The longwaveradio broadcasting band is the range of frequencies lying between 148.5 and 283.5 kHz (corresponding to wavelengths between 1000 and 2000 metres).
This range is included within the low-frequency (LF) band, although the LF band covers a wider range than that used for longwave transmissions.
Longwave signals have the property of following the curvature of the earth, making them ideal for continuous, continental communications. Unlike shortwave radio, longwave signals do not reflect or refract using the ionosphere, so there are fewer and less severe interference-caused fadeouts. Instead, the D-layer of the ionosphere and the surface of the earth serve as a waveguide directing the signal[citation needed].
Historical significance
Essentially all radio transmitters before 1924 were longwave transmitters[citation needed]. Propagation of shorter wavelengths was not understood until the shortwave experiments by amateur radio operators in 1923 and by Marconi in 1924. Spark-gap transmitters were used prior to World War I, until the development of powerful Radio alternators by General Electric just prior to the war. Vacuum tubes began to be used to generate radio frequencies in the mid-1920s.
After 1924, use of longwave radio for long distance communication began to decline, as much less expensive shortwave transmitters began to carry increasingly heavy volumes of long distance communication. A period of explosive growth of shortwave communications began in 1927, leading to rapid decline in longwave radio usage.
Broadcasting
In Europe, North Africa, Russia and Mongolia (ITU Region 1), longwave radio frequencies in the band 148.5 to 283.5 kHz are used for domestic and international broadcasting. Carrier frequencies are multiples of 9 kHz ranging from 153 to 279 kHz. There are two exceptions in Germany, where two stations are offset by 3 kHz either side of 180 kHz. Historically LW stations operated on frequencies as high as 413 kHz (although the highest carrier frequency currently in use for LW broadcasting is 279 kHz). Some stations derive their carrier frequencies from an atomic clock. It can be therefore used as frequency standard.
Several countries transmitted radio programming over power lines or telephone lines using LW frequencies. These systems were known variously as Linjesender, Telefonrundspruch or Wire Broadcasting however these systems were phased out with the introduction of ISDN and later ADSL and it is believed that there are no longer any in operation[citation needed].
ITU Region 2 note
In the Americas (ITU Region 2), there is no longwave broadcast band. In North America during the 1970s the longwave frequencies 167, 179 and 191 kHz were used for a short-lived network of civil defence emergency broadcasting stations with stations at Ault, Colorado and Cambridge, Kansas[citation needed]. Nowadays the 160-190 kHz range is used there for Part 15 Lowfers amateur and experimental stations. The 190-435 kHz bands is one of the bands used for navigational beacons.
List of longwave broadcasting transmitters
List of the most important longwave broadcasting transmitters (Source: http://de.wikipedia.org/wiki/Langwelle).
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
100 kW
Al Kasirha
Algeria
Bechar
Three guyed steel lattice masts
1000 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
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
150/75 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)
183 kHz
Europe 1
Germany
Felsberg
Directional aerial, 4 insulated guyed steel lattice masts, heights: 282 m, 280 m, 276 m and 270 m, 2 234 metre tall guyed steel lattice masts, which are insulated against ground as backup antenna
2000 kW
French Programme
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
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.
BBC Radio 4
United Kingdom
Burghead
Omnidirectional aerial, guyed steel lattice mast
50 kW
BBC Radio 4
United Kingdom
Westerglen
Omnidirectional aerial, guyed steel lattice mast, height 152 m
50 kW
Polskie Radio Parlament/Program 1
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 220m
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
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
Danmarks Radio
Denmark
Kalundborg
Alexanderson aerial, carried from 2 118 Meter high free-standing steel lattice towers
300 kW
Stop 15 February 2007
252 kHz
RTA Algier
Algeria
Tipaza
Omnidirectional aerial, single guyed lattice steel mast
1500 kW
French programme; during night-time half transmitter-power
RTÉ Radio 1
Ireland
Clarkestown
Omnidirectional aerial, guyed steel lattice mast, insulated against ground, height 248 m
500 kW
Earlier used by Atlantic 252 and TeamTalk 252, decreases power at night to 100kW, one website reported the callsign of this station to be EIRE
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
Musicmann279
Isle of Man
± 5 km off Ramsey
Crossed field antenna
500 kW
Tests originally planned to begin in early 2005 pending a summer 2005 launch; as of 2006, considerable uncertainty as to actual launch date; as of 2007, key personnel have resigned and company's future is uncertain. In October 2007 the Company's web sites disappeared.
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
Radio: AM radio, BBC Radio 4, BBC Light Programme, Radio clock, Office de Radiodiffusion Télévision Française, Warsaw radio mast, Digital Radio Mondiale, International broadcasting,