LowFER

LowFER

LowFER (Low-Frequency Experimental Radio) is a license-free form of two-way radio communications practiced on frequencies below 500 kHz.

Practices

LowFER operation is practiced in the United States and Canada on radio frequencies between 160 kHz and 190 kHz. In the US, license-free operation is also allowed on the medium frequency band, also known as the AM Broadcast Band. Proposals have also been made for Amateur radio operations at 136 kHz with a number of U.S. Hams holding experimental licenses authorized to conduct tests on that frequency. In Europe, the LowFER band is used for broadcasting and is unavailable for two-way communications use. In England there was an allocation for radio amateurs at 73kHz from 1998 to 2002. The International Telecommunication Union's 2007 World Radiocommunication Conference (WRC-07) in Geneva agreed a secondary allocation 135.7-137.8 kHz to the Amateur Service on Friday November 9, marking the first time since amateur allocations began that there has been an amateur band below the Medium Wave broadcast band.

US and Canadian radio operators who conduct low-frequency experimental operations on the LowFER band are known as "LowFERs". Many LowFERs are also licensed radio amateurs, although an amateur radio license is not required for LowFER communications in those countries. [http://www.arrl.org/news/features/2001/08/04/1/ ARRL] ]

Equipment

Antenna efficiencies at these frequencies make it difficult to radiate much useful power. By current US and Canadian regulations, LowFER transmitters may not use antennas longer than fifty feet or final RF stage input powers that exceeds one watt. In the United Kingdom (which only has LowFER allocations for licensed amateurs), the limit is 1 Watt erp, meaning an inefficient antenna can be fed a higher power. Telegraphy and digital modes are the most commonly used for communications, but speech transmission via amplitude modulation (AM) or single-sideband modulation (SSB) is also allowed. Even with such short antennas and low transmit power, lowFER stations have been copied at distances approaching 1000 miles by listeners using sophisticated receiving setups. [ [http://www.arrl.org/news/features/2001/08/04/1/ ARRL] ]

MedFER

Similar to LowFER, MedFER is medium-frequency experimental radio. MedFER enthusiasts operate using 0.1 W (a tenth of a watt) and a three-meter-long antenna between 510 kHz and 1705 kHz, coinciding with the U.S. AM radio band. [ [http://www.arrl.org/news/features/2001/08/04/1/ ARRL] ]

HiFER

HiFER is high frequency experimental radio operating within a 14kHz-wide band centered at 13.56MHz. [ [http://www.lwca.org/sitepage/part15/index-what.htm Longwave Club OF America] ] (See RFID for other uses of this frequency).

References

External links

* [http://www.lwca.org/ Longwave Club of America]
* [http://www.altair.org/lowfer.html Altairs LOWFER page]
* [http://www.ussc.com/~turner/psk_medfer.html Medfer site]


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Lowfer — (Low Frequency Experimental Radio) ist die Bezeichnung einer speziellen Form des Amateurfunks, wenn Funkbetrieb auf dem sehr langwelligen 2,2 Kilometer Band stattfindet. Der Frequenzbereich 135,7 bis 137,8 kHz steht als Amateurband für den… …   Deutsch Wikipedia

  • Low frequency — or LF refers to Radio Frequencies (RF) in the range of 30 kHz ndash;300 kHz. In Europe, and parts of Northern Africa and of Asia, part of the LF spectrum is used for AM broadcast service. In the western hemisphere, its main use is for aircraft… …   Wikipedia

  • 136 kHz — The 136 kHz band is the lowest frequency band in which amateur radio operators are allowed to transmit. It is only available for use in some countries but there is a proposal at the WRC 07 World Radiocommunication Conference to make it a world… …   Wikipedia

  • 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… …   Wikipedia

  • Public Emergency Radio of the United States — The Public Emergency Radio of the United States was a communications system conceived during the cold war era in the 1970s for use in case of a national emergency. The system included radio stations and a transmission network, to be activated… …   Wikipedia

  • Langwelle — Als Langwelle (abgekürzt LW) bezeichnet man elektromagnetische Wellen mit Wellenlängen zwischen 1.000 und 10.000 Meter, entsprechend Frequenzen zwischen 30 und 300 kHz (zum Vergleich: Mittelwelle 100 m bis 1000 m; Kurzwelle 10 m bis 100 m;… …   Deutsch Wikipedia

  • Langwellenrundfunk — Der Begriff Langwellenrundfunk bezeichnet den Rundfunk im Langwellenband. Hierfür ist der Frequenzbereich zwischen 148,5 kHz und 283,5 kHz vorgesehen. Er dient heute überwiegend zur terrestrischen Ausstrahlung von nationalen Hörfunkprogrammen… …   Deutsch Wikipedia

  • Baja frecuencia — (LF) Ciclos por segundo: 30 kHz a 300 kHz Longitud de onda: 10 km a 1 km Baja frecuencia o LF (del inglés, iniciales de Low Frequency) se refiere a la banda del espectro electromagnético, y más particularmente a la banda de… …   Wikipedia Español

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”