Longwave
In radio, longwave refers to parts of the radio spectrum with relatively long wavelengths – typically kilometer-sized or greater. The term is a historic one dating from the early 20th century, when the radio spectrum was considered to consist of long, medium and short wavelengths. Most modern radio systems and devices use wavelengths which would then have been considered 'ultra-short'.
In contemporary usage, the term longwave is not defined precisely and its meaning varies across the world. The most common definition is the radio band with wavelengths greater than 1000 meters (frequencies less than 300 kHz),[1][2][3] which would include the ITUs low frequency (LF) (30–300 kHz) and very low frequency (VLF) (3–30 kHz) bands, but sometimes part of the medium frequency (MF) band (300–3000 kHz) is included.[4] In all cases it includes the entire LF band.
In Europe, Africa and large parts of Asia (ITU Region 1), where a range of frequencies between 148.5 and 283.5 kHz is used for AM broadcasting (in addition to the medium wave band), the term longwave usually refers specifically to this broadcasting band.
The Region 1 longwave broadcast band falls wholly within the low frequency band of the radio spectrum (30–300 kHz). Broader definitions of longwave may extend below and/or above it. In the US, the Longwave Club of America is interested in "frequencies below the AM broadcast band",[5] i.e., all frequencies below 535 kHz. (Lower frequencies correspond to longer wavelengths.)
Contents
Non-broadcast use[edit]
Non-directional beacons[edit]
Non-directional beacons transmit continuously for the benefit of radio direction finders in marine and aeronautical navigation. They identify themselves by a callsign in Morse Code. They can occupy any frequency in the range 190–1750 kHz. In North America they occupy 190–535 kHz. In ITU Region 1 the lower limit is 280 kHz.
Time signals[edit]
There are stations in the range 40–80 kHz that transmit time signals to radio clocks. For example:
- WWVB in Colorado on 60 kHz.
- DCF77 in Frankfurt am Main, Germany on 77.5 kHz.
- JJY in Japan on 40 & 60 kHz.
- 66.6 kHz in Taldom transmitter, Russia.
- 50 kHz in Irkutsk, Russia.
- MSF time and 60 kHz frequency standard transmitted from Anthorn in the UK
Radio controlled clocks receive their time calibrations signal with built-in longwave receivers. They use longwave, rather than shortwave or mediumwave, because the accuracy of the clocks is not affected by changes in the time signal's travel from the transmitter to the ionosphere and to the receiver; as longwave travels by groundwave, rather than skywave, the propagation time does not vary.
Military communication[edit]
The United Kingdom, Russian Federation, United States, Germany, and Sweden use frequencies below 50 kHz to communicate with their submarines.
LowFER[edit]
In North America during the 1970s the frequencies 167, 179 and 191 kHz were assigned to the short-lived Public Emergency Radio of the United States. Nowadays the 160–190 kHz range is used in the United States for Part 15 LowFER amateur and experimental stations, and the 190–435 kHz band is used for navigational beacons.
Broadcasting[edit]
Longwave is used for broadcasting only within ITU Region 1. The longwave broadcasters are located in west, north, central and southeast Europe, the former Soviet Union, Mongolia, Algeria and Morocco.
Typically, a larger area can be covered by a longwave broadcast transmitter than a medium-wave one. This is because ground-wave propagation suffers less attenuation due to limited ground conductivity at lower frequencies.[6]
Carrier frequencies[edit]
Carrier frequencies are exact multiples of 9 kHz ranging from 153 to 279 kHz, except for a station in Germany and five Mongolian transmitters.
Until the 1970s, some longwave stations in northern and eastern Europe and the Soviet Union operated on frequencies as high as 433 kHz.[7]
Some stations, for instance Droitwich in the UK, derive their carrier frequencies from an atomic clock. They can be therefore used as frequency standards. Droitwich also broadcasts a low bit-rate data channel, using narrow-shift phase-shift keying of the carrier, for Radio Teleswitch Services.
