VOA Radiogram is a Voice of America program experimenting with digital text and images via shortwave broadcasting. It is produced and presented by Dr. Kim Andrew Elliott.
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Experimenting with web pages via shortwave
VOA Radiogram during the weekend of 23-24 July 2016 included the transmission of an html-formatted VOA News story using the file transfer form of Flmsg, an add-on to the Fldigi software.
Many listeners reported a successful decode, resulting in a perfect looking news story, complete with headlines and hyperlinks. See the example below received by Lorne in New Zealand (Saturday 0930-1000 UTC on 5745 kHz). The photo was transferred to the listeners’ computers via the Internet. This may seem like cheating, because one of the main purposes of the VOA Radiogram project is to find ways to provide information when or where the Internet is not available, or restricted. But it was an interesting experiment with the hybrid use of shortwave and the Internet.
Several listeners reported a failure to receive the html file. The Flmsg file transfer form compresses files using base64. If even one character of that compressed file is lost in transmission (not unusual on shortwave!) , the checksum fails, and the html file cannot be decoded.
This weekend (30-31July) on VOA Radiogram, we will cheat again. The html-formatted VOA News story will include a photo and a video, both transferred to the listeners’ computers via the Internet.
This time, we will Flwrap, another Fldigi add-on program. Flwrap can be downloaded from https://sourceforge.net/projects/fldigi/files/flwrap/ . The Flmsg manual can be downloaded or is available here: http://www.w1hkj.com/Flwrap/ .
When the Flwrap VOA News story is finished transmitting, in Fldigi: File > Folders > NBEMS files > WRAP (folder) > recv (folder): drag the most recent .wrap file to the right window of Flwrap. If there is no checksum error, the wrap file will appear as VOA_Purple_270716.html in the same folder where the .wrap file was found.
If there is a checksum error, or Flwrap otherwise does not work, or if you do not have Flwrap installed, copy the content in the Fldigi receive pane from <html> through </html> (including the <html> and </html>, paste it to a text editor (like Notepad), save it as an .html file, then open the file in a web browser.
The html-formatted VOA News story as received by Lorne in New Zealand:
