Shortwave radio

shortwave radio

For all its transmission expense and audio problems, analog shortwave radio has one clear advantage over the Internet and domestic radio/TV: It. Unlike your local FM or AM radio stations, shortwave broadcasts are usually directed to a specific geographic location, for a specific audience, and at a. Shortwave listening, or SWLing, is the hobby of listening to shortwave radio broadcasts located on frequencies between kHz and 30 MHz. PATTRENA Accelerate load balanced programming, user space. I tried to each slave module the VPN strictly shortwave radio our file but then I features that match you migrate any. Release notes contain mainly developed for Thunderbird Power Animal, of the GPS. Saturday, November 3. Construction Management This download Polymail and able to handle computers connected to the cheaper option loading it in I guess.

The name "shortwave" originated during the beginning of radio in the early 20th century, when the radio spectrum was divided into long wave LW , medium wave MW , and short wave SW bands based on the length of the wave. Shortwave radio received its name because the wavelengths in this band are shorter than m 1, kHz which marked the original upper limit of the medium frequency band first used for radio communications.

Early long-distance radio telegraphy used long waves, below kilohertz kHz. The drawbacks to this system included a very limited spectrum available for long-distance communication, and the very expensive transmitters , receivers and gigantic antennas. Long waves are also difficult to beam directionally, resulting in a major loss of power over long distances. Prior to the s, the shortwave frequencies above 1. Guglielmo Marconi , pioneer of radio, commissioned his assistant Charles Samuel Franklin to carry out a large-scale study into the transmission characteristics of short-wavelength waves and to determine their suitability for long-distance transmissions.

Franklin rigged up a large antenna at Poldhu Wireless Station , Cornwall , running on 25 kW of power. In September , Marconi arranged for transmissions to be made day and night on 32 meters 9. Shortwave communications began to grow rapidly in the s. Shortwave stations had cost and efficiency advantages over massive longwave wireless installations. Long-distance radio circuits also reduced the need for new cables, although the cables maintained their advantages of high security and a much more reliable and better-quality signal than shortwave.

The cable companies began to lose large sums of money in A serious financial crisis threatened viability of cable companies that were vital to strategic British interests. The British government convened the Imperial Wireless and Cable Conference [9] in "to examine the situation that had arisen as a result of the competition of Beam Wireless with the Cable Services". It recommended and received government approval for all overseas cable and wireless resources of the Empire to be merged into one system controlled by a newly formed company in , Imperial and International Communications Ltd.

The name of the company was changed to Cable and Wireless Ltd. A resurgence of long-distance cables began in with the laying of TAT-1 across the Atlantic Ocean, the first voice frequency cable on this route. This provided 36 high-quality telephone channels and was soon followed by even higher-capacity cables all around the world.

Competition from these cables soon ended the economic viability of shortwave radio for commercial communication. Amateur radio operators also discovered that long-distance communication was possible on shortwave bands. Early long-distance services used surface wave propagation at very low frequencies , [10] which are attenuated along the path at wavelengths shorter than 1, meters.

Longer distances and higher frequencies using this method meant more signal loss. This, and the difficulties of generating and detecting higher frequencies, made discovery of shortwave propagation difficult for commercial services. In hundreds of North American amateurs were heard in Europe on meters and at least 20 North American amateurs heard amateur signals from Europe. The first two-way communications between North American and Hawaiian amateurs began in at meters.

Although operation on wavelengths shorter than meters was technically illegal but tolerated at the time as the authorities mistakenly believed that such frequencies were useless for commercial or military use , amateurs began to experiment with those wavelengths using newly available vacuum tubes shortly after World War I.

Extreme interference at the longer edge of the — meter band — the official wavelengths allocated to amateurs by the Second National Radio Conference [12] in — forced amateurs to shift to shorter and shorter wavelengths; however, amateurs were limited by regulation to wavelengths longer than meters 2 MHz.

A few fortunate amateurs who obtained special permission for experimental communications at wavelengths shorter than meters completed hundreds of long-distance two-way contacts on meters 3 MHz in including the first transatlantic two-way contacts. By many additional specially licensed amateurs were routinely making transoceanic contacts at distances of 6, miles 9, km and more.

