US President Donald Trump on the weekend signed an govt order chopping funding to Voice of America. Based in 1942, VoA – whose future is now unsure – makes use of shortwave radio to broadcast present affairs programming to tens of millions of listeners internationally.
Shortwave radio – the place the wavelengths of the sign being broadcast are between 10m and 80m – was an essential expertise between the Nineteen Sixties and the Nineteen Nineties. Nonetheless, its significance diminished as digital media platforms, particularly the web, turned ubiquitous.
Shortwave radio’s significance was largely because of its means to be broadcast over extraordinarily lengthy distances. Indicators bounce off charged particles within the ionosphere, permitting them to journey to the far aspect of the planet with out the necessity for tons of of transmitters. For this reason shortwave broadcasts have performed an essential position within the dissemination of data throughout wartime.
A rebirth of the expertise could now be happening – with a digital twist.
“In South Africa, we’ve by no means used shortwave although it provides you the flexibility to transmit over lengthy distances,” mentioned Mark Willams, a broadcasting business veteran and presenter at LM Radio. No native broadcasters used shortwave, however that didn’t cease South Africans from tuning in to worldwide broadcasts, together with VoA, the BBC World Service and Radio France Internationale.
“Shortwave (and medium wave) radio is pricey to transmit, and the expertise took a again seat to FM due to FM’s superior high quality. Later, new broadcast media such because the web additionally took priority.”
Shortwave radio indicators (3-30MHz) are extremely vulnerable to interference from energy adapters, fluorescent or LED mild sources, web modems, routers and computer systems. The upper frequencies (88-108MHz) used for FM radio don’t decide up a lot of this interference.
Antiquated
In accordance with Williams, South Africa’s FM transmission infrastructure is nicely developed, with sign distribution towers throughout the nation. However these broadcasts are based mostly on antiquated analogue expertise. Though this setup was state-of-the-art many years in the past, South Africa has fallen behind as the remainder of the world moved on to digital radio.
The key price issue for analogue broadcasting is that the frequencies used to transmit FM channels solely journey round 60km, which means many extra broadcast towers are wanted, costing cash to deploy and keep. The towers should even have line of sight of one another, which means they have to be grouped collectively, with larger density required in hilly territory equivalent to in Kwa-Zulu Natal.
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Shortwave transmissions, however, permit for towers to be fewer and additional between. When digitised, in addition they required far much less energy to propagate.
This the place shortwave broadcasting is about to make one thing of a comeback, in keeping with Williams. Developments in broadcasting expertise have made it attainable to “refarm” the spectrum within the shortwave bands. Digital shortwave radio has some great benefits of its analogue predecessor, equivalent to long-distance sign propagation and low energy consumption, with out its drawbacks.
Digital shortwave radio is often known as Digital Radio Mondiale (DRM), a which is designed to work throughout the bands presently used for analogue radio broadcasting, together with shortwave.
DRM indicators are much less vulnerable to interference and provide extra channels for a similar quantity of bandwidth, which means three channels can exist the place just one may earlier than, however with stereo sound high quality.
There may be one other normal, known as DRM+, that makes use of FM frequencies – and different, related frequencies – for digital broadcasts.
DRM is just not the one digital radio broadcasting normal round. DAB, or Digital Audio Broadcasting, is competitor to DRM that has been deployed throughout a lot of Europe in addition to Australia. Practically 30 European international locations have DAB or DAB+ radio broadcasts. Like DRM, DAB permits extra stations to be broadcast utilizing the identical bandwidth as analogue broadcasts.
One of many drawbacks of migrating to digital radio, whether or not utilizing the DRM or DAB requirements, is that listeners should purchase radios that may decode the digital indicators. In accordance with Williams, that is already occurring in different components of the world like India the place DRM adoption is on the rise. He mentioned automobile manufactures are actually transport DRM-capable automobiles into India. Equipment like USB sticks and different adapters that add DRM performance to conventional radios are additionally accessible.
Learn: 100 years of radio in South Africa – and nonetheless going sturdy
“For Africa, DRM is the reply. Now we have massive areas to cowl the place there are small inhabitants teams in these areas, and DRM is cheaper. Radio expertise in South Africa hasn’t modified all that a lot within the final 30 years. Radio has been caught in a rut and frequencies are restricted, however that isn’t the case anymore, there are many frequencies and plenty of channels accessible,” mentioned Williams. — (c) 2025 NewsCentral Media
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