Shortwave radio, the original and most crucial form of radio communication in our history, and dropped by many countries 20 years ago, is set for a resurgence!
Used heavily during the Cold War, shortwave was vital for communications in isolated areas.
After the war, listenership dwindled and as the equipment aged and the energy bills continued to accrue, one of the first in line for budget cuts was shortwave, with no importance placed on replacing it.
Not unlike the song, “Video Killed the Radio Star”, many say that satellites and the internet killed shortwave radio.
Really it is a combination of technology and content delivered directly to the savvy FM listener and streamed to the cell phone obsessed user generally at a reduced cost compared to shortwave.
As Shortwave dwindled, radio began being broadcast in FM and DAB modes to radios, devices, and laptops, with thousands of listening options.
Many new broadcasters began piggybacking on the local popular informative radio stations.
This new technology, however, in many countries is not without its issues. At first, it might appear that these are cheaper and more modern options, but slow buffering times, multiplexed DAB+, excessive and expensive cost of data in many countries, as well as a listener’s preference for anonymity has seen a return to shortwave.
As mentioned in previous articles the emerging ability to transmit shortwave radio digitally using DRM ( Digital Radio Mondiale) has seen a resurgence in the use of shortwave due to its wide coverage and heavily reduced cost.
Specifically China has opted to use DRM Shortwave to provide full coverage to the areas between the large cities.
China National Radio broadcasts from five upgraded sites 80 hours a day with seven to eight transmitters sending shortwave DRM to most areas of North China, East China, South China and Southwest China. Russia is also airing DRM in shortwave over huge areas of Siberia.
India is now looking to increase its three DRM shortwave transmitters for further national and international reach.
Several CRN transmitters beam enormous DRM signals into our part of the world daily.
Indonesia and Brazil are also said to have expressed interest in adapting their shortwave analog over to DRM for greater coverage.
As mentioned previously Vanuatu, has recently opted for DRM shortwave to save lives in disaster situations by using its integrated emergency warning capability, and a site in the United States has recently started broadcasting in DRM the popular Radio Marti programs toward central and Latin America.
As many areas of the world are re-discovering the value of shortwave we may see the resurgence of shortwave being replaced by its new digital form.
Are you interested in listening to Shortwave radio? Imagine picking up and decoding radio stations from remote areas of the world? Re connect with the world during this time of isolation.
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Russia is considering the re-introduction of shortwave radio using DRM (Digital Radio Mondiale), a technology which is designed to cover large areas at modest operating cost.
Prior to the 2000’s, shortwave was broadcast in Chukotka for communications across the far northeastern region of Russia and the Northern Sea but was gradually discontinued as funding became more difficult to obtain.
Due to the unique capabilities of shortwave transmissions coupled with the new capabilities of DRM, an audience size of a few thousand spread over a vast area could be best serviced by shortwave again.
Transmitting shortwave digitally offers the advantage of long-distance coverage and a higher fidelity signal. Text information such as news and weather can also be embedded in the signal and decoded at the receiver. Recent studies show that DRM is just as reliable as analog shortwave over this distance via single-hop transmission. An added benefit of DRM transmissions is they use a quarter of the power that analog transmissions.
This new shortwave service is named Radio Purga (“Radio Blizzard”), a joint project between the government in Chukotka and the Far Eastern Regional Center and the government in Chukotka
The target audience includes people in the Northern Sea including mariners, miners, geologists, hunters, and nomadic reindeer herders. All of these groups would benefit from both news and weather as well as traditional entertainment programming.
A range of test transmissions commenced in August 2019 via different DRM modes and bandwidths to trial “hardware setup and determine signal acceptability,” with the goal of covering over 95% of the area. Programming consists of a music loop and interestingly has been heard as far away as the United States.
Currently the broadcaster is still carrying out transmission tests on 5935, 6025, 11860 and 15325Khz.
Radio Purga’s regular programming is expected to begin sometime in the next few months. One of shortwave’s finest capabilities is to communicate to hard-to-reach locations. Radio Purga’s audience is spread over a remote and vastly spread region.
Resuming shortwave via DRM will provide the population with a critical communication source in both audio and text.
Do you enjoy listening to shortwave and have noticed the frequencies used by your favourite broadcaster change twice a year? Interestingly there is a scientific reason behind this.
Shortwave travels long distances because of its unique way of propagating. The transmission is beamed upwards towards the sky where it is reflected back down to earth spanning a huge distance between the two points. In good conditions a single transmitter is able to reach millions of listeners around the world.
This is what makes shortwave unique and incredibly effective, especially to remote audiences as well as to areas where news and information is highly controlled.
As a general rule, higher frequencies (SW) work best during daylight hours and summer time while lower frequencies (MW) work better in darkness – before dawn and during the long winter evenings.
This same frequency can not be used all year round because as the seasons change the number of daylight hours at any location can directly affect the optimum frequency band. This is because the energy from the Sun required to ionise reflective layers in the upper atmosphere is directly impacted by the sunlight hours available. So seasonal changes causing shorter sunlight hours will affect daily propagation of a higher frequency, and so a lower frequency will need to be chosen to provide similar coverage during the period of shorter days.
The High Frequency Coordination Committee (HFCC, under the ITU International Telecommunications Union) is the body that has the responsibility to decide when to change shortwave frequencies.They must coordinate these changes with all the major shortwave broadcasters around the World.
To ensure the optimal transmission conditions the HFCC recommend two seasonal frequency schedules – summer and winter – known as the ‘A’ and ‘B’ seasons.
The changeover between seasons is internationally agreed to occur on the last Sunday in March (start of ‘A’ season) and the last Sunday in October (start of ‘B’ season), which coincides with start and end of ‘Daylight Saving’ in many countries, where local time can change.
The changeover ‘A20’ season has just occurred on Sunday 29th March, and the frequencies agreed for all shortwave transmissions will continue until the beginning of the next season ‘B20’, on Sunday 25th October.