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MFSK32 on The Mighty KBC, 7395 kHz via Germany, succeeds even though it is co-channel with the Radio Romania International interval signal, 0158 UTC, 13 December 2015. Interestingly, the RRI signal disappears under my local noise floor when the transmitter in Germany signs off a few seconds after 0200 UTC.
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VOA Radiogram, 12-13 December 2015: bright spots
See the previous post about this weekend’s experiment with co-channel interference.
Here is the lineup for VOA Radiogram, program 141, 12-13 December 2015, all in MFSK32:
1:32 Program preview
2:47 Planet Ceres’ bright spots explained*
8:21 Estonian underwater robot*
16:55 Russia’s Dozhd TV under pressure*
22:10 Santa on 3916 kHz*
24:46 Closing announcements** with image
Please send reception reports to radiogram@voanews.com.
VOA Radiogram transmission schedule
(all days and times UTC):
Sat 0930-1000 5865 kHz
Sat 1600-1630 17580 kHz
Sun 0230-0300 5745 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina.If you have an Android device, the TIVAR decoding app is available here: http://sourceforge.net/projects/fldigi/files/AndFlmsg/TIVAR/ . For PCs, Fldigi is available here: http://sourceforge.net/projects/fldigi/files/ . See w1hkj.com for more information.
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Fun with QR codes
VOA Radiogram, program 140, 5-6 December 2015, experimented with the transmission of QR codes as MFSK images and as UTF-8 block elements.
Here is the QR code as an MFSK32 image, received by Gough in Australia, about 14000 km from the North Carolina transmitter, 5 December during the 0930-1000 UTC transmission on 5865 kHz …
The same QR code transmitted as UTF-8 block elements in MFSK32 (120 wpm) was received much more clearly in Australia. It took advantage of the error correction included in MFSK32 text. …
The QR code transmitted as UTF-8 block elements in MFSK64 (240 wpm) did not survive the path to Australia …
But, from several locations in Europe and North America, there were many examples of the MFSK64 block elements decoding perfectly. For example, this one from Jeff in Texas (5 December, 1600-1630 UTC, 17580 kHz) …
Because of the uneven lines in the example above, the QR code does not decode successfully. It needs a monospace font, either in the Fldigi software, or in whatever text editor or word processor it is pasted to …
In the above example, even lines have been accomplished because of the monospace font. But the text editor shows thin horizontal white space between the lines, making the QR code difficult to decode. So the same QR code is pasted to plain old MS Notepad …
Notepad has a monospace font by default, and the horizontal white space is absent.
If you haven’t decoded the QR code yet, it’s the URL of the VOA Radiogram website …
voaradiogram.net
Bottom line, plain text is simpler and faster than the QR codes. But the QR code experiment was fun.
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A co-channel experiment on 7395 kHz
This weekend, the minute of MFSK32 on The Mighty KBC moves to 0158 UTC (Saturday 8:58 pm EST in North America).
This is at the end of KBC’s broadcast to North America UTC Saturday at 2300 to Sunday at 0200 UTC on 7395 kHz, via Germany.
At 0158 UTC, Radio Romania International begins transmitting the interval signal for its French-language broadcast starting at 0200 UTC, on the same 7395 kHz.
The digital mode at 0158 UTC is an experiment to see if the MFSK32 text and image can be decoded despite the RRI interval signal on the same frequency.
Reception reports for KBC to Eric: themightykbc (at) gmail.com
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VOA Radiogram, 5-6 December 2015: UTF-8 QR codes and Xenokeryx amidalae
This weekend on VOA Radiogram, we will conduct one more (for now) QR code experiments. The VOA Radiogram URL will be transmitted as 1) plain text, 2) as a QR code via MFSK32 image, 3) as UTF-8 block elements – those things that look like this:
A QR code transmitted this way will benefit from the error correction inherent in any MFSK text transmission. You will need the UTF-8 character set (Fldigi: Configure > Colors & Fonts > Rx/Tx Character set).
The transmission of the QR code as UTF-8 in MFSK32 is slow, so after the MFSK32, the QR code will be sent in MFSK64 for increased speed.
Here is the lineup for VOA Radiogram, program 140, 5-6 December 2015, all in MFSK32 except where noted:
1:31 Program preview
2:58 Experiments with QR codes **
7:13 MFSK64: QR code ***
8:31 MFSK32: Court ruling on Turkey’s blocking of YouTube *
12:44 Solar-powered plane will resume flight *
18:53 Prehistoric beast looks like Star Wars queen *
24:55 Closing announcements ****
* With image
** The QR codes using block element require the UTF-8 character set. In Fldigi: Configure > Colors & Fonts > Rx/Tx Character set - set to UTF-8.
*** After the MFSK64 RSID, there will be 10 seconds of silence in case the mode must be changed manually.
**** After the closing announcement, a custom QR code made by Robert in Ontario.
Please send reception reports to radiogram@voanews.com .
