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 is only used for broadcasting within ITU region 1. Most longwave stations are in Europe. The rest are in Algeria, Morocco and Turkey.

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]

Contents

[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.

[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
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 progamme. 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 500 kW Only active during the daytime
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
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 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
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 500 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  
Height diagram of the antenna towers and antenna masts of longwave broadcasting stations


[edit] Notes and references

  1. ^ 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.
  2. ^ Ground-wave propagation curves for frequencies between 10 kHz and 30 MHz. ITU-R Recommendation P.368-9
  3. ^ Guide to Broadcasting Stations (17th edition ed.). Butterworth. 1973. pp. 18. ISBN 0 592 00081 8. 
  4. ^ http://de.wikipedia.org/wiki/Langwellenrundfunk
  5. ^ World Radio TV Handbook

[edit] See also

[edit] External links



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