Longwave
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The longwave radio band is a range of frequencies used for AM broadcasting, which extends from 148.5 to 283.5 kHz. It falls within the low-frequency (LF) part of the radio spectrum (30–300 kHz).[1]
Unlike the medium wave band, which is widely used throughout the world, the longwave band has been primarily used for broadcasting the station identity of Nondirectional Beacons (NDBs) in Morse Code for use by radio direction finders in marine navigation. In voice transmissions, longwave is used only within ITU region 1. Most of the longwave broadcasters are in Europe, the Former Soviet Union and Mongolia. The rest are located in Algeria, Morocco, Western Sahara, and Libya. Saudi Arabia, Egypt, Qatar and the United Arab Emirates have vacant low powered broadcasting allocations. Long wave signals travel particularity well over the Ocean. 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.[2]
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[edit] Time Signals
There are stations between 40 KHz and 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.
- HBG in Prangins, Switzerland on 75 KHz.
- JJY in Japan on 40 KHz and 60 KHz.
There are quite a few clock radios with longwave receivers built in them to calibrate the clocks. They use longwave, rather than shortwave or mediumwave, because the accuracy of the clocks is not affected by the time signal's travel from the transmitter to the ionosphere and to the receiver; as longwave travels by groundwave, rather than skywave.
[edit] Military Communication
The United Kingdom, Russian Federation, United States, Germany, and Sweden use wavelengths below 50 KHz to communicate with their submarines.
Also, nuclear submarines of the Royal Navy are allegedly required to check the signal of BBC Radio 4 on 198 KHz longwave while in British territorial waters. There is a rumor that if there is an unexpected halt in transmission as an indication of an attack on the United Kingdom, they are then required to follow the sealed orders from the Prime Minister.
[edit] Carrier frequencies
Carrier frequencies are exact multiples of 9 kHz ranging from 153 to 279 kHz, except for two stations in Germany on 177 kHz and 183 kHz.
Until the 1970s, some longwave stations in the Soviet Union operated on frequencies as high as 400 kHz, and there was even a station on 433 kHz in Finland.[3]
Some stations, for instance Droitwich in the UK, derive their carrier frequencies from an atomic clock. They can be therefore used as frequency standards; and a radio-control system for Economy 7 storage heaters.
[edit] ITU regions 2 and 3
Outside region 1, there is no longwave broadcasting.
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.
[edit] List of longwave broadcasting transmitters
List of the most important longwave broadcasting transmitters [4][5]
| Frequency | Station name | Country | Location | Aerial type | Power | Remarks |
|---|---|---|---|---|---|---|
| 153 kHz | Deutschlandfunk |  Germany |
Donebach | Directional aerial, two guyed steel lattice masts, 363 m high, fed at the top | 500 kW | Night: 250 kW |
| Antena Satelor / Radio Romania |  Romania |
Braşov | T-aerial on 2 guyed steel lattice masts with a height of 250 metres | 1200 kW | ||
| NRK Finnmark |  Norway |
Ingoy | Omnidirectional aerial, guyed steel lattice mast of 362 m height, fed at the top, ex-Omega equipment | 100 kW | ||
| Chaine 1 |  Algeria |
Kenadsa / Bechar | Three guyed steel lattice masts, height 357 m. | 2000 kW | ||
| 162 kHz | France Inter |  France |
Allouis | Two guyed steel lattice masts, height 350 m, fed on the top | 2000 kW | Time signal phase-modulated |
| TRT |  Turkey |
Agri | 1000 kW | |||
| 171 kHz | Medi 1 |  Morocco |
Nador | Directional aerial consisting of three guyed steel lattice masts, 380 metres tall | 2000 kW | |
| Radio Rossii |  Russia |
Bolshakovo near Kaliningrad | 600 kW | |||
| Radio Rossii |  Ukraine |
Krasne near Lwow | 150/75 kW | inactive at present | ||
| 177 kHz | Deutschlandradio Kultur | Germany |
Zehlendorf near Oranienburg | Omnidirectional aerial, cage aerial mounted on 359.7 m high guyed mast, triangle aerial on 3 150 m high guyed steel lattice masts | 500 kW | Since August 29th, 2005 between 2 and 5 a.m. CET DRM-Mode
Non-standard frequency (not divisible by 9) |
| 180 kHz | TRT | Turkey |
Polatli | 1200 kW | Turkish Programme | |
| 183 kHz DRM Test after 00:00 UTC | 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 kW | French programme. The most powerful longwave transmitter in Germany.
