Radioteletype (RTTY) is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations connected by radio rather than a wired link. These machines were superseded by personal computers (PCs) running software to emulate teleprinters. Radioteletype evolved from earlier landline teleprinter operations that began in the mid-1800s. The US Navy Department successfully tested printing telegraphy between an airplane and ground radio station in 1922. Later that year, the Radio Corporation of America successfully tested printing telegraphy via their Chatham, Massachusetts, radio station to the R.M.S. Majestic. Commercial RTTY systems were in active service between San Francisco and Honolulu as early as April 1932 and between San Francisco and New York City by 1934. The US military used radioteletype in the 1930s and expanded this usage during World War II. From the 1980s, teleprinters were replaced by computers running teleprinter emulation software.
Shortwave radio is radio transmission using shortwave radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), which extends from 3–30 MHz ; above the medium frequency band (MF), to the bottom of the VHF band.
Citizens band radio, used in many countries, is a land mobile radio system, a system allowing short-distance person-to-person bidirectional voice communication between individuals, using two way radios operating on 40 channels near 27 MHz (11 m) in the high frequency band. Citizens band is distinct from other personal radio service allocations such as FRS, GMRS, MURS, UHF CB and the Amateur Radio Service. In many countries, CB operation does not require a license, and it may be used for business or personal communications. Like many other land mobile radio services, multiple radios in a local area share a single frequency channel, but only one can transmit at a time. The radio is normally in receive mode to receive transmissions of other radios on the channel; when users want to talk they press a "push to talk" button on their radio, which turns on their transmitter. Users on a channel must take turns talking. Transmitter power is limited to 4 watts in the US and the EU. CB radios have a range of about 3 miles (4.8 km) to 20 miles (32 km) depending on terrain, for line of sight communication; however, various radio propagation conditions may intermittently allow communication over much greater distances.
The FM broadcast band is a range of radio frequencies used for FM broadcasting by radio stations. The range of frequencies used differs between different parts of the world. In Europe and Africa and in Australia, it spans from 87.5 to 108 megahertz (MHz) - also known as VHF Band II - while in the Americas it ranges from 88 to 108 MHz. The FM broadcast band in Japan uses 76 to 95 MHz. The International Radio and Television Organisation (OIRT) band in Eastern Europe is from 65.8 to 74.0 MHz, although these countries now primarily use the 87.5 to 108 MHz band, as in the case of Russia. Some other countries have already discontinued the OIRT band and have changed to the 87.5 to 108 MHz band.
PSK31 or "Phase Shift Keying, 31 Baud", also BPSK31 and QPSK31, is a popular computer-sound card-generated radioteletype mode, used primarily by amateur radio operators to conduct real-time keyboard-to-keyboard chat, most often using frequencies in the high frequency amateur radio bands (near-shortwave). PSK31 is distinguished from other digital modes in that it is specifically tuned to have a data rate close to typing speed, and has an extremely narrow bandwidth, allowing many conversations in the same bandwidth as a single voice channel. This narrow bandwidth makes better use of the RF energy in a very narrow space thus allowing relatively low-power equipment to communicate globally using the same skywave propagation used by shortwave radio stations.
A DX-pedition is an expedition to what is considered an exotic place by amateur radio operators and DX listeners, perhaps because of its remoteness, access restrictions or simply because there are very few radio amateurs active from that place. This could be an island, a country, or even a particular spot on a geographical grid. "DX" is a telegraphic shorthand for "distance" or "distant".
The 2-meter amateur radio band is a portion of the VHF radio spectrum, comprising frequencies stretching from 144 MHz to 148 MHz in International Telecommunication Union region (ITU) Regions 2 and 3 and from 144 MHz to 146 MHz in ITU Region 1. The license privileges of amateur radio operators include the use of frequencies within this band for telecommunication, usually conducted locally within a range of about 100 miles (160 km).
The 6-meter band is the lowest portion of the very high frequency (VHF) radio spectrum allocated to amateur radio use. The term refers to the average signal wavelength of 6 meters.
160-meter band refers to the band of radio frequencies between 1.8 and 2 MHz, just above the medium wave broadcast band. For many decades the lowest radio frequency band allocated for use by amateur radio, before the adoption, at the beginning of the 21st century in most countries, of the 630- and 2200-meter bands. Amateur operators often refer to 160 meters as the Top Band It is also sometimes referred to as the "Gentleman's Band" in contrast to the often-freewheeling activity in the 80- and 20-meter bands.
