LowFER
From Wikipedia, the free encyclopedia
LowFER (Low-Frequency Experimental Radio) is a license-free form of two-way radio communications practiced on frequencies below 500 kHz.
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[edit] 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.[1]
[edit] 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.[2]
[edit] 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.[3]
[edit] HiFER
HiFER is high frequency experimental radio operating within a 14kHz-wide band centered at 13.56MHz.[4] (See RFID for other uses of this frequency).
