Homebrew is an amateur radio slang term for home-built, noncommercial radio equipment. [1] Design and construction of equipment from first principles is valued by amateur radio hobbyists, known as "hams", for educational value, and to allow experimentation and development of techniques or levels of performance not readily available as commercial products. Some items can be home-brewed at similar or lower cost than purchased equivalents.
In the early years of amateur radio, long before factory-built gear was easily available, hams built their own transmitting and receiving equipment, known as homebrewing. [2] In the 1930s, 40s, and 50s, hams handcrafted reasonable-quality vacuum tube-based transmitters and receivers which were often housed in their basements, and it was common for a well-built "homebrew rig" to cover all the high frequency bands (1.8 to 30 MHz). After WWII ended, surplus material (transmitters/receivers, etc.), was readily available, providing previously unavailable material at costs low enough for amateur experimental use. [3]
Homebrewing was often encouraged by amateur radio publications. In 1950, CQ Amateur Radio Magazine announced a ‘‘$1000 Cash Prize ‘Home Brew’ Contest’’ and called independently-built equipment ‘‘the type of gear which has helped to make amateur radio our greatest reservoir of technical proficiency.’’ The magazine tried to steer hams back into building by sponsoring such competitions and by publishing more construction plans, saying that homebrewing imparted a powerful technical mastery to hams. In 1958, a CQ editorial opined that if ham radio lost status as a technical activity, it might also lose the privilege of operating on the public airwaves, saying, ‘‘As our ranks of home constructors thin we also fall to a lower technical level as a group’’. [4]
In the 1950s and 60s, some hams turned to constructing their stations from kits sold by Heathkit, Eico, EF Johnson, Allied Radio's Knight-Kit, World Radio Laboratories and other suppliers. [5]
Today, only a minority of hams own and operate completely homebrew or kit-built amateur stations. However, there are many new ham radio kit suppliers, and the "art" of homebrewing is alive and thriving. [2]
Homebrewing differs from kit-building in that "homebrew" connotes the process of constructing equipment using parts and designs gathered from varied and often improvised sources. Even the most skilled homebrewer may not have time or resources to build the equivalent of modern commercially made amateur radio gear from scratch, as the commercial units contain custom integrated circuits, custom cabinets, and are the result of multiple prototypes and exhaustive testing. However, constructing one's own equipment using relatively simple designs and easily obtainable or junk box electronic components is still possible. [6] Homebrew enthusiasts say that building one's own radio equipment is fun and gives them the satisfaction that comes from mastering electronic knowledge. [7]
QRPers are ham radio enthusiasts known to use a power output of five watts, sometimes operating with as little as 100 milliwatts or even less. Extremely low power—one watt and below—is often referred to by hobbyists as QRPp. Commercial transceivers designed to operate at or near-QRP power levels have been available for many years, but some QRPers prefer to design and build their own equipment, either from kits or from scratch. Some have built miniature transmitters and transceivers into Altoids boxes and operate using battery power. [8] Popular QRP kit models include the Elecraft K2, KX1, and now KX3 and those produced by NorCal, Small Wonder Labs, and others. QRP activity can often be heard on 7.030 MHz. [9]
"Glowbug" is a term used by US amateurs to describe a simple home-made tube-type radio set, reminiscent of the shortwave radio-building craze of the 1920s and 30s. Generally, any small, home-built tube-type transmitter or receiver may be referred to as a glowbug. The majority of glowbug transmitters are designed to be used in the CW radiotelegraphy mode. A number of radio amateurs also build their own tube receivers and AM voice transmitters. [9]
As late as the 1960s, glowbugs were part of many beginner ham stations because of their simple, tube-based designs. Glowbugs are popular among QRP enthusiasts and others with a penchant for constructing their own equipment. Enthusiasts may assemble glowbugs on steel chassis, tin cakepans, and wooden boards. Glowbug enthusiasts can often be heard communicating on the shortwave bands via CW using Morse code. Simple oscillators for this frequency can be built with common NTSC color burst oscillator crystals, which operate at 3.5795 MHz. [10]
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Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the amplitude of the wave is varied in proportion to that of the message signal, such as an audio signal. This technique contrasts with angle modulation, in which either the frequency of the carrier wave is varied, as in frequency modulation, or its phase, as in phase modulation.
In digital radio, packet radio is the application of packet switching techniques to digital radio communications. Packet radio uses a packet switching protocol as opposed to circuit switching or message switching protocols to transmit digital data via a radio communication link. Packet radio can be differentiated from other digital radio switching schemes by the following attributes:
In amateur radio, QRP operation refers to transmitting at reduced power while attempting to maximize one's effective range. QRP operation is a specialized pursuit within the hobby that was first popularized in the early 1920s. QRP operators generally limit their transmitted RF output power to 5 Watts or less regardless of mode be it CW operation or SSB operation.