In January 2014 Russia closed all of its LW transmitters except for one in Caucasus.[8]
List of longwave broadcasting transmitters[edit]
List of stations currently operating:
| Freq. kHz | Station name | Country | Location | Aerial type | Power kW | Coordinates | Remarks |
|---|---|---|---|---|---|---|---|
| 153 | Radio Antena Satelor |  Romania |
Brașov | T-aerial on 2 guyed steel lattice masts with a height of 250 metres. | 200 | 45°45′22.27″N 25°36′26.77″E / 45.7561861°N 25.6074361°E ; 45°45′13.16″N 25°36′25.15″E / 45.7536556°N 25.6069861°E | |
| Chaîne 1 |  Algeria |
Kenadsa | 2000 | ||||
| NRK P1/NRK P2 |  Norway |
Ingøy | Omnidirectional aerial, guyed steel lattice mast of 362 m height, fed at the top, ex-Omega equipment. | 100 | 71°4′17″N 24°5′14″E / 71.07139°N 24.08722°E | The transmitter is important for the fishing fleet in the Barents Sea. | |
| 162 | France Inter |  France |
Allouis | Two guyed lattice steel masts, height 350 m, fed on the top. | 1000/2000 | 47°10′10.45″N 2°12′16.75″E / 47.1695694°N 2.2046528°E ; 47°10′25.34″N 2°12′16.81″E / 47.1737056°N 2.2046694°E | Time signal phase-modulated. |
| 164 | Mongoliin Radio 1 |  Mongolia |
Ulan Bator (Khonkhor) | Cable-stayed steel truss mast.[13] | 500 | 47°47′54.67″N 107°11′14.7″E / 47.7985194°N 107.187417°E | Broadcasts from 15:00 to 22:00 UTC. |
| 171 | Médi 1 |  Morocco |
Nador | Directional aerial consisting of three guyed steel lattice masts, 380 metres tall. | 1600 | 35°02′50.65″N 2°55′22.81″W / 35.0474028°N 2.9230028°W; 35°02′30.27″N 2°55′16.16″W / 35.0417417°N 2.9211556°W ; 35°02′9.89″N 2°55′9.52″W / 35.0360806°N 2.9193111°W | |
| 183 | Europe 1 |  Germany |
Felsberg-Berus | Directional aerial, four ground insulated steel lattice masts. Heights of 270 m, 276 m, 280 m and 282 m. Spare aerial: two ground insulated steel lattice masts of 234 m height. | 2000 | Main antenna: 49°17′4.2″N 6°40′57.73″E / 49.284500°N 6.6827028°E ; 49°16′55.86″N 6°40′46.16″E / 49.2821833°N 6.6794889°E ; 49°16′47.55″N 6°40′34.48″E / 49.2798750°N 6.6762444°E ; 49°16′39.18″N 6°40′22.72″E / 49.2775500°N 6.6729778°E, Spare antenna: 49°17′8.93″N 6°39′31.71″E / 49.2858139°N 6.6588083°E ; 49°17′1.54″N 6°39′23.6″E / 49.2837611°N 6.656556°E | French language channel. The most powerful longwave transmitter in Germany; DRM test after 00:00 UTC. |
| 189 | RÚV Rás 1/RÚV Rás 2 |  Iceland |
Gufuskalar near Hellissandur | Slight oval bi-directivity aerial, top loaded parallel connected triangular loops, mast as a common member, all guys insulated except two radiating diametrically opposed grounded top guys, loops closed by copper straps in the ground from two conducting guy grounding points to base of the guyed steel lattice mast insulated against ground, height 412m. | 300 | 64°54′26″N 23°55′19.5″W / 64.90722°N 23.922083°W | |
| 198 | BBC Radio 4 |  United Kingdom |
Droitwich (SFN) | T-aerial on 2 guyed steel lattice masts insulated against ground with a height of 213 metres. | 500 | 52°17′46.9″N 2°6′24.32″W / 52.296361°N 2.1067556°W ; 52°17′40.4″N 2°6′20.62″W / 52.294556°N 2.1057278°W | All three transmitters carry Radio teleswitch PSK data. Droitwich relays BBC World Service from 01:00 to 05:20 UTC. |
| Burghead (SFN) | Omnidirectional aerial, guyed steel lattice mast, height 154 m. | 50 | 57°41′57.9″N 3°28′4.78″W / 57.699417°N 3.4679944°W | ||||
