Shortwave listening (abbreviated as SWLing) is the hobby of listening to shortwave radio broadcasts located on frequencies between 1700 kHz and 30 MHz.[1] Listeners range from casual users seeking international news and entertainment programming to hobbyists immersed in the technical aspects of radio reception and DXing. In some developing countries, shortwave listening enables remote communities to obtain regional programming traditionally provided by local medium wave broadcasters. Some estimates have placed the number of shortwave listeners worldwide in the millions.
The practice of long distance radio listening began in the 1920s when shortwave broadcasters were first established in the US and Europe. Audiences discovered that international programming was available on the shortwave bands of many consumer radio receivers, and a number of magazines and listener clubs catering to the practice arose as a result. Shortwave listening was especially popular during times of international conflict such as World War II, the Korean War and the Persian Gulf War.
Listeners use inexpensive portable "world band" radio receivers to access the shortwave bands, and some advanced hobbyists employ specialized communications receivers featuring digital technology designed for optimum reception of shortwave signals, along with outdoor antennas to enhance performance.
With the advent of the internet, many international broadcasters have scaled back or terminated their shortwave transmissions in favor of web-based program distribution, while others transition to digital broadcasting modes such as Digital Radio Mondiale that allow more efficient delivery of shortwave programming. The number of organized shortwave listening clubs has diminished along with printed magazines devoted to the hobby, however many enthusiasts continue to exchange information and news on the web.
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The precursor of shortwave listening was long distance listening in the medium wave band, where broadcasting first developed. Frank Conrad of Westinghouse, who developed the first medium wave broadcast station, KDKA in Pittsburgh, also set up the first shortwave broadcasts, as early as 1921. In 1924, the General Electric and Crosley companies started shortwave transmissions.
In the 1930s, shortwave broadcasters from the United States consisted of several private stations. The idea was to use popular American radio programs to attract audiences overseas, and thus to bring advertising revenue. But foreign audiences were difficult to measure, and were not always relevant to U.S. advertisers. During this decade, new receivers appeared on the market as well as popular shortwave magazines and clubs. Shortwave stations often offered unique QSL cards for DXers.
In Europe, shortwave broadcasts from Britain and the Netherlands began in 1927, and U.S. shortwave listeners could hear the well-organized international broadcasting efforts from Germany, Italy, the Soviet Union, Britain, and many other countries. Various well-known shortwave broadcasters became established. The BBC began as the "BBC Empire Service" in 1932 as a shortwave service.[2] Its broadcasts were aimed principally at English speakers. Radio Moscow was broadcasting on shortwave in English, French, German, Italian and Arabic by 1939. The Voice of America (or VOA) began broadcasting in 1942 as a result of the United States entry into World War II and was introduced with the Yankee Doodle theme that is still familiar to shortwave listeners.
Shortwave listening remained as an organized hobby during World War II, although in a reduced form with so many DXers in the military service or working late hours in defense industries. Most shortwave receiver manufacturers shifted to the war effort, but Zenith began its popular multiband Trans-Oceanic series in 1942. In some other countries, during the war, listening to foreign stations was a criminal offense. Established in 1939, 35-kilowatt Chinese shortwave station XGOY broadcast programming aimed at Japan, where such listening restrictions were in place. The station suffered persistent bombing that destroyed its antennas and studios.[3][4]
During the war, short messages from prisoners of war were often read by studio announcers at stations in Germany, Japan, and other Axis powers countries. Shortwave listeners copied the prisoner names and addresses and notified families by mail or telephone. Although the Allied government provided similar services, the families usually heard from shortwave listeners first, sometimes as many as 100 at a time. Listeners in other countries monitored POW messages as well, and the practice was resumed by New Zealanders during the Korean War when the voices of POWs themselves were often broadcast over Radio Peking.[5]
In the 1950s and 60s, shortwave DX columns in US magazines such as Popular Electronics "Tuning the Short Wave Bands" and Electronics Illustrated "The Listener" became news sources for serious radio listeners. Popular Electronics' "WPE Monitor Registration" program begun in 1959 even offered callsign-like identifiers to hobbyists. A number of specialty radio clubs such as the Newark News Radio Club also arose during these decades and provided hobbyists with an exchange of DX news and information. When Popular Electronics and similar magazines expanded coverage of new electronics topics in the 1970s, this led to the cancellation of several longtime shortwave listening columns.[6]
Starting with Sweden Calling DXers on Radio Sweden in 1948[7] (there was a slightly earlier short-lived program from Radio Australia), many shortwave radio stations began programs providing news for shortwave radio listeners or DXers. Some of the other prominent DX programs were Radio Netherlands' DX Jukebox (which became Media Network), the SWL Digest on Radio Canada International, and the Swiss Shortwave Merry-go-round on Swiss Radio International.
