Shortwave International Broadcasting Amateur RadioAmateur Radio

Short wavelengths are associated with high frequencies because there is an inverse relationship between frequency and wavelength.

Shortwave frequencies are capable of reaching the other side of the planet by bouncing a signal off the ionosphere. The selection of a frequency to use to reach a target area depends on several factors:

The Asia-Pacific Telecommunity estimates that there are approximately 600,000,000 shortwave radio receivers in use in 20022002 is a common year starting on Tuesday (see link for calendar). 2002 was the first palindromic year since 1991 and the last until 2112. 2002 was also designated: International Year of Ecotourism and Mountains National Science Year in the United Kingdom.

The World Radiocommunication Conference (WRC), organized under the auspices of the International Telecommunications Union, allocates bands for various services in conferences every few years. The next WRC is scheduled to take place in 20072007 is a common year starting on Monday (see link for calendar). Predicted Events January 1 Target date for the admission of Romania and Bulgaria to the European Union. March 1 USS Baltimore to be deactivated. March 19 Partial solar eclipse June NASA's M. At the World Administrative Radio Conference (WARC) in 1997, the following bands were allocated to international broadcasters (listed in the table):

Meter Band	Frequency Range	Remarks
120 m	2,300 - 2,495 kHz	tropic band
90 m	3,200 - 3,400 kHz	tropic band
75 m	3,900 - 4,000 kHz	not in the Americas
60 m	4,750 - 5,060 kHz	tropic band
49 m	5,900 - 6,200 kHz
41 m	7,100 - 7,300 kHz	not in the Americas
41 m	7,300 - 7,350 kHz
31 m	9,400 - 9,900 kHz
25 m	11,600 - 12,100 kHz
22 m	13,570 - 13,870 kHz
19 m	15,100 - 15,800 kHz
16 m	17,480 - 17,900 kHz
15 m	18,900 - 19,020 kHz
13 m	21,450 - 21,850 kHz
11 m	25,600 - 26,100 kHz

Shortwave broadcasting channels are allocated with a 5 kHz separation. International broadcasters, however, may operate outside the normal WARC-allocated bands or use off-channel frequencies to attract attention in crowded bands.

The power used by shortwave transmitters ranges from less than one watt for some experimental transmissions to 500 kilowatts and highter for intercontinental broadcasters. Shortwave transmitting centers often use specialized antenna designs to concentrate radio energy on a bearing aimed at the target area.

1 International broadcasting

See International broadcasting for details on the history and practice of broadcasting to foreign audiences.

2 Amateur radioAmateur radio commonly called ham radio , is a hobby enjoyed by many people throughout the world; as of 2004 about 3 million worldwide, 70,000 in Germany, 5,000 in Norway, 57,000 in Canada, and 700,000 in the USA. A holder of an Amateur Radio license has

The privilege of operating shortwave radio transmitters for non-commercial purposes is open to licensed amateurs. In the USA, they are licensed by the Federal Communications CommissionThe Federal Communications Commission (FCC) is an independent United States government agency, created, directed, and empowered by Congressional statute. The FCC was established by the Communications Act of 1934 as the successor to the Federal Radio Commi (FCC). In the U.S., no license is required to own or operate shortwave receivers. Recently the FCC has added an amateur radio license which requires no knowledge of Morse code, making it easier for beginners to get involved; however, a working knowledge of Morse code is required to operate on shortwave bands.

Amateur radio operators have made numerous technical advancements in the field of radio and make themselves available to transmit emergency communications when normal communications channels fail. Some amateurs practice operating off the power grid so as to be prepared for power loss.

3 Shortwave listening

Many hobbyists listen to shortwave broadcasters without operating transmitters. In many cases, the goal is to obtain as many stations from as many countries as possible (DXing); others listen to specialized shortwave utility, or "ute", transmissions such as maritime, naval, aviation, or military signals. Others focus on intelligence signals.

Shortwave listeners, or SWLs, can obtain "QSL" cards from broadcasters or utility stations as trophies of the hobby.

4 Numbers stations

Numbers stations are shortwave radio stations of uncertain origin that broadcast streams of numbers, words, or phonetic sounds. Although officially there is no indication of their origin, radio hobbyists have determined that many of them are used by intelligence services as one-way communication to agents in other countries.

5 Shortwave's future

The development of direct broadcasts from satellites has reduced the demand for shortwave receivers, but there are still a great number of shortwave broadcasters. A new digital radio technology, Digital Radio Mondiale, is expected to improve the quality of shortwave audio from very poor to standards comparable to the FM broadcast band. The future of shortwave radio is threatened by the uprise of power line communication (PLC), also known as Broadband over Power Lines (BPL), where a data stream is transmitted over unshielded power lines. As the frequencies used overlap with the shortwave bands severe distortions make listening to shortwave radio near power lines difficult or impossible.

6 Shortwave broadcasts and music

Some musicians have been attracted to the unique aural qualities of shortwave radio. John Cage employed shortwave radios as live instruments in a number of pieces, and other musicians have sampled broadcasts, used tape loops of broadcasts, or drawn inspiration from the unusual sounds on some frequencies. Karlheinz Stockhausen used shortwave radio in works including Telemusik (1966), Hymnen (1966-67) and Spiral (1968), and Holger Czukay, Pat Metheny, Aphex Twin, Boards of Canada, Meat Beat Manifesto, and Wilco have also used or been inspired by broadcasts.

Radio spectrum

ELF | SLF | ULF | VLF | LF/ LW | MF/ MW | HF/ SW | VHF | UHF | SHF | EHF

3 Hz | 30 Hz | 300 Hz | 3 kHz | 30 kHz | 300 kHz | 3 MHz | 30 MHz | 300 MHz | 3 GHz | 30 GHz | 300 GHz

Radio spectrum International broadcasting Mass media

<Hide>

Home > Shortwave