LowFER (Low-Frequency Experimental Radio) refers to experimental radio communication practiced by hobbyists on

frequencies Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...

below 300 kHz, a part of the

radio spectrum The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particula ...

known as

low frequency Low frequency (LF) is the ITU designation for radio frequencies (RF) in the range of 30–300 kHz. Since its wavelengths range from 10–1 km, respectively, it is also known as the kilometre band or kilometre waves. LF radio waves ...

. The practitioners are known as "''LowFERs''".

Practices

LowFER operation is practiced in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

on radio frequencies between 160 kHz and 190 kHz which is sometimes referred to as the 1750-meter band, and in the past as the 1875-meter band. In much of the world, including the U.S., there is an adjacent

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency radio spectrum, spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emer ...

band at 136–138 kHz with a number of U.S.

amateur radio operator An amateur radio operator is someone who uses equipment at an amateur radio station to engage in two-way personal communications with other amateur operators on radio frequencies assigned to the amateur radio service. Amateur radio operators ...

s authorized to transmit on that band (notification and lack of objection from power utilities is required). Radio operators who conduct low-frequency experimental operations on the LowFER band are known as ''LowFERs'' (pronounced "loafers"). Many LowFERs are also licensed

radio amateurs An amateur radio operator is someone who uses equipment at an amateur radio station to engage in two-way personal communications with other amateur operators on radio frequencies assigned to the amateur radio service. Amateur radio operators ...

, although an amateur radio license is not required for LowFER communications in those countries in Region 2, as long as the power is below a nationally prescribed limit, often 1 W.

Equipment

Practical antennas at these frequencies are much shorter than the wavelength, making it difficult to efficiently radiate much useful power. By current U.S. and Canadian regulations, LowFER transmitters may not have antenna and feed line lengths longer than , or final RF stage input powers that exceeds 1

watt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Work ...

Telegraphy Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pi ...

and digital modes are the most commonly used for communications, but speech transmission via

amplitude modulation Amplitude modulation (AM) is a signal modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the instantaneous amplitude of the wave is varied in proportion t ...

(AM) or

single-sideband modulation In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of signal modulation used to transmit information, such as an audio signal, by radio waves. A refinement of amplitu ...

(SSB) is also allowed. Even with such short antennas and low transmit power, LowFER stations have been heard at distances approaching 1,000 miles by listeners using sophisticated receiving setups.

Similar activities

LF amateur radio allocation

In Europe, and generally in ITU Region 1, the LowFER frequency range (160–190 kHz) is used for broadcasting and is unavailable for two-way communications use. In the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

there was an allocation for radio amateurs at 73 kHz between 1998 and 2002. The

International Telecommunication Union The International Telecommunication Union (ITU)In the other common languages of the ITU: * * is a list of specialized agencies of the United Nations, specialized agency of the United Nations responsible for many matters related to information ...

's 2007 World Radiocommunication Conference (WRC-07) in

Geneva Geneva ( , ; ) ; ; . is the List of cities in Switzerland, second-most populous city in Switzerland and the most populous in French-speaking Romandy. Situated in the southwest of the country, where the Rhône exits Lake Geneva, it is the ca ...

agreed a secondary allocation 135.7–137.8 kHz (the 2200-meter band) to the Amateur Service on 9 November 2007, marking the first time since amateur allocations began that there has been an amateur band below the

medium wave Medium wave (MW) is a part of the medium frequency (MF) radio band used mainly for AM radio broadcasting. The spectrum provides about 120 channels with more limited sound quality than FM stations on the FM broadcast band. During the daytim ...

broadcast band. Transmitter power is limited to one watt ERP (meaning an inefficient antenna can be fed a higher power).

MedFER

In the U.S., license-free operation is also allowed on the medium frequency band, also known as the AM broadcast band. Similar to LowFER, MedFER is medium-frequency experimental radio. MedFER enthusiasts operate under FCC Part 15 rules 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 AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transmi ...

band.

HiFER

HiFER is high-frequency experimental radio operating within a 14 kHz-wide band centered at 13.56 MHz. This frequency range is allocated to industrial, scientific and medical uses as well as low-power communication devices under FCC Part 15 rules, where a small level of radio frequency radiation is allowed without licensing. (See

RFID Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, a radio receiver, and a transmitter. When tri ...

for other uses of this frequency.)

References

{{reflist

External links

Longwave Club of America

Medfer site
Amateur radio Radio hobbies