Linjesender
Encyclopedia
A Linjesender was a low power longwave
transmitter
used for broadcasting in Norway
. It consisted of a power line communication
system, which fed the radio programme on a frequency in the longwave broadcasting range into an overhead electric power transmission line.
Because Norway has many mountains, there are large spans of power lines quite high above the ground. In such regions, the power line served as antenna for the Linjesender.
The typical powers used by Linjesenders were between 250 watts and 2 Kw. Most systems used frequencies in the longwave
band or in between the LW and MW band although some used medium wave or frequencies below the standard LW band which required special receivers.
Similar systems were used in Germany
, where it was called "Drahtfunk" and in Switzerland
, where it was called "Telefonrundspruch" and used telephone
lines.
In the 1930s some towns in Great Britain
used wire broadcasting experimentally either over dedicated cables (sometimes as baseband
audio) or on power lines. However as the coverage of conventional broadcast stations improved the popularity of these "radio relay" or "rediffusion" systems waned.
Wired broadcasting had several advantages over conventional broadcasting:
On the other hand there were practical and economic difficulties in extending such services to remote or thinly populated regions. Wired broadcasting could also be used by governments as a tool of censorship
through promoting ownership of wire-only receivers which couldn't receive foreign stations.
The last Linjesender in Norway was shut down in 1987 although the Swiss counterpart survived another ten years.
An example of the programs carried by Telefonrundspruch in Switzerland:
Longwave
In radio, longwave refers to parts of radio spectrum with relatively long wavelengths. The term is a historic one dating from the early 20th century, when the radio spectrum was considered to consist of long, medium and short wavelengths...
transmitter
Transmitter
In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...
used for broadcasting in Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
. It consisted of a power line communication
Power line communication
Power line communication or power line carrier , also known as power line digital subscriber line , mains communication, power line telecom , power line networking , or broadband over power lines are systems for carrying data on a conductor also used for electric power transmission.A wide range...
system, which fed the radio programme on a frequency in the longwave broadcasting range into an overhead electric power transmission line.
Because Norway has many mountains, there are large spans of power lines quite high above the ground. In such regions, the power line served as antenna for the Linjesender.
The typical powers used by Linjesenders were between 250 watts and 2 Kw. Most systems used frequencies in the longwave
Longwave
In radio, longwave refers to parts of radio spectrum with relatively long wavelengths. The term is a historic one dating from the early 20th century, when the radio spectrum was considered to consist of long, medium and short wavelengths...
band or in between the LW and MW band although some used medium wave or frequencies below the standard LW band which required special receivers.
Similar systems were used in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, where it was called "Drahtfunk" and in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, where it was called "Telefonrundspruch" and used telephone
Telephone
The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...
lines.
In the 1930s some towns in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
used wire broadcasting experimentally either over dedicated cables (sometimes as baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...
audio) or on power lines. However as the coverage of conventional broadcast stations improved the popularity of these "radio relay" or "rediffusion" systems waned.
Wired broadcasting had several advantages over conventional broadcasting:
- Less susceptible to interference
- Potentially greater choice of stations (as overcrowding on the frequency bands was less of a problem)
- Potentially greater audio quality as wired transmissions weren't subject to the same restrictions on bandwidth as terrestrial AM broadcasts.
- In a mountainous country like SwitzerlandSwitzerlandSwitzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
it was difficult to obtain satisfactory national coverage with conventional transmitters. Particularly in the 1930s when transmissions were typically less powerful than today.
On the other hand there were practical and economic difficulties in extending such services to remote or thinly populated regions. Wired broadcasting could also be used by governments as a tool of censorship
Censorship
thumb|[[Book burning]] following the [[1973 Chilean coup d'état|1973 coup]] that installed the [[Military government of Chile |Pinochet regime]] in Chile...
through promoting ownership of wire-only receivers which couldn't receive foreign stations.
The last Linjesender in Norway was shut down in 1987 although the Swiss counterpart survived another ten years.
An example of the programs carried by Telefonrundspruch in Switzerland:
- 175 kHz Swiss Radio International
- 208 kHz RSR1 “la première” (French)
- 241 kHz “classical music”
- 274 kHz RSIRSI-Business:*RADARSAT International, a subsidiary of MacDonald Dettwiler and Associates*Red Sector Incorporated, a demo and "warez" group*Resource Software International Ltd., a communication management call accounting software company* Resin Systems Inc....
1 “Rete Uno” (Italian) - 307 kHz DRS 1DRS 1DRS 1 is a Swiss radio channel, one of six operated by SR DRS, with its headquarters in Zürich.Launched in 1931 it was the first German-language radio station for German-speaking Switzerland....
(German) - 340 kHz “easy music”
External links
- http://members.aon.at/wabweb/radio/lw2.htm
- http://www.nrhf.no/nrhf-sendere-AM.html