Longwave

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). [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.]

Unlike the medium wave band, which is widely used throughout the world, the longwave band is only used for broadcasting within ITU region 1, i.e. Europe, Africa, the Middle East west of the Persian Gulf including Iraq, the former Soviet Union and Mongolia.

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. [cite book |title = Guide to Broadcasting Stations |publisher = Butterworth |edition = 17th edition |isbn = 0 592 00081 8 |pages = p 18 |year = 1973]

Some stations derive their carrier frequencies from an atomic clock. They can be therefore used as frequency standards.

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.

List of longwave broadcasting transmitters

List of the most important longwave broadcasting transmitters (Source: [http://de.wikipedia.org/wiki/Langwellenrundfunk http://de.wikipedia.org/wiki/Langwellenrundfunk] and World Radio TV Handbook).

Notes and references

ee 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, Groundwave, Skywave, Mediumwave
* Radio broadcasting: 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, WGU-20

External links

* Tomislav Stimac, " [http://www.vlf.it/frequency/bands.html Definition of frequency bands (VLF, ELF... etc.)] ". IK1QFK Home Page.
* [http://www.mwcircle.org The Medium Wave Circle] - The premier club for MW/LW enthusiasts
* [http://www.mwcircle.org/freemag.htm Medium Wave News] - Published regularly since 1954
* [http://www.emwg.info Euro-African Medium Wave Guide]
* " [http://www.lwca.org/ Longwave Club of America] ".
*cite book | author=Klawitter, G. | coauthors=Oexner, M., Herold, K. | title=Langwelle und Längstwelle | isbn=3-89632-043-2 | publisher=Siebel Verlag GmbH |location=Meckenheim | year=2000 | language=German | pages=116-131 | chapter=8.2 Langwellenrundfunk
*Citation
last=Busch
first=Heinrich
year=2001
date=2001-11-14
title=Luftschiff Graf Zeppelin LZ127
url=http://www.seefunknetz.de/lz127.htm (German)