In the early 20th century, during the beginning of radio history, the radio spectrum was divided into three radio waves, the long (LW), the medium (MW), and the short wave (SW) band, based on their wavelengths.
Early long-distance telegraphy used long waves, with the transmitter power below 300 kHz, but it required very expensive transmitters, receivers, and huge antennas. Furthermore, long waves are also very difficult to beam directionally, resulting in loss of power over long distances.
Shortwaves, as technology, was initially invented to aid long-distance communication for people at sea and has proved itself simple and cheap to operate. While the technology has been around for a long time, it wasn’t until 1920 when shortwave radio began to become popular thanks to the ingenuity of radio amateur Guglielmo Marconi who uncovered its potential just before the First World War.
This article will go over what SW radio is, its history, shortwave radio bands, and its technology. Furthermore, this article will discuss the need for this arguably dying form of radio communication and its most common uses.
What is Shortwave Radio?
Shortwave radio received its name because the wavelengths in this band are shorter than 1500 kHz, which marked the upper limit of the medium frequency band. It’s not only used by international radio stations and radio amateurs, but is a huge part of aviation, marine, diplomatic, and emergency purposes.
Shortwave radio is a radio broadcast similar to the common AM and FM, only that private companies own AM and FM radio stations, while the government operates most shortwave radio stations. Additionally, shortwave radios broadcast on different frequencies, allowing transmissions to travel around the world. This means you can pick up or listen to broadcasts from virtually anywhere, thanks to their worldwide audiences.
Shortwave stations are the most convenient way to reach marginalized regions with poor phone service. Although they reach distant areas, the clarity of the stations can sometimes be challenging as they are susceptible to the sun’s electrical interference. For this reason, most stations usually request their shortwave listeners to send them reception reports to identify how the shortwave broadcasts are being received in different regions.
Aside from international communication, shortwave radios are also ideal for diplomatic communication and over-the-horizon radar. Shortwave enthusiasts also use these devices as a hobby.
Shortwave radios provide popular entertainment and major urgent news in most parts of the world except the most developed continents like Europe, Japan, and North America. These continents’ commercial and government programming is transmitted with other frequency bands.
Aside from international broadcasting, shortwave is also used in long-distance telegraph and telephone communications. Handheld or portable two-way radios and Amateur radio stations utilize shortwave frequencies to transmit information.
History of Shortwave Radio
In short, Guglielmo Marconi should be credited for the shortwave radio invention. Since 1895, Marconi has been actively involved in wireless communication. His England-based company started out developing and implementing wireless telegraphs worldwide.
By 1899, Gugliemo could transmit English channel signals across Britain and France. Due to continuous experiments, he could transmit wireless signals up to 2100 miles across the Atlantic Ocean by 1901.
In 1923, Gugliemo and his assistant, Charles Franklin, started investigating the shortwave propagations characteristics. They wanted to know if these waves could allow clear, long-distance communications, regardless of the time of day or season. His main goal was to invent a lifesaving technology to help people at sea.
Gugliemo and Franklin built a transmitter at Poldhu, Cornwall, of about 12 kilowatts, operating at the ninety-two-meter band. This was the most robust short-wave transmitter built up to that time. To test the transmitter’s strength, they attached a receiver on a yacht and sailed towards West Africa.
By July 1923, Marconi and Franklin had made their first radio contact at Capo Verde Island. Their second radio contact was at the Beirut port in Lebanon, at an 11MHz frequency both day and night, which was impressive then.
Through this test, Marconi concluded that shortwaves bounced off the atmosphere’s top layer and landed on a distant region, unlike long waves that curved along the earth’s barriers. This is because the signals weren’t noticeable immediately after departure.
Early 1924. Marconi’s employees built receivers in North and South America, Australia, India, and South Africa. By April and May, the receivers picked up the Cornwall transmitter signal. After several experiments and improvements, the idea of shortwave radio was birthed.
The number of shortwave radio broadcasters snowballed immediately after Marconi’s invention. By the end of 1928, about half of all long-distance communications were via shortwave. The other half was delivered through longwave systems and submarine cables.
Shortwave or ‘beam’ radio, as it was commonly known at the time, was one of the most prominent Marconi technical successes. It was also incredibly cheap than the longwave stations. Shortwave prices were only one-tenth of the longwave charges.
By this time, shortwave radio could transmit up to two hundred words per minute, which was way faster than long waves and loaded cable systems. For this reason, shortwave radio use skyrocketed for a long period, drastically reducing longwave radio communications.
