp;[[kHz]] began on 27 August 1927 and ceased on 31 December 2023.
Mediumwave broadcasts on 1062&nbsp;kHz began on 1 October 1951 and ceased in June 2011.

== History ==
The transmitter site was inaugurated on 27 August 1927 and started broadcasting [[DR P1|the first channel of Danish radio]] on 243&nbsp;kHz longwave (LW) with 300&nbsp;[[kilowatts|kW]]. On 1 October 1951, mediumwave (MW) broadcasts of [[DR P2]] commenced on 1062&nbsp;kHz (282&nbsp;m wavelength) with 250&nbsp;kW. These two transmitters had a common reserve transmitter.

On 15 February 2007 at 00:05, LW transmissions from Kalundborg were suspended after 80 years of service. They resumed in [[Digital Radio Mondiale]] (DRM) mode at reduced power (200&nbsp;W) on 3 October 2008 after substantial modifications to the aerial earlier that year. 
During 16-31 October 2009, the old MW and LW reserve transmitter served in place of the regular MW and LW DRM transmitters.
Until mid-June 2011, broadcasts on 1062&nbsp;kHz at 250&nbsp;kW continued on a restricted time schedule. After that, the MW transmitter was taken out of service.

A new 50&nbsp;kW LW transmitter replaced the MW service. During 6-12 September 2012, the transmitter also broadcast [[BBC]] programmes with 10&nbsp;kW of power in DRM mode outside [[Danmarks Radio|DR's]] broadcast blocks in connection with the international broadcasting exhibition [[IBC 2012]] in [[Amsterdam]].<ref>{{Cite web|url=https://www.drm.org/drm-kalundborg-transmission/|title=Digital Radio Mondiale &#124; DRM Kalundborg transmission|accessdate=13 December 2023}}</ref>
[[Marine weather forecasting|Shipping Forecast]] bulletins produced by the [[Danish Meteorological Institute]] (''Danmarks Meteorologiske Institut'') ceased on 1 November 2023 ahead of full closure of the longwave service on 31 December 2023.<ref>{{Cite web|url=https://www.youtube.com/watch?v=j7SvL-h7fWM|title=Last broadcast of DR Langbølge 243 kHz (31.12.2023)|accessdate=2 January 2024}}</ref>

It was possible to receive the LW signal of the Kalundborg transmitter outdoors over a distance of 800-1,000&nbsp;km on a standard transistor radio or a longwave-compatible car radio. By connecting the receiver to a stationary or a maritime wire, frame, or active antenna, reception improved up to 1,500&nbsp;km of range.<ref>{{Cite web|url=http://www.drmradio.dk/Radiomodtagelse-da.htm|title=drmRADIO: Forbedret modtagelse|website=www.drmradio.dk|accessdate=13 December 2023}}</ref>

Every year on 4 May, Danmarks Radio rebroadcast the "message of liberation,"<ref>{{Cite web|url=https://www.kb.dk/en/inspiration/liberation/message-liberation|title=Message of Liberation|accessdate=2 January 2024}}</ref> from the Kalundborg transmitter in an hour-long memorial broadcast that began after the news at 20:00. On 4 May 1945, the Danish service of the BBC broadcast the original "message of liberation," marking the end of [[WWII]] in Denmark: "At this moment, it is announced that Montgomery has stated that the German troops in Holland, Northwest Germany, and Denmark have surrendered."

== LW and MW antennas ==
The LW antenna was an [[Ernst Alexanderson|Alexanderson aerial]] with two grounded 118&nbsp;m steel lattice radiating towers connected by top capacitance wires. The northern tower was fed from the transmitter through a top coil, with the top coil of the southern slave tower being fed via the capacitance wires. The MW aerial was an insulated guyed steel lattice mast with a height of 147 metres. All masts virtually stood in the sea on the narrow Gisseløre peninsula, providing excellent radiation efficiency.

== Normal daily programming schedule ==
Times given in [[Central European Time]]. Source:<ref>{{Cite web|url=https://www.dr.dk/tvsepl/DRPROG/|title = Cmwebol25.dr.dk - /Tvsepl/DRPROG/}}</ref><ref>{{cite web | url=http://www.dkradio.dk/lrdab.htm | title=Dkradio.dk - Oversigt over DAB, satellitradio og langbølge }}</ref>
*06.00 - 06.05: News (''Radioavisen''), rebroadcast from [[DR P4]] København
*08.00 - 0.805: News (''Radioavisen''), rebroadcast from [[DR P4]] København (Not broadcast on Sundays and public holidays)
*08.05 - 08.30: [[Holy Mass|Act of worship]] - Morning Devotion (''Morgenandagt'') from the [[Church of Our Lady, Copenhagen|Church of Our Lady in Copenhagen]] produced by [[DR P2]] (Not broadcast on Sundays)
*08.30 - 08.45: Morning gymnastics - Body and Movement (''Krop og bevægelse'') produced by [[DR P5]]
*09.00 - 09.05: News (''Radioavisen''), rebroadcast from [[DR P4]] København
*12.00 - 12.05: News (''Radioavisen''), rebroadcast from [[DR P4]] København
*18.00 - 18.05: News (''Radioavisen''), rebroadcast from [[DR P4]] København

== Photo gallery ==
<gallery>
File:Kalundborg-mediumwave.swn.jpg|The mediumwave antenna
File:Kalundborg-longwave.swn.jpg|The longwave antenna
File:Kalundborg-mediumwave-base.swn.jpg|The base of the mediumwave antenna factory
</gallery>

==See also==
*[[List of towers]]
*[[List of masts]]

==References==
{{Reflist}}

==External links==
* [http://www.drmradio.dk How to receive DRM from Kalundborg]
* {{Structurae|id=20010743|title=Kalundborg Transmission Towers (1927)}}
* {{Structurae|id=20010741|title=Kalundborg Transmission Mast (1951)}}
*[http://www.skyscraperpage.com/diagrams/?b45594 Drawings of Kalundborg Radio Tower 1 - SkyscraperPage.com]
*[http://www.skyscraperpage.com/diagrams/?b45595 Drawings of Kalundborg Radio Tower 2 - SkyscraperPage.com]
*[http://www.skyscraperpage.com/diagrams/?b45596 Drawings of Kalundborg Radio Mast - SkyscraperPage.com]

{{Kalundborg Municipality}}

[[Category:Towers in Denmark]]
[[Category:Mass media in Denmark]]
[[Category:Buildings and structures in Kalundborg Municipality]]
[[Category:Longwave radio stations]]
[[Category:Kalundborg|Transmitter]]