Friday, May 17, 2013

Big Weekend for Digital SWBC Trials

VOA Radiogram:

More SSTV on VOA Radiogram May 18 and 19

On VOA Radiogram for the weekend on 18 and 19 May, we will continue to experiment with images. In fact, we will transmit the same picture three ways: in two SSTV modes and then as an MFSK32 image. Bring something to read, or an electronics project, because these picture transmissions will take 4 to 5 minutes each.

To decode the SSTV modes, several software programs are available. They include the RX-SSTV (receive only) from , MMSSTV from , and Digital Master 780, part of the Ham Radio Deluxe suite, from .

Before the images will be two VOA news stories in MFSK32 text, with the usual center audio frequency of 1500 Hz. The second story is in French, as we continue to determine if accented letters appear correctly on your display.

To view accented characters in Fldigi: Configure > Colors & Fonts > next to Select Char Set, select UTF-8. To keep your selection of UTF-8, under Configuration, click Save Config.  

Here is the lineup for VOA Radiogram the weekend on 18 and 19 May:

2:55        MFSK16 Program preview
1:59        MFSK32 VOA News in English
4:03        MFSK32 VOA News in French
1:07        MFSK16 Intro to SSTV transmissions
4:31        Scottie DX SSTV
 :10        Tone (to give you time to save your Scottie DX image)
5:08        Pasokon P5 SSTV
 :25        MFSK16 intro to MFSK32 image
4:07        MFSK32 image
1:10        MFSK16 closing announcements
1:22        Surprise mode of the week (mixes somewhat with the closing music)      
On VOA Radiogram during the weekend of 25-26 May, we will experiment with the Easypal digital SSTV mode, comparing it to MFSK32. Please download Easypal from . Easypal images are transmitted by radio amateurs on 14233 kHz.

VOA Radiogram transmission schedule
(all days and times UTC)

Sat 1600-1630 17860 kHz
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.

Pasokon P5 is an old mode.  I have no way of determining if it's one of MMSSTV's several undocumented modes.  [UPDATE 5/18: MMSSTV does do it, and it works well.]   -Hugh

The Mighty KBC

More Hell this weekend on The Mighty KBC

The Mighty KBC will transmit the Hell 80 mode at about 0133 UTC on Sunday 19 May (9:33 pm EDT Saturday), centered on 1500 Hz. This is during its North America broadcast Sunday at 0000-0200 UTC on 9925 kHz via Nauen, Germany.

At just before 0200 UTC, images in MFSK32 will be centered on 1000 and 2000 Hz.  

Hell is short for Hellschreiber, "Shiny Writing," an old CW based mode which synchronously prints letters onto paper tape or its various computer display emulations. Since darkness changes with signal strength, it's a "fuzzy" mode like analog fax.  This makes it possible to read the large double print even on sub-optimal channels. -Hugh

 Radio Australia:

Radio Australia digital text and image May 18 and 19

For the first time, Radio Australia will broadcast digital text and images. This will be Saturday 18 May and Sunday 19 May 2013.

UTC               Frequency (kHz)   Target

0830-0835      7410 & 11945        south-west Pacific

1230-1235      9580 & 12095 12065       south Pacific

As is characteristic of shortwave, reception outside the nominal target areas is likely.

Each five-minute broadcast will include:

  :34 RA tuning signal (still Waltzing Matilda?)
  :05 Tone 1500 Hz
1:42 MFSK16 text
1:42 MFSK32 text
  :55 MFSK32 image

All modes are centered on 1500 Hz

The Radio Australia digital transmissions can be received on any shortwave, even if it does not have single sideband capability. Patch audio from the radio to a personal computer, and use software to decode the modes. For more information, see how to decode the modes.