This weekend on VOA Radiogram, in addition to our usual MFSK32, we will conduct experiments with Olivia at different speeds.

In general, the Olivia modes are too slow for broadcasting. However, we should keep in mind that text via shortwave can be received unattended, for later retrieval, making speed less of an issue. Furthermore, the Olivia modes might be more capable of overcoming co-channel interference than our usual MFSK modes.

The speed of the Olivia modes increases as 1) bandwidth increases and 2) the number of tones decreases. However, as the number of tones decreases, the robustness of the mode, i.e. the ability to decode in difficult reception conditions, decreases.

On our shortwave broadcast channel, we will use the maximum 2000 Hz bandwidth. We will transmit about three minutes of content in each of Olivia 64-2000 (29 wpm), 32-2000 (48 wpm), 16-2000 (76 wpm), and 8-2000 (104 wpm). As the number of tones decreases, and the Olivia modes become faster, how much does performance deteriorate?  

There are RSIDs for each of these Olivia modes. If you change modes manually, you will have to use the Custom menu for the 32-, 16-, and 8-tone versions. Even if the signal is so bad that you can barely hear it, change the modes manually at the appointed time, and you might see the text. Because of latency in the Olivia modes, text will not begin to display until a few seconds after the tones begin.

Here is the lineup for VOA Radiogram, program 48, 1-2 March 2014:

1:34  MFSK32: Program preview

2:48  MFSK32: Introduction to Olivia experiment

4:35  Olivia 64-2000: Excerpt of VOA News story

8:29  Olivia 32-2000: Excerpt from same VOA News story

12:02  Olivia 16-2000: Excerpt from same VOA News story

15:17  Olivia 8-2000: Excerpt from same VOA News story

18:23  MFSK32: Hospital machinist, with image

26:07  MFSK32: Closing announcements

Please send reception reports to radiogram@voanews.com

VOA Radiogram transmission schedule

(all days and times UTC):

Sat 0930-1000 5745 kHz

Sat 1600-1630 17860 kHz

Sun 0230-0300 5745 kHz

Sun 1930-2000 15670 kHz

All via the Edward R. Murrow transmitting station in North Carolina.

Last weekend’s experiment with the simultaneous transmission of MFSK32 text and an MFSK64 image was fairly successful. We still need to determine the best combination of modes and audio frequencies for simultaneous text and image transmissions.

This weekend we will resume more conventional sequential text and image transmissions. MFSK32, MFSK64L, and MFSK64 will be used.

Here is the lineup for VOA Radiogram, 22-23 February 2014, program 47:

  1:40  MFSK32: Program preview
  2:55  MFSK32: Greetings to WinteRFest in Iowa, with images
  6:03  MFSK32: Winter SWL Fest forums, with image
  7:24  MFSK32: Lasers for space communication, with image
12:09  MFSK64L: Restrictions on Turkish media, with MFSK64 image
19:19  MFSK64: Independent bookstores in USA, with image
26:35  MFSK32: Closing announcements

Please send reception reports to radiogram@voanews.com

VOA Radiogram transmission schedule
(all days and times UTC)
Sat 0930-1000 5745 kHz
Sat 1600-1630 17860 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, with studios in the Netherlands but leased transmitters in Germany, will transmit a minute of MFSK64 Saturday at about 1230 UTC on 6095 kHz, and again Sunday at about 0130 UTC (Saturday evening 8:30 pm EST) on 7375 kHz. The 6095 kHz is usually not audible in North America except via this SDR receiver in the Netherlands: http://websdr.ewi.utwente.nl:8901/ . Please send reception reports to Eric at themightykbc@gmail.com.

The Winter SWL Fest will be 14-15 March 2014, near Philadelphia. I will be there to demonstrate VOA Radiogram and the decoding of text and images from shortwave broadcast. Information at swlfest.com.

VOA Radiogram the weekend of 15-16 February 2014 included the simultaneous transmission of text (MFSK32) and an image (MFSK64). There were also some Chinese characters.

Tim in Colorado has produced this YouTube video of his decoding of VOA Radiogram, 15 Feb, 1600-1630 UTC, 17860 kHz:

http://youtu.be/Ry_PpYGV2_A

(Other videos from the weekend may be added here.)

Roger in Germany has compiled this html document with all the text and images, plus some screenshots, from the the same broadcast:

http://www.rhci-online.de/VoA_Radiogram_2014-02-15.htm

VOA Radiogram during the weekend on 8-9 February 2014 included the simultaneous transmission of MFSK32 text and images. This can be observed in the following YouTube videos provided by listeners. In chronological order…

Steve in Nebraska, 8 Feb 2014, 0930-1000, 5745 kHz
youtu.be/v2SsjEo0__Q
 
Mark in the UK, excerpt of the same broadcast (audio is not the same as text and images on display):
youtu.be/7whTHCarB2g

Tim in Colorado, 8 Feb, 1600-1630 UTC, 17860 kHz:
youtu.be/VfBR6VwstDE
 
Steve in Nebraska, same broadcast, using Sony ICF-SW7600 receiver:
youtu.be/4C0kfP2HreQ