VOA Radiogram transmission schedule
(all days and times UTC):
Sat 0930-1000 5865 kHz
Sat 1600-1630 17580 kHz
Sun 0230-0300 5745 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina.
The Mighty KBC will transmit a minute of MFSK32 Sunday at 0130 UTC (Saturday 8:30 pm EST) on 7395 kHz, via Germany. Reports for this KBC reception to Eric: themightykbc (at) gmail.com .
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VOA Radiogram, 28-29 November 2015: Türk and more QR codes
This weekend on VOA Radiogram, we will transmit two more QR codes, smaller than the ones sent last week. Also, a VOA Turkish news story, so have your Fldigi set for UTF-8.Here is the lineup for VOA Radiogram, program 139, 28-29 November 2015, all in MFSK32 except where noted:
1:31 Program preview
3:10 New Shepard reusable rocket lands after launch*
7:55 Lasers used to cool water*
14:09 El Niño Brings Unexpected Fish to California*
19:30 News item from VOA Turkish Service**
22:45 Closing announcements*
26:05 Olivia 64-2000: Transmission schedule
* with image
** Requires UTF-8 for proper display of diacritics. In Fldigi: Configure > Colors &Fonts > Rx/Tx Character set to UTF-8Please send reception reports to radiogram@voanews.com.
VOA Radiogram transmission schedule
(all days and times UTC):
Sat 0930-1000 5865 kHz
Sat 1600-1630 17580 kHz
Sun 0230-0300 5745 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina.The Mighty KBC will transmit a minute of MFSK32 Sunday at 0130 UTC (Saturday 8:30 pm EST) on 7395 kHz, via Germany. Reports for this KBC reception to Eric: themightykbc@gmail.com .
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QR codes, transmitted via shortwave, then scanned
VOA Radiogram, program 138, the weekend of 21-22 November 2015, experimented with the transmission of QR codes via shortwave. Can the QR codes be successfully scanned after enduring the rigors of shortwave propagation?
The answer is yes, to a point.
An example of success are these QR codes received and decoded by Chris in New Zealand, about 14000 km from the North Carolina transmitter, 22 November at 1930-2000 UTC, 15670 kHz.
The first QR code is a link to a VOA News story …
The second QR code is the VOA Radiogram transmission schedule …
Frank in the Netherlands had a fuzzy decode of the 15670 kHz transmission, but I am able to scan this one using my Asus tablet …
These images decoded by Alan in England, also from the 15670 kHz transmission, are sufficiently fuzzy that I usually cannot scan them successfully, but you might have better luck …
A YouTube video of the Saturday, 21 November, broadcast at 1600-1630 UTC on 17580 kHz, provided by Tim in Colorado, shows the QR codes as received and “painted” using the Fldigi software. The QR code images begin at 17:45 and 25:45 into the video: https://youtu.be/QFYCq3-mmhU
Is there any advantage to transmitting QR codes? In terms and speed and efficiency, perhaps not. The URLs and small text messages are more likely to survive shortwave as plain text, which in MFSK enjoys the benefit of forward error correction. MFSK images are more vulnerable.
It is, however, possible to transmit a QR code as UTF-8 characters, thus taking the advantage of the error correction in text transmission. Such experiments will take place in future editions of VOA Radiogram.
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Program 138 on 15670 kHz: Images tell the story of very variable propagation
Reception of VOA Radiogram, program 138, on 22 November 2015, 1930-2000 UTC, on 15670 kHz, suffered from very poor trans-Atlantic propagation. One example is this image of the exoplanet Kepler-438b next to its sun, as decoded by Merkouris in Greece …
Alan in England had somewhat better results …
Philippe-Jérôme in France was the one European listener who experienced good reception during this broadcast …
In eastern North America, reception was also difficult, per this example from Al in Florida …
This were better in Texas, given this decode by Jeff …
But the real surprise was good reception of the Sunday 1930-2000 broadcast by Chris in New Zealand, about 14000 km from the North Carolina transmitter …
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Frank in Perth, Western Australia, sent this collection of text and images decoded 21 November 2015, 0930-1000, on 5865 kHz, via North Carolina, about 18000 km away. This transmission uses a dipole antenna nominally directed to the Caribbean. The MFSK32 text shows many errors, but the very robust Olivia 64-2000 (bottom right) was 100%. The images were fuzzy but recognizable. The QR code was too fuzzy to decode when scanned.
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Oscar in Italy provided this video of the VOA Radiogram experiment with the simultaneous transmission of text and an image. The text was centered on 1500 Hz, and the image on 2200 Hz. This was during the 1600-1630 UTC broadcast, 21 November 2015, on 17580 kHz. The transmitter is in North Carolina, and the receiver in Milan.