Non-standard frequency (not divisible by 9). |
| 189 kHz | RÚV |  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 kW | RÚV national programs 1 and 2 Rás 1 and Rás 2 |
| RAI |  Italy |
Caltanissetta | Omnidirectional aerial, guyed steel lattice mast, height 282 m | 10 kW | Inactive since August 2004 | |
| 198 kHz | 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 kW | Relays BBC World Service after the end of its own programmes. |
| Burghead (SFN) | Omnidirectional aerial, guyed steel lattice mast | 50 kW | ||||
| Westerglen (SFN) | Omnidirectional aerial, guyed steel lattice mast, height 152 m | 50 kW | ||||
| Chaine 1 | Algeria |
Berkaoui / Ouargla | Three guyed steel lattice masts. | 2000 kW | ||
| Polskie Radio Parlament/Radio Polonia |  Poland |
Raszyn | Omnidirectional aerial, guyed steel lattice mast insulated against ground, 335 m high | 200 kW | excluded for financial reasons the Polish Radio | |
| Radio Majak | Russia |
Sankt Petersburg - Olgino | Omnidirectional aerial, 205 m high guyed steel lattice mast | 150 kW | ||
| 207 kHz | RÚV | Iceland |
Eiðar near Egilsstaðir | Omnidirectional aerial, steel lattice mast insulated against ground, height 220 m | 100 kW | RÚV national programs 1 and 2 Rás 1 and Rás 2 |
| Deutschlandfunk | Germany |
Aholming | Directional aerial, two guyed steel lattice masts, 265 m high, fed at the top | 500 kW | Night: 250 kW | |
| RNE Todo Noticias |  Spain |
Logroño | Directional antenna, 300 metres tall. | >100 kW | ||
| Ukrainian Radio | Ukraine |
Brovary | two guyed steel lattice masts insulated against ground, 259.6 m high, each equipped with a cage antenna at its lower part | 600 kW | ||
| 216 kHz | 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 | 1200 kW | Transmitter site exterritorial, exclave of Monaco |
| 225 kHz | Polskie Radio Program 1 | Poland |
Solec Kujawski | Directional aerial, 2 guyed radio masts fed on the top, heights 330 m and 289 m | 1000 kW | Earlier transmitter site Konstantynów |
| 234 kHz | RTL |  Luxembourg |
Beidweiler | Directional aerial, 3 guyed grounded steel lattice masts, 290 m high, with vertical cage aerials | 2000 kW | Spare transmitter site Junglinster |
| Radio 1 | Russia |
Krasny Bor transmitter | Omnidirectional aerial, 271.5 metres tall guyed mast with cage antenna | 1200 kW | May be inactive at present | |
| 243 kHz (DRM) | DR Kalundborg |  Denmark |
Kalundborg | Semi-directional Alexanderson aerial 153/333 degrees, two grounded 118 m steel lattice radiating towers with interconnecting top wire capacitance | 300 kW | AM suspended 2007, reduced-power DRM from October 2008 |
| 252 kHz | Chaine 1 | Algeria |
Tipaza | Omnidirectional aerial, single guyed lattice steel mast, height 355 m | 1500 kW | French programme; during night-time half transmitter-power |
| RTÉ Radio 1 |  Ireland |
Clarkstown | Omnidirectional aerial, guyed steel lattice mast, insulated against ground, height 248 m | 500 kW | Used for Atlantic 252, 1989–2002. Now the only AM transmitter for RTÉ Radio 1. Decreases power at night to 100kW. | |
| 261 kHz | Transmitter Burg | Germany |
Burg | Omnidirectional aerial, cage aerial on 324 m high guyed, grounded steel lattice mast, 210 m high steel tube mast, insulated against ground | 200 kW | Inactive at the moment, formerly used by Radio Wolga and Radioropa Info |
| Radio Rossii | Russia |
Taldom | Omnidirectional aerial, central mast, 275 metre tall, surrounded by 5 guyed masts on a circle around | 2500 kW | Most powerful transmitter in the world. Currently not used on its maximum power. | |
| Radio Horizont |  Bulgaria |
Vakarel | One of the few Blaw-Knox Towers in Europe, 215m high | 75 kW | ||
| 270 kHz | ČRO 1 - Radiožurnál |  Czech Republic |
Topolna | Directional aerial (maximum of radiation in East-West direction), two grounded 257 m high guyed steel lattice mast with cage aerials | 650 kW | |
| 279 kHz | Belaruskaje Radyjo 1 (BR1) |  Belarus |
Sasnovy | 500 kW | ||
| Radio Mayak (RUS) | Russia |
Yekaterinburg | Omnidirectional aerial, guyed steel lattice mast of 256 m height, fed at the top | 150 kW |
[edit] Notes and references
- ^ Historically, the whole radio spectrum was considered to consist of long, medium and short ‘wavelengths’. Nowadays it is customary to divide the radio spectrum into frequency bands with a 10:1 ratio between each band's upper and lower limits. Terms such as long wave and medium wave are historic and usually refer to bands allocated specifically for broadcasting.
- ^ 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. pp. 18. ISBN 0 592 00081 8.
- ^ http://de.wikipedia.org/wiki/Langwellenrundfunk
- ^ World Radio TV Handbook
[edit] See also
- 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: List of wave topics
- Other: 1 kilometre, National Institute of Standards and Technology, Fail-safe, WGU-20
[edit] External links
- 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
- Klawitter, G.; Oexner, M., Herold, K. (2000). "8.2 Langwellenrundfunk" (in German). Langwelle und Längstwelle. Meckenheim: Siebel Verlag GmbH. pp. 116–131. ISBN 3-89632-043-2.
- Busch, Heinrich (2001-11-14), Luftschiff Graf Zeppelin LZ127, http://www.seefunknetz.de/lz127.htm (German)
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