[A-DX] QSL: RFA Cantonese - DigitalText

[Roger]

http://www.rhci-online.de/files/RFA-Cantonese-Radiogram-QSL.jpg

betraf diese RFA-Ausstrahlungen:
http://www.rhci-online.de/VoA_Radiogram_2014-09-13.htm


Die Testausstrahlungen wurden beendet und werden nicht weitergeführt.
Kim Andrew Elliott schrieb dazu:


"........The *Radio Free Asia* transmissions of digital text via 
shortwave have ended and will not resume. I am surprised by this 
decision, because the RFA tests showed that in even in the face of 
deliberate Chinese co-channel interference, digital text provided a very 
successful decode.

Here is an example: RFA Cantonese as received in Hong Kong, 14 September 
2014, 2257 UTC, on 15390 kHz. The female voice is China National Radio. 
The male voice in the background in RFA Cantonese. The mix of CNR and 
RFA creates a generally inaudible mess. The Olivia 32-2000 mode 
penetrates the cacophony, resulting in successfully decoded text (try 
decoding it yourself)...

https://soundcloud.com/voaradiogram/rfa-cant-140914-2257-15390-hk

I initiated experiments with digital text via analog shortwave broadcast 
about two years ago to find a way to work around the blockage and 
censorship of Internet content. The VOA Radiogram experiments show that 
text and images can successfully be transmitted via shortwave: a useful 
capability when the Internet is blocked.

However, we can assume that if a country blocks Internet traffic, it 
will probably also jam shortwave transmissions. Text via shortwave must 
also have anti-jamming capabilities. Tests of digital text modes amid 
actual jamming are -- were -- essential to the VOA Radiogram concept. 
Now that VOA and RFA have both discontinued tests of text to China, 
experiments with Chinese jamming are no longer possible within the realm 
of US-government-funded international broadcasting...."




roger