An example of notable shortwave programming was the Happy Station Show, popularly called the “world’s longest-running shortwave radio program”. Radio Netherlands broadcast the show from 1946 until it terminated in 1995. Producer and presenter Keith Perron “resurrected” Happy Station on March 12, 2009. Although no longer associated with Radio Netherlands, the new effort proclaims itself as “transmitted globally via shortwave, podcasting and Internet streaming radio”.[8]
During the Persian Gulf War in the 1990s, many Americans tuned into foreign news broadcasts on shortwave. Some electronics retailers even reported a "run" on portable shortwave receivers due to the increased interest at the time.[9]
Listening to shortwave broadcast stations for news and information programming is common, but for many shortwave listeners (abbreviated as "SWLs"), the goal is to receive as many stations from as many countries as possible, also known as DXing. "DXers" routinely test the limits of their antenna systems, radios and radio propagation knowledge. Specialized interests of shortwave listeners may include listening for shortwave utility, or "ute", transmissions such as shipping, sailing, naval, aviation, or military signals, listening for intelligence signals (numbers stations), or tuning in amateur radio stations.[1]
Listeners often obtain QSL cards from ham operators, broadcasters or utility stations as trophies of the hobby. Traditionally, listeners would send letters to the station with reception reports and requests for schedules. Many stations now accept E-mails or provide reception report forms on their Web sites. Reception reports give valuable information about propagation and interference to a station's engineers.[1]
There are several publications dedicated to providing information to shortwave listeners, including the magazines Popular Communications and Monitoring Times in the United States, and the annual publications Passport to World Band Radio (now, regrettably defunct) and the World Radio TV Handbook (WRTH). In addition, stations can provide broadcast schedules through the mail or E-mail. There are also shortwave radio programs dedicated to shortwave listening and DXing, such as the U.S. based World of Radio and DXing With Cumbre, but recently these programs have been curtailed or dropped by many international broadcasters. As of 2007, Radio Habana Cuba still hosts a program called DXers Unlimited.
While no one knows the exact number of SWLs, most estimates place the number in the millions. In 2002, according to the National Association Of Shortwave Broadcasters, for estimated numbers of households with at least one shortwave set in working order, Asia led with a large majority, followed by Europe, Sub Saharan Africa, and the former Soviet Union, respectively. The total estimated number of households worldwide with at least one shortwave set in working order was said to be 600,000,000.[10] SWLs range from teenagers to retired persons to David Letterman, who has mentioned on several occasions how much he enjoys listening to shortwave, particularly broadcasts by the British Broadcasting Corporation (BBC).[1]
In developing countries where domestic medium wave and FM networks are not as advanced as North America, Western Europe, Japan and some East Asian countries, shortwave is a means of receiving local and regional programming. In China and Russia for example, several domestic radio channels are retransmitted onto shortwave for the benefit of listeners in remote provinces. In other developing countries, shortwave listening is used as an educational tool in classrooms to expose students to foreign news, music and cultural information[11] to help improve listening comprehension, gain a native perspective and awareness of regional language variations, broaden students international worldviews, and vocabulary expansion. Poor sound reproduction, unreliable signal quality, and inflexibility of access are seen as disadvantages.[12]
Some humanitarian organizations like Ears to Our World distribute portable, self-powered shortwave radios to less developed parts of the globe, enabling people in remote, impoverished parts of the world to get educational programming, local and international news, emergency information and music. Recently, the group was involved in sending radios to Haiti so victims of the 2010 Haiti earthquake could stay abreast of local disaster recovery efforts.[8]
Radios for shortwave reception generally have higher performance than those intended for the local AM or FM broadcast band, since dependable reception of shortwave signals requires a radio with increased sensitivity, selectivity, and stability. Modern shortwave radio receivers are relatively inexpensive and easily accessible, and many hobbyists use portable "world band" receivers and built-in telescopic antennas.