| Westerglen (SFN) | Omnidirectional aerial, guyed steel lattice mast, height 152 m. | 55°58′33″N 3°48′58.8″W / 55.97583°N 3.816333°W | |||||
| 207 | RÚV Rás 1/RÚV Rás 2 | Iceland |
Eiðar near Egilsstaðir | Omnidirectional aerial, steel lattice mast insulated against ground, height 221 m. | 100 | 65°22′22.93″N 14°20′27.29″E / 65.3730361°N 14.3409139°E | |
| RTM A | Morocco |
Azilal Demnate | 400 | ||||
| 209 | Mongoliin Radio 1 | Mongolia |
Choibalsan | Cable-stayed steel truss mast. | 75 | 48°01′21.02″N 114°33′3.73″E / 48.0225056°N 114.5510361°E | |
| Dalanzadgad | 43°31′54.38″N 104°24′4.16″E / 43.5317722°N 104.4011556°E | ||||||
| Olgii | Omnidirectional antenna, 352.5 metres high guyed mast | 30 | 48°57′24.52″N 89°58′13.15″E / 48.9568111°N 89.9703194°E | ||||
| 216 | Radio Monte Carlo |  Monaco |
Roumoules | Directional aerial, 3 300 metre high guyed steel lattice masts, 330 metre high guyed steel lattice mast as backup aerial. | 700/1400 | 43°47′41.45″N 6°8′48.41″E / 43.7948472°N 6.1467806°E ; 43°47′34.56″N 6°8′59.09″E / 43.7929333°N 6.1497472°E; 43°47′27.7″N 6°9′9.85″E / 43.791028°N 6.1527361°E, Backup antenna: 43°47′36.29″N 6°9′30.61″E / 43.7934139°N 6.1585028°E | Transmitter located in France. In operation from 5:30 to 23:00 CET. |
| 225 | Polskie Radio 1 |  Poland |
Solec Kujawski | Directional aerial, 2 guyed radio masts fed on the top, heights 330 m and 289 m. | 1000 | 53°1′21.01″N 18°15′32.63″E / 53.0225028°N 18.2590639°E 53°1′12.83″N 18°15′44.06″E / 53.0202306°N 18.2622389°E | Earlier Konstantynów was used ( 52°22′3.91″N 19°48′7.04″E / 52.3677528°N 19.8019556°E ) |
| 227 | Mongoliin Radio 1 | Mongolia |
Altai | Cable-stayed steel truss mast. | 75 | 46°19′25.52″N 96°15′31.2″E / 46.3237556°N 96.258667°E | |
| 234 | RTL |  Luxembourg |
Beidweiler | Directional aerial, 3 guyed grounded steel lattice masts, 290 m high, with vertical cage aerials. | 1500/2000 | 49°43′42.57″N 6°19′4.29″E / 49.7284917°N 6.3178583°E ; 49°43′49.2″N 6°19′15.02″E / 49.730333°N 6.3208389°E ; 49°43′55.81″N 6°19′25.67″E / 49.7321694°N 6.3237972°E | Spare transmitter site Junglinster ( 49°43′0.35″N 6°15′28.9″E / 49.7167639°N 6.258028°E ; 49°43′6.56″N 6°15′40.27″E / 49.7184889°N 6.2611861°E ; 49°43′12.75″N 6°15′51.44″E / 49.7202083°N 6.2642889°E ) |
| 243 | DR Langbølge |  Denmark |
Kalundborg | Semi-directional Alexanderson antenna 153/333 degrees, two grounded 118 m steel lattice radiating towers with interconnecting top wire capacitance. | 50 | 55°40′39.27″N 11°4′8.6″E / 55.6775750°N 11.069056°E ; 55°40′32.91″N 11°4′14.33″E / 55.6758083°N 11.0706472°E | Transmitting in time slots only; DRM test from 3 October 2008. |
| 252 | Chaîne 3 | Algeria |
Tipaza | Omnidirectional aerial, single guyed lattice steel mast, height 355 m. | 750/1500 | 36°33′58.14″N 2°28′50.3″E / 36.5661500°N 2.480639°E | French language channel; during night-time half transmitter power. |
| RTÉ Radio 1 |  Ireland |
Clarkstown | Omnidirectional aerial, guyed steel lattice mast, insulated against ground, height 248 m. | 100/300 | 53°27′46″N 6°40′39″W / 53.46278°N 6.67750°W | The only AM transmitter for RTÉ Radio 1. Power is decreased at night to 100 kW. Transmitter will cease broadcasting in 2017.[14] | |
| 270 | ČRo 1 Radiožurnál |  Czech Republic |
