Last weekend was our second week of Shortwave Radiogram transmitted by
DRM (Digital Radio Mondiale) from WINB in Pennsylvania. I was able to
receive almost the entire half hour, and all of the images, using an SDR
DRM has its own methods for transmitting text and images, with which I
have little experience. On Shortwave Radiogram, we are just placing MFSK
on the audio that is decoded from a DRM signal – the same audio used
for voice and music broadcasts on WINB. The disadvantage of this is that
DRM is fussier than analog broadcasting, and the decode may fail in
conditions where an analog shortwave broadcast is usable, albeit with
some noise and fading accompanying the audio.
Is there any advantage to using DRM to transmit the digital text modes?
Possibly. The DRM C and D modes are designed to survive difficult
(typical!) shortwave conditions. But they produce telephone grade audio.
Telephone grade audio should be no problem for the digital modes.There
would be sufficient bandwidth to transmit modes that produce text at
3000 words per minute, or more. And with the background noise eliminated
by DRM, MFSK and SSTV images should be perfectly crisp. I look forward
to the possibility of future experiments with DRM.
Videos of last weekend’s Shortwave Radiogram (program 83) are provided by Scott in Ontario (Friday 2030 UTC), Ralf in Germany (Saturday 1400-1430 UTC), and 2010 DFS in Japan (Sunday 0800 UTC). The audio archive is maintained by Mark in the UK. Analysis is prepared by Roger in Germany,
This weekend, our usual MFSK32 and MFSK64, with nine images. The show will include the sixth and final image in the Tecsun Radios Australia decoding competition.
Here is the lineup for Shortwave Radiogram, program 84, 25-27 January 2019, in MFSK modes as noted:
1:48 MFSK32: Program preview
2:56 RFE/RL’s resumes its Bulgarian service*
(includes an excerpt of Bulgarian text)
8:21 MFSK64: Europe considers lunar mining mission*
12:12 This week’s images*
23:12 Tecsun Radios Australia decoding competition*
27:52 MFSK32: Closing announcements
* with image(s)
Please send reception reports to email@example.com
And visit http://swradiogram.net
Twitter: @SWRadiogram or https://twitter.com/swradiogram (visit during the weekend to see listeners’ results)
Facebook group: https://www.facebook.com/groups/567099476753304
Slow Scan Radio transmits SSTV images and text modes
Saturdays at 1300-1330 UTC on 6070 kHz and 7440 kHz via Channel 292 in
Germany – according to the latest schedule information I have. The
website is http://www.slowscanradio.com. Reception reports to firstname.lastname@example.org.
The Mighty KBC transmits to Europe Saturdays at
1300-1400 UTC on 11600 kHz from Bulgaria, with the minute of MFSK at
about 1330 UTC (if you are outside of Europe, listen via
websdr.ewi.utwente.nl:8901/ ). And to North America Sundays at 0000-0200
UTC (Saturday 7-9 pm EST) on 5960 kHz, via Germany. The minute of MFSK is at about 0130 UTC. Reports to Eric: email@example.com . See also http://www.kbcradio.eu/ and https://www.facebook.com/TheMightyKbc/.
Gough Lui in Australia decoded these images, Saturday 0330-0400 UTC,
9265 kHz from WINB Pennsylvania, use five disparate receivers …
Chris in New Zealand decoded these images 0330-0400 on 9265 kHz from
WINB Pennsylvania. In this broadcast, Jeff White’s voice was “totally
lost in the static” but the MFSK64 text (240 wpm) had only a small
number of errors …