The American Radio Relay League (ARRL) is the largest membership association of amateur radio enthusiasts in the United States. ARRL is a non-profit organization, and was co-founded on April 6, 1914, by Hiram Percy Maxim and Clarence D. Tuska of Hartford, Connecticut. The ARRL represents the interests of amateur radio operators before federal regulatory bodies, provides technical advice and assistance to amateur radio enthusiasts, supports a number of educational programs and sponsors emergency communications service throughout the country. The ARRL has approximately 161,000 members. In addition to members in the US, the organization claims over 7,000 members in other countries. The ARRL publishes many books and a monthly membership journal called QST.
Amateur television (ATV) is the transmission of broadcast quality video and audio over the wide range of frequencies of radio waves allocated for radio amateur (Ham) use. ATV is used for non-commercial experimentation, pleasure, and public service events. Ham TV stations were on the air in many cities before commercial television stations came on the air. Various transmission standards are used, these include the broadcast transmission standards of NTSC in North America and Japan, and PAL or SECAM elsewhere, utilizing the full refresh rates of those standards. ATV includes the study of building of such transmitters and receivers, and the study of radio propagation of signals travelling between transmitting and receiving stations.
Heathkit is the brand name of kits and other electronic products produced and marketed by the Heath Company. The products over the decades have included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, robots, electronic ignition conversion modules for early model cars with point style ignitions, and the influential Heath H-8, H-89, and H-11 hobbyist computers, which were sold in kit form for assembly by the purchaser.
Icom Inc. is a Japanese manufacturer of radio transmitting and receiving equipment, founded in 1954 by Tokuzo Inoue with the company's original name being "Inoue". Its products now include equipment for radio amateurs, pilots, maritime applications, land mobile professional applications and radio scanner enthusiasts.
CQ is a code used by wireless operators, particularly those communicating in Morse code,, but also by voice operators, to make a general call. Transmitting the letters CQ on a particular radio frequency is an invitation for any operators listening on that frequency to respond. It is still widely used in amateur radio.
The Hallicrafters Company manufactured, marketed, and sold radio equipment, and to a lesser extent televisions and phonographs, beginning in 1932. The company was founded by William J. Halligan and based in Chicago, Illinois, United States.
DXing is the hobby of receiving and identifying distant radio or television signals, or making two-way radio contact with distant stations in amateur radio, citizens' band radio or other two-way radio communications. Many DXers also attempt to obtain written verifications of reception or contact, sometimes referred to as "QSLs" or "veries". The name of the hobby comes from DX, telegraphic shorthand for "distance" or "distant".
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.
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.
A radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. Radio waves are electromagnetic waves with frequencies between about 30 Hz and 300 GHz. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves. Transmitters are necessary parts of all systems that use radio: radio and television broadcasting, cell phones, wireless networks, radar, two way radios like walkie talkies, radio navigation systems like GPS, remote entry systems, among numerous other uses.
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.
Vintage amateur radio is a subset of amateur radio hobby where enthusiasts collect, restore, preserve, build, and operate amateur radio equipment from bygone years, such as those using vacuum tube technology. Popular modes of operation include speaking over amplitude modulation (AM), and communicating using Morse code through continuous wave (CW) radiotelegraphy. Some enthusiasts have interest in owning, restoring and operating vintage military and commercial radio equipment such as those from 1940s to 1960s. Some undertake to construct their own gear, known in ham slang as homebrewing, using vintage parts and designs. A number of amateur radio clubs and organizations sponsor contests, events, and swap meets that cater to this specialized aspect of the hobby.
The history of amateur radio, dates from the dawn of radio communications, with published instructions for building simple wireless sets appearing at the beginning of the twentieth century. Throughout its history, amateur radio enthusiasts have made significant contributions to science, engineering, industry, and social services. Research by amateur radio operators has founded new industries, built economies, empowered nations, and saved lives in times of emergency.
Swan Electronics was a manufacturer of amateur radio gear located in Oceanside, California, United States.
The AN/PRC-6 is a walkie-talkie used by the U.S. military in the late Korean War era through the Vietnam War. Raytheon developed the RT-196/PRC-6 following World War II as a replacement for the SCR-536 "handy-talkie". The AN/PRC-6 operates using wide-band FM on a single crystal controlled frequency in the 47 to 55.4 MHz low band VHF band.
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications. The term "amateur" is used to specify "a duly authorized person interested in radioelectric practice with a purely personal aim and without pecuniary interest;" and to differentiate it from commercial broadcasting, public safety, or professional two-way radio services.
Elecraft, Inc. is an American manufacturer of amateur radio ("ham") equipment and kits, based in Watsonville, California. It was founded in 1998 by Wayne Burdick and Eric Swartz. The company's first product was the K2 transceiver; first prototyped in October 1997.