Submarine cable systems continued operating alongside the shortwave radios during this period. This is because they were equally reliable and functioned during the day and night. Unlike the shortwave radios, the storm hardly influenced cable systems’ effectiveness.
Shortwave radio use is declining due to low bandwidth and unimpressive sound quality. The rise of digital technology has also contributed to reducing its demand significantly. However, it is still used in various world regions as a reliable form of communication. For instance, amateur radios continue relying on shortwave radio for their communications. Marconi’s invention is also used in military applications and global navigation systems. His legacy will forever be remembered in the world of radio communications.
Marconi’s invention revolutionized maritime and global communication. The shortwave radio allowed ships to communicate with each other and relay distress messages across vast distances, connecting distant continents separated by oceans and seas. This technology was a crucial breakthrough in lifesaving, allowing sailors to ask for help and be rescued quickly in times of need. It changed how ships communicated with each other, helping people at sea avoid danger and remain safe.
Shortwave systems had to pave the way after the invention of TELSTAR, the first satellite, and increased space communication sharing.
What is it used for?
SW radios are commonly used for international broadcasting, primarily by government-sponsored broadcasts, international news (like BBC World Service, founded in 1932 in the United Kingdom), or cultural shortwave stations. Amateur radio operators often use shortwave bands after receiving the right license from the government (most likely the FCC – Federal Communications Commission).
Domestic shortwave broadcasting is also common, mostly to big populations with few longwave, mediumwave, or FM stations available. It is used for political, religious, and alternative media coverage and individual commercial paid broadcasts.
Due to the shortwave’s ability to operate in the worst weather conditions, the radio has many practical uses where other technology proved inferior.
Longwaves weaken with distance, making them unreliable for maritime communication. Besides reaching significant wavelengths, shortwaves offer persons at sea a more comprehensive frequency range.
Although most ships switched to satellite communication, some have stuck to shortwave transmissions. Unlike satellite communication, which is specifically built on the ship, shortwaves are common for both the receiver and transmitter. This makes them more reliable in urgent times.
Oceanic air traffic control also uses HF bands for long-distance communications with ships that are beyond the range of traditional VHF frequencies.
A “utility station” uses shortwave radio frequencies to transmit messages not intended for the public, like marine weather, ship-to-shore shortwave stations, and more. This is exclusively for long-distance, governmental and non-broadcast communications.
Amateur radios rely on shortwave radio frequencies to transmit information. Ham radio operators use these devices mainly for recreational long-distance communication. These handheld radios are also reliable in marginalized regions with no phone coverage.
Since ham radios primarily act as a hobby, amateur radio enthusiasts could create and run individual radio stations to connect with other enthusiasts. They share knowledge, news, stories, and more. And while for a listener, the FM radio proves to be more efficient and less difficult to access, the experience of using amateur radios within close-knit communities cannot be beaten. The most widely known communities can be found through websites like the National Association for Amateur Radio (ARRL).
Ham radio lovers use these handheld communication devices to transmit music, sports broadcasting, and even for personal learning.
Aside from reaching all ends of the earth and surviving various climate conditions, shortwave radios are pretty handy in times of disaster.
Most electronically-powered infrastructure may be destroyed during disasters, hindering internet connection and clear communication.
Shortwave radios will give you different perspectives on emerging world issues thanks to the multiple stations. With the inclusivity of various local language-based stations, shortwave radios can reach a larger audience during urgent, desperate times.
Listening to Shortwave Radio
Audiences around the world discovered that international, uncensored shortwave radio programming was available on the SW bands of many consumer radio receivers. Magazines, articles, and listener clubs were all involved in the golden age of SW radio. Listening to these shortwave frequency bands was especially popular during international conflicts like the Korean War, World War II, and the Persian Gulf War.
For tech-savvies and amateur radio enthusiasts, SW is one of the most exciting hobbies as a listener. Usually, the goal is to reach as many shortwave signals from as many countries as possible. Today hobbyists can listen to multiple shortwave broadcasts with remote-controlled or web-controlled receivers, even without owning a shortwave radio device.
Listeners can obtain official confirmations that document the reception of distant broadcasts (i.e. QSL cards) from broadcasters and amateur radio operators, as trophies of the hobby. Some shortwave radio stations even give out certificates, pennants, stickers, and other small tokens to their listeners.
The largest shortwave audiences tune in for broadcasts open to the general public through well-known broadcasting stations like China Radio International, Voice of America, BBC World Service, etc.
With the advent of the world wide web, most international broadcasters scaled back or completely terminated their SW transmission in favor of web-based programs. Others are moving on to digital broadcasting modes in order to achieve more efficient and high-quality transmission of SW programming. Today, computer and internet access gives any user free access to over 100 shortwave receivers without censorship or monitoring. Most SW radio broadcasters like WSPR have their own websites with stories, frequencies, channels, news, and other useful information for listeners around the world.
