Longwave

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Longwave can also refer to the economics concept of Kondratiev waves, or to the rock band Longwave

The Longwave radio broadcasting band is the range of frequencies between 148.5 - 283.5 kHz, which correspond to wavelengths longer than 600 meters. This range is included within the low frequency band (but the low frequency band extends above and below longwave signals). 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 interference-caused fadeouts. Instead, the D-layer of the ionosphere and the surface of the earth serve as a waveguide directing the signal.

The earliest radio transmitters were all longwave transmitters, because propagation of radio waves of higher frequency was not yet understood. Radio alternator or spark-gap transmitters were commonly used to generate the radio frequency carrier wave.

[edit] Broadcasting

In Europe, North Africa and Asia, 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) 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

Some stations derive the value of their carrier from an atomic clock. It can be therefore used as frequency standard.

In North America during the 1970's the longwave frequencies 167, 179 and 191KHz were used for a short lived network of Civil defence emergency broadcsting stations with stations at Ault, Colorado and Cambridge, Kansas. Nowadays the 160-190KHz range is used there for Amateur radio.

[edit] Radio navigation

In the Americas, frequencies between 200 and 430 kHz are used for non-directional beacons (NDBs), and do not necessarily follow the same 9 kHz spacing that other areas do.

[edit] List of longwave broadcasting transmitters

List of the most important longwave broadcasting transmitters (Source: http://de.wikipedia.org/wiki/Langwelle).

Frequency	Name of transmitter	Country	Location	Kind of aerial	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	100 kW
162 kHz	France Inter	France	Allouis	two guyed steel lattice masts, height 350 m, fed on the top	2000 kW
171 kHz	Radio Medi	Morocco	Nador	directional aerial consisting of at least two guyed steel lattice masts, 380 metres high	2000 kW
	Radio Rossiya	Russia	Kaliningrad		1200 kW
177 kHz	Deutschlandradio Kultur	Germany	Zehlendorf near Oranienburg	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 in DRM-Mode
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 Program
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	Guyed steel lattice mast	50 kW
	BBC Radio 4	United Kingdom	Westerglen	Guyed steel lattice mast, height 152 m	50 kW
	Polish Radio 1	Poland	Raszyn	Guyed insulated mast, 335 m high	500 kW	only active at daytime
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	Polish Radio 1	Poland	Solec Kujawski	2 guyed radio masts fed on the top, heights 330 m and 289 m	1000 kW	Earlier tranmitter site Konstantynow
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
243 kHz	Danmarks Radio	Denmark	Kalundborg	Alexanderson aerial, carried from 2 118 Meter high freestanding steel lattice towers	300 kW
252 kHz	RTA Algier	Algeria	Tipaza		1500 kW	French programme; during nighttime half transmitter-power
	RTÉ Radio 1	Ireland	Clarkestown	Guyed steel lattice mast, insulated against ground, height 248 m	500 kW	Earlier used by Atlantic 252 and TeamTalk 252, decreases power at night
261 kHz	Transmitter Burg	Germany	Burg	Cage aerial on 324 m high guyed steel lattice mast, 210 m high steel tube mast, insulated against ground, omnidirectional radiation	200 kW	inactive at the moment, formerly used by Radio Wolga and Radioropa Info
	Radio Rossiya	Russia	Taldom		2500 kW	Most powerful transmitter in the world
	Radio Horizont	Bulgaria	Vakarel		60 kW
270 kHz	ČRO 1 - Radiožurnál	Czech Republic	Topolna	two grounded guyed steel lattice mast with cage aerials, height 257 m, directional radiation with maximum of radiation in East-West direction	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
	BR1	Belarus	Minsk		500 kW

Height diagram of the antenna towers and antenna masts of longwave broadcasting stations

[edit] See also

• Very low frequency

• Electromagnetic spectrum: Shortwave, Low frequency, Groundwave, Skywave
  • Radio: AM radio, BBC Radio 4, BBC Light Programme, Radio clock, Office de Radiodiffusion Télévision Française, Warsaw radio mast, Digital Radio Mondiale, International broadcasting,
  • Shipping: Satellite navigation system, Navigation, Shipping Forecast
• Lists: List of wave topics
• Other: 1 E3 m, National Institute of Standards and Technology, Fail-Safe

[edit] External links

• Tomislav Stimac, "Definition of frequency bands (VLF, ELF... etc.)". IK1QFK Home Page (vlf.it).
• 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".
• [1] - LF activity of British radio amateur G3XDV

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