The 80-meter or 3.5 MHz band is a band of radio frequencies allocated for amateur radio use, from 3.5 to 4.0 MHz in IARU Region 2, and generally 3.5 to 3.8 or 3.9 MHz in Regions 1 and 3 respectively. The upper portion of the band, which is usually used for phone (voice), is sometimes referred to as 75 meters. In Europe, 75m is a shortwave broadcast band, with a number of national radio services operating between 3.9 and 4.0 MHz.
The 40-meter or 7-MHz band is an amateur radio frequency band, spanning 7.000-7.300 MHz in ITU Region 2, and 7.000-7.200 MHz in Regions 1 & 3. It is allocated to radio amateurs worldwide on a primary basis; however, only 7.000-7.100 MHz is exclusively allocated to amateur radio worldwide. Shortwave broadcasters and land mobile users also have primary allocations in some countries, and amateur stations must share the band with these users.
Contesting is a competitive activity pursued by amateur radio operators. In a contest, an amateur radio station, which may be operated by an individual or a team, seeks to contact as many other amateur radio stations as possible in a given period of time and exchange information. Rules for each competition define the amateur radio bands, the mode of communication that may be used, and the kind of information that must be exchanged. The contacts made during the contest contribute to a score by which stations are ranked. Contest sponsors publish the results in magazines and on web sites.
Contest logging software refers to specialized computer software programs designed for use by competitors in amateur radio contesting. Most contest logging software is written by individual programmers who are active radio contesters.
The sport of amateur radio contesting has been responsible for the development of contesting technology specific to the sport. The most competitive stations participating in contests employ new and innovative technology, hardware, and software. Some of these innovations are exclusively used in the sport of contesting; others have seen wider application in amateur radio at large.
Amateur radio frequency allocation is done by national telecommunication authorities. Globally, the International Telecommunication Union (ITU) oversees how much radio spectrum is set aside for amateur radio transmissions. Individual amateur stations are free to use any frequency within authorized frequency ranges; authorized bands may vary by the class of the station license.
Single operator two radios (SO2R) is an operating practice employed by some competitors in the sport of amateur radio contesting. By using two transceivers attached to separate antennas, competitors can listen to one amateur radio band while transmitting on another. This capability enables the operator to more efficiently locate other amateur radio stations participating in the competition with which to make contact and score points.
An amateur radio station is a radio station designed to provide radiocommunications in the amateur radio service for an amateur radio operator. Radio amateurs build and operate several types of amateur radio stations, including fixed ground stations, mobile stations, space stations, and temporary field stations. A slang term often used for an amateur station's location is the shack, named after the small enclosures added to the upperworks of naval ships to hold early radio equipment and batteries.
An amateur radio operating award is earned by an amateur radio operator for establishing two-way communication with other amateur radio stations. It is often also called contesting. Contesting usually involves a competition to see who can contact the most stations in a set period of time on certain bands and within specific rules. Awards are sponsored by national amateur radio societies, radio enthusiast magazines, or amateur radio clubs, and aim to promote activity on the amateur radio bands. Each award has its own set of rules and fees. Some awards require the amateur radio operator to have contacted other stations in a certain number of countries, Maidenhead grid locators, or counties. Because amateur radio operators are forbidden by regulation to accept financial compensation for their on-air activity, award recipients generally only receive a certificate, wooden plaque, or a small trophy as recognition of their award.
An amateur radio repeater is an electronic device that receives a weak or low-level amateur radio signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. Many repeaters are located on hilltops or on tall buildings as the higher location increases their coverage area, sometimes referred to as the radio horizon, or "footprint". Amateur radio repeaters are similar in concept to those used by public safety entities, businesses, government, military, and more. Amateur radio repeaters may even use commercially packaged repeater systems that have been adjusted to operate within amateur radio frequency bands, but more often amateur repeaters are assembled from receivers, transmitters, controllers, power supplies, antennas, and other components, from various sources.
The World Administrative Radio Conference (WARC) bands are three portions of the shortwave radio spectrum used by licensed and/or certified amateur radio operators. They consist of 30 meters (10.100–10.150 MHz), 17 meters (18.068–18.168 MHz) and 12 meters (24.890–24.990 MHz). They were named after the World Administrative Radio Conference, which in 1979 created a worldwide allocation of these bands for amateur use. The bands were opened for use in the early 1980s. Due to their relatively small bandwidth of 100 kHz or less, there is a gentlemen's agreement that the WARC bands may not be used for general contesting. This agreement has been codified in official recommendations, such as the IARU Region 1 HF Manager's Handbook, which states: "Contest activity shall not take place on the 10, 18, and 24 MHz bands."