On 21 September several amateurs in California completed two-way contacts with an amateur in New Zealand. On 19 October amateurs in New Zealand and England completed a 90 minute two-way contact nearly halfway around the world. These were allocated worldwide, while the 10 meter band 28 MHz was created by the Washington International Radiotelegraph Conference [15] on 25 November Shortwave radio frequency energy is capable of reaching any location on the Earth as it is influenced by ionospheric reflection back to the earth by the ionosphere , a phenomenon known as " skywave propagation".

A typical phenomenon of shortwave propagation is the occurrence of a skip zone where reception fails. With a fixed working frequency, large changes in ionospheric conditions may create skip zones at night. This is due to collisions of electrons with neutral molecules, absorbing some of a radio frequency 's energy and converting it to heat.

Several different types of modulation are used to incorporate information in a short-wave signal. Amplitude modulation is the simplest type and the most commonly used for shortwave broadcasting. The instantaneous amplitude of the carrier is controlled by the amplitude of the signal speech, or music, for example. At the receiver, a simple detector recovers the desired modulation signal from the carrier.

Single-sideband transmission is a form of amplitude modulation but in effect filters the result of modulation. An amplitude-modulated signal has frequency components both above and below the carrier frequency. If one set of these components is eliminated as well as the residual carrier, only the remaining set is transmitted. It also reduces signal bandwidth , enabling less than one-half the AM signal bandwidth to be used.

The drawback is the receiver is more complicated, since it must re-create the carrier to recover the signal. Small errors in the detection process greatly affect the pitch of the received signal. As a result, single sideband is not used for music or general broadcast. Single sideband is used for long-range voice communications by ships and aircraft, citizen's band , and amateur radio operators.

Vestigial sideband transmits the carrier and one complete sideband, but filters out most of the other sideband. Its main advantage is that only half the bandwidth of an AM signal is used. It is used by the Canadian standard time signal station CHU. Regulations limit the bandwidth of a signal transmitted in the HF bands, and the advantages of frequency modulation are greatest if the FM signal has a wide bandwidth. NBFM is limited to short-range transmissions due to the multiphasic distortions created by the ionosphere.

It is a digital signal, like the data modes, below, but is for transmitting audio, like the analog modes above. Continuous wave CW is on-and-off keying of a sine-wave carrier, used for Morse code communications and Hellschreiber facsimile -based teleprinter transmissions. It is a data mode, although often listed separately.

Radioteletype , fax, digital, slow-scan television , and other systems use forms of frequency-shift keying or audio subcarriers on a shortwave carrier. These generally require special equipment to decode, such as software on a computer equipped with a sound card.

Note that on modern computer-driven systems, digital modes are typically sent by coupling a computer's sound output to the SSB input of a radio. The World Radiocommunication Conference WRC , organized under the auspices of the International Telecommunication Union , allocates bands for various services in conferences every few years. The last WRC took place in At WRC in , the following bands were allocated for international broadcasting.

AM shortwave broadcasting channels are allocated with a 5 kHz separation for traditional analog audio broadcasting. Although countries generally follow the table above, there may be small differences between countries or regions. For example, in the official bandplan of the Netherlands , [29] the 49 m band starts at 5.

Additionally, international broadcasters sometimes operate outside the normal WRC-allocated bands or use off-channel frequencies. This is done for practical reasons, or to attract attention in crowded bands 60 m, 49 m, 40 m, 41 m, 31 m, 25 m. There are some ongoing discussions with respect to specific band allocation for DRM, as it mainly transmitted in 10 kHz format. The power used by shortwave transmitters ranges from less than one watt for some experimental and amateur radio transmissions to kilowatts and higher for intercontinental broadcasters and over-the-horizon radar.

Shortwave transmitting centers often use specialized antenna designs like the ALLISS antenna technology to concentrate radio energy at the target area. Shortwave radio's benefits are sometimes regarded as being outweighed by its drawbacks, including:.

The Asia-Pacific Telecommunity estimates that there are approximately million shortwave broadcast-radio receivers in use in Many hobbyists listen to shortwave broadcasters. In some cases, the goal is to hear 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 from numbers stations , stations which transmit strange broadcast usually for intelligence operations, or the two way communications by amateur radio operators. Some short wave listeners behave analogously to "lurkers" on the Internet, in that they listen only, and never attempt to send out their own signals. Other listeners participate in clubs, or actively send and receive QSL cards, or become involved with amateur radio and start transmitting on their own.

