Category Archives: Digital Modes

VOA Radiogram this weekend mixes bad noise with good noise

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VOARadioGram(Source: VOA Radiogram)

During the past weekend, we experimented with mixing music with MFSK text modes. Reducing the MFSK modes by 9 dB was not a problem if the signal level was good, but the MFSK text did break up for some listeners if reception conditions were marginal.

This weekend, 15 and 16 June, we will mix some actual noise taken from shortwave with MFSK text. After the noise begins, a VOA News story in MFSK16 will first be transmitted at full level, then reduced to -6 dB, then reduced to -12 dB. I will probably lose many of you when the level is reduced to -12 dB, but please stay tuned: the audio level will soon be restored.

Here is the lineup for VOA Radiogram, 15 and 16 June 2013:

  • 2:10 MFSK16: Program preview
  • 1:58 MFSK16: Introduction to noise experiment
  • 10:09 MFSK16: At -0 -6 -12 dB versus noise
  • :59 MFSK16: Image of VOA logo
  • :47 MFSK16: Introduction to MFSK32
  • :51 MFSK32: Image of VOA logo
  • 3:19 MFSK32: VOA News re Curiosity Rover on Mars MFSK32: VOA Radiogram logo
  • 2:40 EasyPal Image of the week
  • 1:10 MFSK16: Closing announcements
  • :20 Surprise mode of the week

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.

Please send reception reports to [email protected]

Radio Australia transmitting digital radiograms this weekend, June 8 – 9

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ABC-Radio-Australia

Most encouraging to see Radio Australia sending digital text over shortwave. Their 12:30 UTC broadcast should be easily heard in North America on 9,850 kHz:

(Source: VOA Radiograms)

Radio Australia will transmit digital text and an image during three special broadcasts the weekend of 8 and 9 June 2013.

The seven-minute broadcasts will consist of…

MFSK16 text
MFSK32 text
MFSK32 in Flmsg* format (creates Radio Australia logo in browser window)
MFSK32 image (ABC logo)

*Fldigi and Flmsg from www.w1hkj.com must be used together. In Fldigi, click Configure > Misc > NBEMS: Under Reception of flmsg files, check both boxes, and under that indicate where your Flmsg program file is located.

Transmission schedule

All dates/times are in UTC, all frequencies in kHz

Saturday/Sunday 8/9 June 2013

Nominal target areas are listed. Reception beyond these target areas is likely.

0850-0857 UTC

  •  7410 kHz (PNG & south-west Pacific)  
  • 11945 kHz (south Pacific, NZ, central America, Europe)

1230-1237 UTC

  •  6080 kHz (PNG, west Pacific, Philippines, Japan)
  •  9580 kHz (central Pacific, NAM)  
  • 12065 kHz (central Pacific, NAM)

2150-2157 UT C

  • 11695 kHz (south-east Asia, Europe) 
  • 21740 kHz (central Pacific, NAm) 

Each broadcast begins with with 40 seconds of Radio Australia interval signal (Waltzing Matilda).

VOA Radiogram features EasyPal digital images this weekend

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VOARadiogram(Source: VOA Radiogram)

During the past weekend, EasyPal digital images were received successfully throughout Europe and North America. You can see a gallery of some of the received images here:

voaradiogram.net/post/51385444401/voa-radiogram-easypal-images-received-100-or-0

Reviewing the advantages of EasyPal versus MFSK32:

EasyPal:

1) When received successfully, the picture is perfect.

2) Takes less time to transmit than MFSK32 and most SSTV images of the same size.

3) No problems with slant if soundcards are not calibrated.

MFSK32:

1) If the signal drops below a certain level, or if interference exceeds a certain level, no EasyPal image will be received at all. Under similar reception conditions, MFSK32, which uses an analog frequency shift keying system for images, will allow the an image to be seen, even if the quality is not perfect.

2) MFSK32 images allows images of different heights and widths, including small images which can be transmitted quickly. The gray tone MFSK32 image option allows even faster transmission.

3) MFSK32 images can be decoded by more than one software program under more than one operating system. There is only one EasyPal program, and it works only under the Windows operating system.

I welcome your comments and suggestions about the transmission of images via shortwave broadcast. Weighing all of the above factors, I am inclined to adopt MFSK32 as the primary image mode for VOA Radiogram. However, the EasyPal images are so impressive that I will continue to include some in future programs.

On VOA Radiogram for the weekend of 1 and 2 June 2013, we will continue to compare MFSK32 and EasyPal images. Here is the lineup for the program:

3:44    MFSK16: Program preview
3:17    MFSK32: VOA News story about Olympics wrestling
3:16    MFSK32: VOA News story about 2013 hurricane season
1:10    MFSK32: File image of Atlantic hurricane
2:53    MFSK32: VOA News story about colliding galaxies
1:04    MFSK32: Image of the colliding galaxies
1:21    MFSK32: Introduction to MFSK64 and EasyPal
1:30    MFSK64: Same VOA News story about colliding galaxies
:39     EasyPal text: Same VOA News story about galaxies
2:38    EasyPal image: Colliding galaxies
2:38    EasyPal image: Soyuz capsule being moved to launch site
1:09    MFSK16 closing announcements
:29     Surprise mode of the week

To decode EasyPal text and images, download the 4-May-2013 version of the program from vk4aes.com.

