Hello friends,
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 in Italy.
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, 26-27 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 radiogram@verizon.net
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
Shortwave Radiogram Transmission Schedule
UTC Day UTC Time Frequency Transmitter
Saturday 0330-0400 UTC 9265 kHz WINB Pennsylvania
Saturday 1400-1430 UTC 9400 kHz Space Line Bulgaria
Saturday 1830-1900 UTC 9265 kHz WINB Pennsylvania
Sunday 0800-0830 UTC 5850 kHz 7730 kHz WRMI Florida
Sunday 2330-2400 UTC 7780 kHz WRMI Florida
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 x@xdv.me.
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: themightykbc@gmail.com . See also http://www.kbcradio.eu/ and https://www.facebook.com/TheMightyKbc/.
Thanks for your reception reports!
(Kim Andrew Elliott, KD9XB/Producer and Presenter)
Shortwave Radiogram
Reporting on international broadcasting at https://twitter.com/kaedotcom