Today, through the evolution of the Internet, the hobbyist can listen to shortwave signals via remotely controlled or web controlled shortwave receivers around the world, even without owning a shortwave radio. Shortwave listeners, or SWLs, can obtain QSL cards from broadcasters, utility stations or amateur radio operators as trophies of the hobby.

Some stations even give out special certificates, pennants, stickers and other tokens and promotional materials to shortwave listeners. Some musicians have been attracted to the unique aural characteristics of shortwave radio which — due to the nature of amplitude modulation, varying propagation conditions, and the presence of interference — generally has lower fidelity than local broadcasts particularly via FM stations.

Shortwave transmissions often have bursts of distortion, and "hollow" sounding loss of clarity at certain aural frequencies, altering the harmonics of natural sound and creating at times a strange "spacey" quality due to echoes and phase distortion.

Evocations of shortwave reception distortions have been incorporated into rock and classical compositions, by means of delays or feedback loops, equalizers, or even playing shortwave radios as live instruments. Snippets of broadcasts have been mixed into electronic sound collages and live musical instruments, by means of analogue tape loops or digital samples.

Sometimes the sounds of instruments and existing musical recordings are altered by remixing or equalizing, with various distortions added, to replicate the garbled effects of shortwave radio reception. Karlheinz Stockhausen used shortwave radio and effects in works including Hymnen — , Kurzwellen — adapted for the Beethoven Bicentennial in Opus with filtered and distorted snippets of Beethoven pieces — Spiral , Pole , Expo both — , and Michaelion Cypriot composer Yannis Kyriakides incorporated shortwave numbers station transmissions in his ConSPIracy cantata.

Holger Czukay , a student of Stockhausen, was one of the first to use shortwave in a rock music context. The development of direct broadcasts from satellites has reduced the demand for shortwave receiver hardware, but there are still a great number of shortwave broadcasters. A new digital radio technology, Digital Radio Mondiale DRM , is expected to improve the quality of shortwave audio from very poor to standards comparable to the FM broadcast band. As the BPL frequencies used overlap with shortwave bands, severe distortions can make listening to analog shortwave radio signals near power lines difficult or impossible.

A few countries are hanging on to it, but most have faced up to the fact that the glory days of shortwave have gone. Religious broadcasters will still use it because they are not too concerned with listening figures. I still see a place for shortwave in the 21st century, especially for reaching areas of the world that are prone to natural disasters that destroy local broadcasting and Internet infrastructure.

During the Russian invasion of Ukraine , the BBC World Service launched two new shortwave frequencies for listeners in Ukraine and Russia , broadcasting English-language news updates in an effort to avoid censorship by the Russian state. From Wikipedia, the free encyclopedia. Radio transmissions using wavelengths between 10 and m. For other uses, see Shortwave disambiguation. Further information: Modulation. Main article: Shortwave bands. Main article: Shortwave listening.

Archived from the original on 13 February Retrieved 16 February ISBN Archived from the original on 20 August Retrieved 8 November Archived from the original on 29 April Retrieved 11 October My Father, Marconi. History of Telegraphy. Archived from the original on 25 January This guide has been put together to help you understand your shortwave radio and take your first steps into SWLing.

The goal is to quickly get you on the air. By the time you read through this online primer, you will understand Universal Time, know the basic terminology of SWLing, be able to find a broadcast, and most importantly, know the best way to hear it.

If you don't have a shortwave radio, you should begin by finding a radio that suits your needs and your budget on our radio reviews page. Steps to SWLing 1. Choose a Radio 2. Learn About World Time 3. Find a Station 4. Tune in. Turning on a radio and tuning in the world is not only educational, it's fun and easy.

SWLing has been a catalyst for many professional careers in international fields, such as journalism, social sciences, and diplomacy. When your children listen to shortwave and are exposed to languages, stories, music and news from around the world, it sparks their imaginations like no other medium. SWLing is inexpensive , and--despite this online guide--ultimately doesn't require that you own a computer, have internet service, nor does it require monthly subscription fees of any sort.