While most people think this technology is a dying form of radio programming, there are still a lot of advantages of shortwave radio over newer technologies.
The most commonly known advantage is the difficulty of censoring by authorities. While government authorities have no problem censoring and monitoring content on the internet, they face technical difficulties monitoring which stations are being accessed. The most well-known example of this is the attempted coup against Soviet President Mikhail Gorbachev when his access to any means of communications was limited, and the only way to stay in contact and informed was through the BBC World Service on shortwave radio frequencies.
Low-cost portable shortwave devices are widely available, and simple shortwave receivers can easily be built with only a few parts. Most newer shortwave receivers are portable and battery-operated, making shortwave communications very handy and possibly life-saving in difficult situations when reception fails (natural disasters, war zones, etc.). There are times when the internet fails, is shut off, or censored. Through SW radio, nearly every piece of information is available without the need for the internet or a computer. This medium of communication was one of the main ways of contacting anyone during times of war and disasters, so these devices are a crucial part of our history and everyday lives even today.
A lot of countries (mostly developing nations) still use shortwave radio as their main way of broadcasting any content. Shortwave radios have a larger range than FM (frequency modulation radios), and broadcasts can be easily transmitted over a distance of several thousand kilometers. Many tropical regions use shortwave radio as well, because it’s less prone to interference from thunderstorms, covers a large area, and uses low power.
Shortwave radio is one of the most robust means of communication, and can only be disrupted by interference or bad ionospheric conditions. Participants only need a pair of transceivers with antennas and a source of energy.
Disadvantages shrink in comparison to the shortwave radio’s advantages. The biggest setback of shortwave is that in most Western countries, it’s only used by true enthusiasts in order to study and experiment with radio technology, as the stations that are worth listening to don’t use this wavelength and these frequencies anymore. Also, in urban areas, more interfering factors make its usage difficult.
Does Shortwave Radio has a Future?
In the past decades, SW has become digital, meaning a more efficient transmission and significant energy savings compared to the old analog. A lot of countries in Latin America use shortwave radio, the most commonly known being Argentina’s shortwave broadcasting.
The international shortwave program meant that a lot of people were able to access free information. But many of these international shortwave broadcasters were expensive and used a lot of energy for this frequency band that “knew no border”, ranging from 1.7 Mhz to the end of the HF band.
To this day, BBC World Service and many other international broadcasters are still on shortwave and have a huge audience, mainly because BBC introduced new shortwave transmissions in additional languages. Also, in Australia, there are wide consultations about reintroducing shortwaves for the Pacific Islands. Radio China has also upgraded some of its shortwave transmitters for domestic use and is now covering the whole country with digital (DRM) shortwave radio signals.
DRM stands for Digital Rights Management. It was established in 1983 as Software Service System (SSS). DRM is the most suitable option for shortwave, as it has good digital quality and reaches great distances without any fading or crackling sounds, creating a much better listening experience with higher sound quality. DRM is a systematic approach to copyright protection.
The purpose of DRM is to prevent redistribution and restrict how consumers can copy purchased content. A DRM broadcast rivals FM quality and can also send graphic images and websites via separate information channels. While the golden age of analog shortwave broadcasting is possibly over, the band still has great potential and many important roles.
The future of SW is widely discussed. Every article has a different stand, and news about it varies. But whether an article or an expert is for or against the use of this technology, one thing always stays the same. It is undeniable that the use of such devices and currently dying technology was a huge part of our history. It has saved lives during wars, and even today, in times of disaster and worldwide conflicts, SW devices are most possibly our only hope for communication.
Shortwave radio technology has been around for over a hundred years. Although its use may have reduced over time, these devices continue operating in some continents thanks to their massive benefits. With its rich history, shortwave radio technology will continue to exist, making it an essential communication piece of every organization.
The advancement in this sector is also taking shape with the introduction of new broadcasters and devices. These radios are reliable, versatile, and cost-effective for any user. With such benefits, shortwave radios could remain relevant for many years.
I have been a SWL listener since 1970 and have logged over sixty countries, not a stellar accomplishment, but a source of great enrichment. I have used tabletops and portable radios with much success. I was disappointed that the major broadcasters shut down, and although I love Internet radio, everything we listen to can be monitored. Shortwave listening is still exciting, for the thrill is in the chase. I hope it will continue for some time. Thank you.
Hi and thank you for your comment! I completely agree with you.