Shortwave radio operates in the frequency range of 3,000 kHz to 30,000 kHz (3–30 MHz). Because they can be refracted by the ionosphere, shortwave frequencies are capable of reaching any location on the Earth.
The power used by shortwave transmitters ranges from less than one watt, for some experimental and amateur radio transmissions, to 500 kilowatts and higher, for intercontinental broadcasters and over-the-horizon radar. DRM, the new digital audio broadcasting format for shortwave, operates 10 kHz or 20 kHz channels. There are some ongoing discussions with respect to specific band allocation for DRM, as it mainly transmitted in 10 kHz format.
Typical Shortwave Applications include:
- Domestic broadcasting
- International broadcasting
- Specialty political, religious, and conspiracy theory radio networks, individual commercial and non-commercial paid broadcasts
- Utility stations transmitting messages not intended for the general public, such as aircraft flying between continents, encoded or ciphered diplomatic messages, weather reporting, or ships at sea
- Clandestine stations
- Amateur radio operators
- Time signal stations
Shortwave possesses a number of advantages over newer technologies, including:
- The difficulty in censoring programming by authorities in target countries. Unlike the Internet, government authorities cannot monitor which stations (sites) are being listened to (accessed).
- Low-cost shortwave radios are widely available in all but the most repressive countries in the world.
- In many countries (particularly in most third world nations and in the Eastern bloc during the Cold War era) ownership of shortwave receivers is widespread. In many of these countries some domestic stations also used shortwave.
- Many newer shortwave receivers are portable and can be battery operated, making them useful in difficult circumstances. Newer technology includes hand-cranked radios which provide power for a short time.
- Shortwave radios can be used in situations where Internet or satellite technology is unavailable (or unaffordable).
- Shortwave radio travels much farther than FM. Shortwave broadcasts can be heard from all parts of the world, in all parts of the world.
Richardson Electronics has been supporting the largest shortwave broadcasters in the world for decades with a variety of products (see below) and value-added services. These services include full technical support, which includes:
- Retrofitting to more efficient tube-based transmission system
- Retrofitting to higher power level transmitter systems
Shortwave products available from Richardson Electronics include:
- New & Rebuilt Power Grid Tubes
- Finger Stock
- Vacuum Capacitors
- Vacuum Contactors
Richardson Electronics can offer tube and capacitor products for operation in most of the common shortwave transmitters, including models such as:
- Continental Electronics