Friday, March 27, 2015

Important Experimental 5-mode VOA Radiogram for March 28-29

VOA Radiogram is having an important test session this week.  Please read these essential instructions if you wish to participate in this test.

From Kim Andrew Elliott:


Hello friends,

For this weekend's VOA Radiogram, please download Fldigi 3.22.06 from http://w1hkj.com/download.html.

We will try two of the new 8PSK modes with forward error correction (FEC). These are available in 3.22.06. The FEC built into 8PSK125F and 8PSK250F might help these modes survive the rigors of shortwave, despite their fast speed.

Fldigi 3.22.06 also restores the ability to display UTF-8 characters [broken in 3.22.05 -Hugh], although this weekend's program contains no non-Latin characters or exotic punctuation marks.

This weekend's program (program 104) will transmit the same 724-word Reuters news story about social media in Africa in five different modes, each increasing in speed, until MFSK32 resumes to close the show ...

 2:53 MFSK32 (120 wpm)*
12:18 MFSK64 (250 wpm)*
18:05 8PSK125F (317 wpm)
20:55 MFSK128 (480 wpm)*
25:17 8PSK250F (635 wpm)
26:51 MFSK32: Closing announcements
27:33 MFSK32: Bonus image of solar eclipse

* with image

It is likely that decoding errors will be seen as the modes increase in speed. Nevertheless, please stay tuned until the closing announcements and image in MFSK32.

In Fldigi: Configure > Modems > PSK: At the bottom of this menu under "8 psk", leave the Pilot tone box unchecked, which is the default. We will try the pilot tone with 8PSK during the weekend of April 4-5.

Please send reception reports to radiogram@voanews.com.

VOA Radiogram transmission schedule
(all days and times UTC):
Sat 0930-1000 5910 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.

* This will change to 5745 kHz beginning 4 April 2015.

The Mighty KBC will transmit a minute of MFSK64 Saturday at about 1230 UTC on 6095 kHz and Sunday at about 0130 UTC on 7375 kHz. Both frequencies are via Germany. The last KBC Saturday broadcast on 6095 kHz will be 28 March. KBC will continue Sundays at 0900-1600 UTC on 6095 kHz.

AndFlmsg. If you have an Android device, please try the free beta Android app AndFlmsg from http://www.w1hkj.com/vk2eta/. Although AndFlmsg is designed for Flmsg forms, it also decodes plain text (non-Flmsg) content. Swipe AndFlmsg until you reach the modem screen, the one with the W.Fall On/Off button bottom right. Acoustic coupling -- radio speaker near the Android device's built-in mic -- usually works well. [Works great here. Everything but the images. - Hugh]

Thank you for your reception reports from last weekend. I will compile the MFSK image gallery and respond to your reports as soon as I can.

As of the end of March 2015, VOA Radiogram has been on the air two years. We are still learning new things about text and images via shortwave, and software is being developed. Thanks for your support.

Kim

Kim Andrew Elliott
Producer and Presenter
VOA Radiogram
voaradiogram.net