To decode the MFSK modes, use Fldigi from w1hkj.com or another digital decoding program.

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.

Please send reception reports to [email protected]

And visit voaradiogram.net (where any schedule or frequency changes will be posted)

Twitter: @VOARadiogram

Kim

Kim Andrew Elliott
Producer and Presenter
VOA Radiogram

Capture images on the VOA Radiogram this weekend

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VOARadioGram(Source: VOA Radiogram)

VOA Radiogram for the weekend of May 11 and 12 will feature long stretches of VOA News in plain text, using the MFSK 32 and 64 modes. No Flmsg or Flamp this time. This weekend’s program will also include our first test of slow scan television (SSTV).

Here is the lineup:

MFSK16 (2:28)     Preview

MFSK32 (12:08)     VOA News stories

The first of the three stories will be in Spanish. This is to determine how letters with accent marks appear on your display. The second VOA news story will be followed by an accompanying MFSK32 image

MFSK16     Intro to the next mode

MFSK64 (3:34)    VOA News story

MFSK16     Intro to the next mode

SSTV Scottie DX (4:31)

There are several software programs that decode SSTV, including Digital Master 780 (DM780) andMMSSTV. A free receive-only SSTV decoder is RX-SSTV from users.belgacom.net/hamradio/rxsstv.htm

MFSK16 (1:11)     Closing announcements

Closing music, accompanied by the surprise mode of the week

Please send reception reports to [email protected]

Screenshots and audio samples are welcome, especially audio of less than perfect reception conditions.

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.

 

Shortwave Radio Recordings: The Mighty KBC

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The Art of Noise kicks off this Mighty KBC broadcast. (Photo: Wikimedia Commons)

The Art of Noise kicks off this Mighty KBC broadcast. (Photo: Wikimedia Commons)

The Mighty KBC broadcast again early this morning (from 00:00-02:00 UTC) on their new summer frequency of 9,925 kHz. Their signal from Nauen, Germany was packing 125 kW–it was amazingly strong into North America. As we’ve come to expect, the KBC’s Giant Jukebox of music has a lot of rock-n-roll and Euro-pop variety, spanning the decades; DJ, “Uncle Eric” knows how to entertain and spin the tunes!

You can listen to the full recording below in the embedded player, or simply right click this link and save the MP3 file to your computer:

You’ll notice that Kim Elliott has another installation of digital text modes in this broadcast. Decode these digital modes using Fldigi from www.w1hkj.com. Be sure to check out Dr. Elliott’s VOA Radiogram website for full details about this broadcast.

VOA Radiogram for April 27/28 includes Thor50x2, PSK63F, and Flamp

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VOARadiogram(Source: VOA Radiogram)

Apologies for not updating this website since the April 20/21 VOA Radiogram. I have been diverted by deadlines connected to my other full-time job, audience research analyst for the International Broadcasting Bureau.

Thanks to all who sent reception reports, screenshots, audio samples, and other materials from the past weekend’s program. MFSK held off a challenge from the Thor modes and remains the most successful of the modes we have tested.

However, because your producer omitted the Thor 50×2 mode — a mode that might prove to be robust — from that program, VOA Radiogram on April 27/28 will include a “make good” transmission of Thor 50×2. And a transmission of Thor 50×1 for comparison.

There will also be a transmission of the PSK63F mode. This rather slow mode performed well during VOA Radiogram 1, but we only gave it a minute. There will be a longer transmission of PSK63F this weekend to allow a better evaluation.

The last text transmission this weekend will be in the Flamp format. If you don’t already have it, please download Flamp from www.w1hkj.com. Flamp divides a text file into several blocks, each with a specific number of characters. If any block is received without the correct number of characters, that block is rejected. The missing block can be picked up during the repeat transmission. Flamp might be useful for those text transmissions that are received at about 90% copy, when occasional deep fades prevent 100% copy. In Flamp, under Configure, check both of the Auto sync boxes.

Here is the lineup for the April 27/28 VOA Radiogram:

MFSK16 (58 wpm) program preview
PSK63F (55 wpm), 2:50
MFSK32 text (120 wpm) and image, 4:28
Thor50x1 (180wpm), 1:48
Thor50x2 (180wpm), 1:46
MFSK64 (240 wpm), 2:16
MFSK128* in Flamp X2 format, 3:46
MFSK32 image

*Probably a good idea to set the MFSK128 mode manually rather than depend on the RSID

All modes will be centered on 1500 Hz.

Each mode will be introduced by a brief MFSK16 transmission, same as last weekend.

Please send reception reports to [email protected]

Twitter: @VOARadiogram

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.

Kim