Saturday, August 31, 2013
VOA Radiogram programming
VOA Radiogram Program 24 this weekend, 30 August and 1 September 2013, will be rather complex.
Most VOA Radiogram listeners have had success using the RSID (Reed Solomon Identification) to automatically change modes. The RSID is the brief signal that occurs at the beginning of digital mode transmissions. One exception to this success is the RSID for MFSK64, which is not decoded on some listeners' software.
In an attempt to improve RSID performance, I have produced this weekend's VOA Radiogram using Fldigi 3.21.74AB. If you download, install, and use this "alpha" version of Fldigi from http://www.w1hkj.com/alpha/fldigi/v3.21/, we may have better luck with the RSIDs.
Please keep your previous version of Fldigi, at least for now, in case 3.21.74AB does not work well on your PC.
If you can't, or prefer not to, install 3.21.74AB, I will provide time for you to switch manually to MFSK64 and MFSK128.
In addition to the RSID experiments, VOA Radiogram will also transmit sample text in Vietnamese and Russian. Vietnamese has all sorts of diacritics, and Russian uses a Cyrillic alphabet, so this will be a real workout. You will need to use the UTF-8 character set. In Fldigi, UTF-8 can be selected in a menu located somewhere in Configure > Colors & Fonts, depending on your version.
This weekend's VOA Radiogram will also contain two transmissions in Flmsg format. The first will be a VOA News story similar to those transmitted during past weekends. The second will be a Base64-encoded VOA logo transmitted in MFSK128. Because of the speed of MFSK128, I'm expecting a fairly high failure rate. Worth a try, though.
Please close and restart Fldigi between VOA Radiogram broadcasts this weekend. This is because letters with accents often do not display correctly, i.e. UTF-8 no longer works, after an Flmsg item is received.
Here is the lineup for VOA Radiogram, 30 August/September 1 2013:
2:55 MFSK16: Program preview
3:10 MFSK32: Vietnamese and Russian text samples
2:58 MFSK32: Discussion of RSIDs
1:50 MFSK64/Flmsg: VOA News re dung beetles*
:56 MFSK32: Image of dung beetle
3:07 MFSK128/Flmsg/Base64: VOA blue logo*
2:16 MFSK64: VOA News re China hack attack
2:38 MFSK32: VOA Khmer radio photo contest
2:31 MFSK32: Image of submitted radio photo
1:10 MFSK16: Closing announcements
:15 Surprise mode of the week
*To make Flmsg work with Fldigi, in Fldigi: Configure > Misc > NBEMS, under Reception of flmsg files, check both boxes, and under that indicate where your Flmsg.exe file is located.
VOA Radiogram transmission schedule
(all days and times UTC):
Sun 0230-0300 5745 kHz
Sun 1300-1330 6095 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina.
Please send reception reports to firstname.lastname@example.org
Audio samples of difficult reception that nevertheless results in a successful text decode are especially helpful.
I will start today to respond to your emails from last weekend.
Kim Andrew Elliott
Producer and Presenter