Serious hobbyists may use expensive communications receivers and outdoor antenna located away from electrical noise sources, such as a dipole made from wire and insulators. Typically, a modern solid state communications receiver will be of the superheterodyne type in double, triple or, more rarely, quad conversion. It will feature multiple RF and IF amplification stages and may have at least one IF stage that is crystal controlled. It will usually have an additional BFO product detector for SSB and CW reception capabilities. The frequency coverage of receivers of this type is typically in the range of 500 kHz to 30 MHz.
The front panel controls are typically more comprehensive than those on a local broadcast receiver. Usual features include: signal strength meter; RF gain control; AVC/AGC adjustments; antenna tuner; bandwidth filters; BFO tuning; audio limiters or attenuators. Frequency display dials may either be analog (typically marked to fine increments for accuracy) or digital.[13]
The older generation of vacuum tube-based communications receivers are affectionately known as boatanchors for their large size and weight. Such receivers include the Collins R-390 and R-390A, the RCA AR-88, the Racal RA-17L and the Marconi Electra. However, even modern solid-state receivers can be very large and heavy, such as the Plessey PR2250, the Redifon R551 or the Rohde & Schwarz EK070.[14]
A feature coming into wide use in modern shortwave receivers is DSP technology, short for digital signal processing. DSP is the use of digital means to process signals, and a primary benefit in shortwave receivers is the ability to tailor the bandwidth of the receiver to current reception conditions and to the type of signal being listened to. A typical analog-only receiver may have a limited number of fixed bandwidths, or only one, but a DSP receiver may have 40 or more individually selectable filters.
Another important trend in modern shortwave listening is the use of "PC radios", or radios that are designed to be controlled by a standard personal computer. These radios as the name suggests are controlled by specialized PC software using a serial port connected to the radio. A PC radio may not have a front-panel at all, and may be designed exclusively for computer control, which reduces cost. In pure software defined radios, all filtering, modulation and signal manipulation is done in software, usually by a PC soundcard or by a dedicated piece of DSP hardware.
The rise of the internet influenced many broadcasters to cease their shortwave transmissions in favor of broadcasting over the world wide web. When BBC World Service discontinued service to Europe, North America, Australasia, and the Caribbean, it generated many protests and activist groups such as the Coalition to Save the BBC World Service.[15] In the US, the shifting of resources from shortwave to Internet and television by the Broadcasting Board of Governors, which oversees U.S. international broadcasting, has also resulted in reduced broadcasting hours in the English language. Although most of the prominent broadcasters continue to scale back their analog shortwave transmissions or completely terminate them, shortwave is still very common and active in developing regions such as parts of Africa.
Some international broadcasters have turned to a digital mode of broadcasting called Digital Radio Mondiale for their shortwave outlets. One reason is that digital shortwave broadcasts using DRM can cover the same geographic region with much less transmitter power — roughly one fifth the power — than traditional AM mode broadcasts, significantly reducing the electricity cost of operating a station. A traditional AM (analog) international shortwave station can have a power rating of 50 kilowatts to as much as one million watts per transmitter, with typical power levels in the 50–500 kilowatt range. Endorsed by the ITU, it has been approved as an international standard for digital broadcasts on the HF (shortwave) bands. A DRM broadcast rivals FM mono quality and can also send graphic images and web pages via a separate information channel.[16]
Shortwave listening also remains popular with some expatriates who tune in shortwave transmissions from their homeland. Additionally, a number of remotely controlled shortwave receivers located around the world are available to users on the web.[17] While radio hobbyists report that the number of shortwave listening clubs has diminished and printed magazines devoted to the hobby are few, enthusiasts continue to populate web sites and originate podcasts dedicated to the pursuit.[18]
Glen Hauser continues a popular web site dedicated to Shortwave Radio enthusiasts and programs.