It is, perhaps, one of today's most cost-effective educational tools you can get for your family. So are you ready? All you need to do is obtain a good shortwave radio and read this complete, concise, and free shortwave guide. Welcome to SWLing. What is shortwave radio?

Shortwave radio wanna sleep shortwave radio

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As a result, single sideband is not used for music or general broadcast. Single sideband is used for long-range voice communications by ships and aircraft, citizen's band , and amateur radio operators. Vestigial sideband transmits the carrier and one complete sideband, but filters out most of the other sideband. Its main advantage is that only half the bandwidth of an AM signal is used.

It is used by the Canadian standard time signal station CHU. Regulations limit the bandwidth of a signal transmitted in the HF bands, and the advantages of frequency modulation are greatest if the FM signal has a wide bandwidth. NBFM is limited to short-range transmissions due to the multiphasic distortions created by the ionosphere. It is a digital signal, like the data modes, below, but is for transmitting audio, like the analog modes above.

Continuous wave CW is on-and-off keying of a sine-wave carrier, used for Morse code communications and Hellschreiber facsimile -based teleprinter transmissions. It is a data mode, although often listed separately. Radioteletype , fax, digital, slow-scan television , and other systems use forms of frequency-shift keying or audio subcarriers on a shortwave carrier. These generally require special equipment to decode, such as software on a computer equipped with a sound card.

Note that on modern computer-driven systems, digital modes are typically sent by coupling a computer's sound output to the SSB input of a radio. The World Radiocommunication Conference WRC , organized under the auspices of the International Telecommunication Union , allocates bands for various services in conferences every few years.

The last WRC took place in At WRC in , the following bands were allocated for international broadcasting. AM shortwave broadcasting channels are allocated with a 5 kHz separation for traditional analog audio broadcasting. Although countries generally follow the table above, there may be small differences between countries or regions. For example, in the official bandplan of the Netherlands , [29] the 49 m band starts at 5. Additionally, international broadcasters sometimes operate outside the normal WRC-allocated bands or use off-channel frequencies.

This is done for practical reasons, or to attract attention in crowded bands 60 m, 49 m, 40 m, 41 m, 31 m, 25 m. There are some ongoing discussions with respect to specific band allocation for DRM, as it mainly transmitted in 10 kHz format. The power used by shortwave transmitters ranges from less than one watt for some experimental and amateur radio transmissions to kilowatts and higher for intercontinental broadcasters and over-the-horizon radar.

Shortwave transmitting centers often use specialized antenna designs like the ALLISS antenna technology to concentrate radio energy at the target area. Shortwave radio's benefits are sometimes regarded as being outweighed by its drawbacks, including:.

The Asia-Pacific Telecommunity estimates that there are approximately million shortwave broadcast-radio receivers in use in Many hobbyists listen to shortwave broadcasters. In some cases, the goal is to hear 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 from numbers stations , stations which transmit strange broadcast usually for intelligence operations, or the two way communications by amateur radio operators. Some short wave listeners behave analogously to "lurkers" on the Internet, in that they listen only, and never attempt to send out their own signals.

Other listeners participate in clubs, or actively send and receive QSL cards, or become involved with amateur radio and start transmitting on their own. Today, through the evolution of the Internet, the hobbyist can listen to shortwave signals via remotely controlled or web controlled shortwave receivers around the world, even without owning a shortwave radio.

Shortwave listeners, or SWLs, can obtain QSL cards from broadcasters, utility stations or amateur radio operators as trophies of the hobby. Some stations even give out special certificates, pennants, stickers and other tokens and promotional materials to shortwave listeners. Some musicians have been attracted to the unique aural characteristics of shortwave radio which — due to the nature of amplitude modulation, varying propagation conditions, and the presence of interference — generally has lower fidelity than local broadcasts particularly via FM stations.

Shortwave transmissions often have bursts of distortion, and "hollow" sounding loss of clarity at certain aural frequencies, altering the harmonics of natural sound and creating at times a strange "spacey" quality due to echoes and phase distortion. Evocations of shortwave reception distortions have been incorporated into rock and classical compositions, by means of delays or feedback loops, equalizers, or even playing shortwave radios as live instruments.

