Shortwave listening
Shortwave listening, or SWLing, is the hobby of listening to shortwave radio broadcasts located on frequencies between 1700 kHz and 30 MHz (30 000 kHz).[1] Listeners range from casual users seeking international news and entertainment programming, to hobbyists immersed in the technical aspects of long-distance radio reception and sending and collecting official confirmations (QSL cards) that document their reception of remote broadcasts (DXing). In some developing countries, shortwave listening enables remote communities to obtain regional programming traditionally provided by local medium wave AM broadcasters. In 2002, the number of households that were capable of shortwave listening was estimated to be in the hundreds of millions.[2]
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, and the BBC resumed transmission during the 2022 Russian invasion of Ukraine.[3]
Listeners use inexpensive portable world band receivers to access the shortwave bands, and some advanced hobbyists employ specialized shortwave communications receivers featuring digital technology as well as Digital signal processing designed for optimum reception of shortwave signals, along with outdoor antennas to enhance performance. Many hobbyists also choose to use Software-defined radio receivers for their benefits over traditional radios.
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 are moving from traditional analog to digital broadcasting modes in order to 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.
Future of shortwave listening[edit]
The rise of the Internet has resulted in many broadcasters ceasing their shortwave transmissions in favor of broadcasting over the World Wide Web.[19] 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.[20] A number of traditionally prominent shortwave broadcasters have disappeared or cut back their operations, with Radio Moscow, Radio Netherlands, Rai Italia Radio, and Radio Australia among those that have ceased broadcasting on shortwave.[21][22] Although most of the major broadcasters continue to scale back their analog shortwave transmissions or completely terminate them, shortwave is still active in developing regions such as parts of Africa, South Asia and Latin America.[19]
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 — 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 1000 kilowatts 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.[23]
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.[24] While radio hobbyists report that the number of shortwave listening clubs has diminished and printed magazines devoted to the hobby are few, enthusiasts such as Glenn Hauser and others continue to populate web sites, and originate podcasts dedicated to the pursuit.[25]