The Voice of America is set to launch a new communication service on shortwave radio with interesting implications for information flow in crisis situations or under repressive regimes.
Called Radiogram, the service uses digital encoding to transmit text and images via analog shortwave broadcasts. The transmissions themselves sound much like old dial-up modems (at root the technologies are identical, in that both involve the conversion of data to audio), but when decoded on an equipped receiver or computer the text and images appear.
Not a new concept, but it's the first instance of its deployment on shortwave. Amateur and pirate broadcasters use it regularly; for example, many shortwave pirates end their transmissions with slow-scan TV images.
The idea behind Radiogram is to facilitate the spread of vital information in areas of the world where communications are restricted. Shortwave provides massive range – and the technology works remarkably well even in conditions where reception of regular programs are degraded, including jamming.
The software needed to decode the transmissions remains to be consolidated and simplified for mass use, but that work is underway.
The Voice of America is currently producing a lengthy program to further explain and promote Radiogram, which will include sample transmissions. They hope to recruit shortwave listeners from around the world to decode the broadcast and report the results – a crowdsourced listening test of the new system.
This program will originate from the VOA's Edward R. Murrow Transmitting Station in Greenville, North Carolina with an airdate TBA. At present, test Radiogram broadcasts are taking place on Bulgarian shortwave station KBC, though they will be moving to a facility in Nauen, Germany next month. (Source: http://dymedia.net)
Freqs registered with HFCC effectjve March 1 2013 are:
5745 0230-0300
6095 1800-1830
15670 1600-1630
17860 1600-1630
The link above should read http://diymedia.net
ReplyDeleteI played with PSK31 and PSK63 years ago. It's mildly interesting and fiddly to configure. However, it does allow you to transmit information data/information over long distances without requiring high power, so this should be easy for VOA and others to accommodate into their existing transmissions.
What will be needed is software that can be accessible by listeners without significant technical knowledge. I'm quite curious to see what sort of delivery the code crunchers come up with.
You can try out all this stuff out (the VOA-used software) by downloading for either Linux, Windows or OSX at:
http://www.w1hkj.com/download.html
What will be more interesting is to see how VOA intends to use this facility - its purpose and implementation.
Rob VK3BVW