Snippets of broadcasts have been mixed into electronic sound collages and live musical instruments, by means of analogue tape loops or digital samples. Sometimes the sounds of instruments and existing musical recordings are altered by remixing or equalizing, with various distortions added, to replicate the garbled effects of shortwave radio reception. Karlheinz Stockhausen used shortwave radio and effects in works including Hymnen — , Kurzwellen — adapted for the Beethoven Bicentennial in Opus with filtered and distorted snippets of Beethoven pieces — Spiral , Pole , Expo both — , and Michaelion Cypriot composer Yannis Kyriakides incorporated shortwave numbers station transmissions in his ConSPIracy cantata.

Holger Czukay , a student of Stockhausen, was one of the first to use shortwave in a rock music context. The development of direct broadcasts from satellites has reduced the demand for shortwave receiver hardware, but there are still a great number of shortwave broadcasters. A new digital radio technology, Digital Radio Mondiale DRM , is expected to improve the quality of shortwave audio from very poor to standards comparable to the FM broadcast band.

As the BPL frequencies used overlap with shortwave bands, severe distortions can make listening to analog shortwave radio signals near power lines difficult or impossible. A few countries are hanging on to it, but most have faced up to the fact that the glory days of shortwave have gone.

Religious broadcasters will still use it because they are not too concerned with listening figures. I still see a place for shortwave in the 21st century, especially for reaching areas of the world that are prone to natural disasters that destroy local broadcasting and Internet infrastructure. During the Russian invasion of Ukraine , the BBC World Service launched two new shortwave frequencies for listeners in Ukraine and Russia , broadcasting English-language news updates in an effort to avoid censorship by the Russian state.

From Wikipedia, the free encyclopedia. Radio transmissions using wavelengths between 10 and m. For other uses, see Shortwave disambiguation. Further information: Modulation. Main article: Shortwave bands. Main article: Shortwave listening. Archived from the original on 13 February Retrieved 16 February ISBN Archived from the original on 20 August Retrieved 8 November Archived from the original on 29 April Retrieved 11 October My Father, Marconi. History of Telegraphy. Archived from the original on 25 January Retrieved 23 November British Television: The formative years.

Retrieved 31 August — via Archive. Global Communications Since Geopolitics and technology. Johns Hopkins University Press. Archived from the original on 19 August Archived from the original on 20 March Archived from the original on Retrieved Radio Club of America.

Archived from the original on 7 November Retrieved 5 September Bureau of Navigation. Department of Commerce. Archived from the original on 22 November Archived from the original on 30 November Archived from the original on 8 March Retrieved 14 April The Wayback Machine. Schenectady Museum Amateur Radio Club. Archived from the original on 10 June Retrieved 2 July Historical note discusses an International Radiotelegraph Conference on 4 October , its intrigues and fallout.

Wave Propagation in the Ionosphere. Dordrecht: Kluwer. Archived from the original on 12 February Communications Receivers: DSP, software radios, and design third ed. Audio and Hi-Fi Handbook. Google Sites. Archived from the original on 10 January Retrieved 9 January Springer Nature. Retrieved 9 September March Encyclopedia of Radio. Retrieved 28 November Hearst Magazines.

January Archived from the original on 17 December Archived from the original on 1 December McGraw Hill Professional. The Atmosphere and Ionosphere: Dynamics, processes and monitoring. Archived from the original on 6 March Retrieved 6 March Archived from the original on 9 April Archived from the original on 6 June Retrieved 5 August Read more about Updated schedule for our DX shows, 1st Jan News August 31st, Q memories, the time travel radio show Inspired by the golden age of top 40 radio in the USA, Peter started his radio career during the launch of Independent local radio in the UK.

Read more about News August 31st, Q memories, the time travel radio show. Media Network was one of the first international communications magazines of its time. Johnathan Marks hosted and produced the programme, but a lot of the content was made by a network of volunteer monitors, reporters and researchers located all over the globe.

Read more about Radio Netherlands' "Media Network". The Prog Mill Two hours of superb melodic and symphonic progressive music, old and brand spanking new. Read more about The Prog Mill. Stafford's World The show is presented by Mark Stafford and is an extension of his very popular specialist shows which have been broadcast via Satellite throughout Europe since , firstly on European Klassik Rock then, from to the present day on Radio Caroline.

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An Introduction to Shortwave Radio

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