Steve again, same broadcast, using 1950s-era R392 military receiver:
youtu.be/Fz5x5pdQHVg

Piotr in the UK, 9 Feb 2014, excerpt of the broadcast at 0230-0300 UTC on 5745 kHz:

youtu.be/Pdn1V2L35sA  

Roger in Germany compiled all the text, images, and screenshots from the broadcast 8 Feb at 1600-1630 UTC:
www.rhci-online.de/VoA_Radiogram_2014-02-08.htm

Here is the QSL for VOA Radiogram, program 45, 8-9 Feb 2014:

On VOA Radiogram during the weekend of 15-16 February 2014 (program 46), we will try another simultaneous transmission of text and an image. This time it will be text in MFSK32 centered on 2000 Hz, and the image in MFSK64 centered on 1000 Hz.

Here is the procedure:

1) Have two instances of Fldigi running.

2) Turn on the RxID (green) on both instances of Fldigi.

3) After the mode changes to MFSK64, turn off the RxID on your
second instance of Fldigi.

Program 46 will also include Chinese characters, transmitted as MFSK32 and later (and faster) as MFSK64L.

Here is the lineup for VOA Radiogram, program 46, 15-16 February 2014:

  1:35  MFSK32: Program preview
  3:50  MFSK32/64: Press freedom index with simultaneous image*
10:49  MFSK32: Bing accused of censorship, with image
16:41  MFSK32: Hacking at Sochi Olympics, with image
22:09  MFSK32: Sample of VOA Chinese text**, with image
25:22  MFSK64L: Same sample of VOA Chinese text
27:28  MFSK32: Closing announcements

*Run two instances of Fldigi, starting with RxID on in both
instances. Test will be centered on 2000 Hz, the image on 1000
Hz.

**Use UTF-8 character set. In Fldigi: Configure > Colors & Fonts
> Rx/TX > Set top (white) box to UTF-8.

Please send reception reports to radiogram@voanews.com

VOA Radiogram transmission schedule
(all days and times UTC):
Sat 0930-1000 5745 kHz
Sat 1600-1630 17860 kHz
Sun 0230-0300 5745 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina

Last weekend’s experiment with the simultaneous transmission of MFSK32 text and images was mostly successful. We’ll try it again this weekend on VOA Radiogram.

The procedure will be the same. You can decode the two streams sequentially from your recording. Or you can run two instances of Fldigi, as follows:

1) In both instances of Fldigi, turn the RxID on (green).

2) An RSID for MFSK32 at 2100 Hz will be transmitted, moving both instances of Fldigi to an audio frequency near 2100 Hz.

3) On the second instance of Fldigi, turn the RxID off.

4) An RSID for MFSK32 at 1500 Hz will be transmitted, moving your first instance of Fldigi back to an audio frequency near 1500 Hz.

5) Test will be transmitted centered on 1500 Hz, and the images centered on 2100 Hz.

6) After the dual MFSK32 transmissions, you can turn off or minimize your second instance of Fldigi.

Here is the lineup for VOA Radiogram, program 45, 8-9 February 2014:

  1:30  MFSK32: Program preview
  4:06  MFSK32: Winter SWL Fest, with simultaneous image
  5:30  MFSK32: Graphene, with simultaneous image
10:05  MFSK32: Telescope
16:22  MFSK64: Image of telescope
18:24  MFSK64: St. Louis aviation, followed by image
23:52  MFSK64: Turkey Internet crackdown, followed by image
27:06  MFSK32: Closing announcements

Please send reception reports to radiogram@voanews.com

VOA Radiogram transmission schedule
(all days and times UTC)
Sat 0930-1000 5745 kHz
Sat 1600-1630 17860 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 again this weekend, via Germany, Saturday at about 1230 UTC on 6095 kHz, and Sunday at about 0130 UTC on 7375 kHz (8:30 pm EST – part of a broadcast from 7 to 9 pm EST). Eric enjoys receiving reception reports, so please send them to themightykbc@gmail.com. Website is kbcradio.eu.

The Winter SWL Fest will be March 14-15 in suburban Philadelphia. I plan to be there to demonstrate the decoding of text and images from VOA Radiogram. More information at swlfest.com. Register in advance or walk in.

YouTube videos of VOA Radiogram, program 44, the weekend of 1-2 February 2014, show the decoding of the simultaneous MFSK32 text and image transmission.

Lorenzo, near Rome, produced this video of the broadcast on 1 February at 1600 UTC on 17860 kHz:

youtu.be/JxtRP9MhPLU

Tim in Colorado provided this video of reception UTC 2 February at 0230 on 5745 kHz:

youtu.be/klBkpHUum0w

Oscar in Milan made this video of an excerpt from the same broadcast:

youtu.be/uWymJN-Z_8g

Marco, near Rome, produced this video from the broadcast on 2 February, 1930-2000 UTC, 15670 kHz:

youtu.be/PXuCyflnYbA

Roger in Germany compiled all the text and images, plus Fldigi screenshots, in this html document:

www.rhci-online.de/VoA_Radiogram_2014-02-01.htm