Topolná | Directional aerial (maximum of radiation in East-West direction), two grounded 257 m high guyed steel lattice mast with cage aerials. | 50 | 49°7′32.88″N 17°30′45.97″E / 49.1258000°N 17.5127694°E ; 49°7′18.85″N 17°30′41.78″E / 49.1219028°N 17.5116056°E | Broadcast from Monday to Friday 5:00-24:00 CET and 6:00-24:00 CET at weekends. |
| 279 | Belaruskaje Radyjo 1/Radio Stalitsa |  Belarus |
Sasnovy | 500 | 53°24′31″N 28°31′57″E / 53.40861°N 28.53250°E | ||
| Turkmen Radio 1 Watan |  Turkmenistan |
Ashgabat (Kartamak) | Cable-stayed steel truss mast | 150 | 37°51′14.89″N 58°21′57.99″E / 37.8541361°N 58.3661083°E |
List of stations that have closed or are otherwise inactive:
Notes and references[edit]
- ^ "long wave". Cambridge Online Dictionary. Cambridge Univ. Press, UK. 2011. Retrieved December 29, 2012.
- ^ "long wave". MacMillan Online Dictionary. MacMillan Publishers. 2009. Retrieved December 29, 2012.
- ^ Graf, Rudolf F. Graf (1999). Modern Dictionary of Electronics, 7th Ed. US: Newnes. p. 437. ISBN 0750698667.
- ^ The World Book Dictionary. US: World Book, Inc. 2003. p. 1232. ISBN 0716602997.
- ^ "About LWCA". Longwave Club of America. Retrieved 2010-01-05.
- ^ Ground-wave propagation curves for frequencies between 10 kHz and 30 MHz. ITU-R Recommendation P.368-9
- ^ Guide to Broadcasting Stations (17th ed.). Butterworth. 1973. p. 18. ISBN 0-592-00081-8.
- ^ http://www.bbc.co.uk/news/blogs-news-from-elsewhere-25683656
- ^ http://de.wikipedia.org/wiki/Langwellenrundfunk
- ^ World Radio TV Handbook
- ^ [1]
- ^ [2]
- ^ http://structurae.net/structures/ulan-bator-longwave-transmission-mast
- ^ http://www.irishpost.co.uk/news/rte-radio-postpones-longwave-radio-closure-until-2017
- ^ http://www.wiadomosci24.pl/artykul/bez_radia_w_raszynie_105054.html
See also[edit]
- Low frequency: for other uses (military, commercial and amateur) of this part of the radio spectrum (30–300 kHz)
- Electromagnetic spectrum: Very low frequency, Shortwave, Ground wave, Skywave, Medium wave
- Radio broadcasting: AM broadcasting, BBC Radio 4, BBC Light Programme, Radio clock, Office de Radiodiffusion-Télévision Française, Warsaw radio mast, Digital Radio Mondiale, International broadcasting,
- Shipping: Global navigation satellite system, Navigation, Shipping Forecast
- Lists: Index of wave articles
- Other: 1 kilometre, National Institute of Standards and Technology, Fail-safe, WGU-20
External links[edit]
- Tomislav Stimac, "Definition of frequency bands (VLF, ELF... etc.)". IK1QFK Home Page.
- The Medium Wave Circle - The premier club for MW/LW enthusiasts
- Medium Wave News - Published regularly since 1954
- Euro-African Medium Wave Guide
- Longwave Club of America
- How to receive DRM from Kalundborg longwave station
- Reception of long wave and very long wave with ferrite antennas 5-50 kHz
- Klawitter, G.; Oexner, M.; Herold, K. (2000). "8.2 Langwellenrundfunk". Langwelle und Längstwelle (in German). Meckenheim: Siebel Verlag GmbH. pp. 116–131. ISBN 3-89632-043-2.
- Busch, Heinrich (2001-11-14). "Luftschiff Graf Zeppelin LZ127". (German)
- European and Asian Longwave Stations - Medium Wave Radio
- List of long- and mediumwave transmitters with GoogleMap-Links to transmission sites
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