Tag Archives: Digital Modes

BBC World Service features DRM

In this BBC World Service report, Mark Whittaker explores Digital Radio Mondiale (DRM) and, especially, its potential in India. Use the embedded player or link below to listen:

(Source: Audioboo via Tarmo Tanilsoo on Facebook)

drmlogoYou’ll note the BBC World Service fails to mention that DRM has been in use now for over a decade.

The report ends by suggesting that portable DRM receivers will be on the market in a few months. Even if DRM radios start appearing, whether or not they’ll be effective and inexpensive remains to be seen. So far, portable DRM radios have been mediocre performers (at best) and relatively expensive.

Don’t get me wrong: I would love to see DRM take hold, I just have my doubts. DRM might stand a chance if a manufacturer like Tecsun were to build an inexpensive portable radio, with a form factor much like that of their other portables. If they made a DRM version of the PL-380, for example, it could be a winner for both the company and the medium/mode.

By the way, if you’ve never heard what DRM sounds like over the shortwaves, I just posted a fifty eight minute recording of All India Radio on the Shortwave Radio Audio Archive. Contributor, Mark Fahey, recorded the broadcast from his home in Australia.

I’ve embedded a link to the audio below, but you can listen to the broadcast and read Mark’s notes on the shortwave archive (click here).

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VOA Radiogram: Battle of the 100 wpm modes, this weekend!

VOARadioGramIf you like the VOA Radiogram, don’t miss this weekend (March 29-30)–a one year mile marker for the VOA Radiogram service on shortwave radio.

I’ve copied details of the broadcast below, but please bookmark or subscribe to the VOA Radiogram website to see the results of the 100 wpm battle and details of all future broadcasts.

(Source: VOA Radiogram)

This weekend, 29-30 March 2014, will be program 52 of VOA Radiogram. This means that VOA Radiogram has survived one year of shortwave broadcasting.

VOA Radiogram has been successful because of its audience: tuning in, decoding, experimenting, and sending in reports.

We will mark one year of VOA Radiogram with a “battle of the 100-word-per-minute modes.” The same VOA News story will be transmitted using four modes that have a speed of more-or-less 100 words per minute.

Here is the lineup for VOA Radiogram, program 52, 29-30 March 2014:

  •  1:51  MFSK32: Program preview
  •  3:28  PSKR125 (110 wpm): VOA News re Ethiopia
  •  7:42  MT63-1000L (100 wpm): Same VOA New story
  • 12:34  Thor25x4 (100 wpm): Same VOA News story
  • 17:58  MFSK32 (120 wpm): Same VOA News story, with image
  • 23:55  MFSK32: US international broadcasting FY2015 budget
  • 25:58  MFSK32: Closing announcements, with image

Each mode will be preceded by 5 seconds of silence, followed by the RSID, 5 more seconds of silence, and the RSID again.

Please send reception reports to [email protected]

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.

(Many shortwave broadcast frequencies will change on 30 March with the beginning of the A14 season, but the VOA Radiogram frequencies stay the same, for the time being.)

The Mighty KBC, via Germany, will again transmit a minute of MFSK64 Saturday at about 1230 UTC on 6095 kHz and Sunday at about 0130 UTC on 7375 kHz. (KBC’s change from 7375 to 9925 planned for this weekend has been postponed until May.) STF Radio International will also have a minute of digital modes during the same hour (simultaneous MFSK32 streams at 1500 and 2100 Hz).

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VOA Radiogram includes EasyPal comparison this weekend

VOARadioGram(Source: VOA Radiogram)

During the weekend of 29-30 June 2013, VOA Radiogram will continue experiments with the EasyPal digital image software. EasyPal will be transmitted in both its 4-QAM and 16-QAM settings to see if the former can be decoded in conditions where the latter cannot. Download EasyPal from  vk4aes.com.

VOA Radiogram for 29-30 June 2013:

2:31  MFSK16: Program preview

4:19  MFSK32: VOA News: “super-earths”

2:05  MFSK32: Accompanying image

:23  MFSK32: Introduction to MFSK64

2:15  MFSK64: VOA News: China space mission

2:53  MFSK32: Accompanying image

:33  MFSK32: Introduction to EasyPal

7:00  EasyPal 4-QAM: “super moon” in Greece

2:40  EasyPal 16-QAM “super moon” in Singapore

1:08  MFSK16: Closing announcements

:24  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
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VOA Radiogram features EasyPal digital images this weekend

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

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VOA, Mighty KBC and PCJ: Radiograms this weekend

The Mighty KBC, the VOA and PCJ radio will broadcast radiograms (digital text) over shortwave radio this weekend.

Reception conditions could be challenging depending on the impact of the incoming CME (Coronal Mass Ejection) which is expected to disrupt the high frequency bands today. All the more reason to attempt to decode these messages as Dr. Kim Elliott is studying each digital mode and its ability to effectively overcome adverse conditions. Email your reports and audio files to: [email protected]

Here are details from each broadcaster:

KBCradioThe Mighty KBC

Broadcasting 14 April 2013 from 00:00-02:00 UTC on 7,375 kHz.

At about 0133 UTC, two slow (less than 60 WPM) but robust modes will be transmitted: Olivia 8-1000 centered on 1000 Hertz, and MFSK16 on 2000 Hertz.

At just before 0200 UTC, Olivia 8-2000, with Flmsg format, will be centered on 1500 Hertz.

VOARadioGramThe Voice of America

VOA Radiogram for the weekend of 13/14 April 2013 will feature the Olivia modes, with MFSK modes also transmitted for comparison.

The modes will be transmitted in groups of three, and all will be centered on an audio frequency of 1500 Hertz, except where indicated:

Olivia 8-1000, 58 WPM, 1:32 (program menu)
MFSK 16,  58 WPM, 1:52
Olivia 8-1000, 58 WPM, 1:44

Olivia 32-2000, 50 WPM, 2:09
MFSK 22, 80 WPM, 1:50
Olivia 16-2000, 80 WPM, 1:51

MFSK 32, 120WPM, 2:04
Olivia 8-2000, 120WPM, 2:04
Olivia 4-2000, 160WPM, 1:40

Olivia 16-1000 (centered on 2000 Hz) versus music, 2:03

MFSK 32 closing text and image,  :51

Reception reports with (if possible) sample audio and screenshots would be appreciated. Audio files from outside the United States are especially helpful.

[email protected]

Twitter: @VOARadiogram

Here is the VOA Radiogram broadcast 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.

pcjPCJ Radio

PCJ Radio will transmit text on 14 April 2013 at 02:27 UTC via WRMI, Radio Miami International on 9,955 kHz. The mode will be Olivia 8-1000.

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VOA Radiogram: March 23/24 broadcast

VOARadioGram(Source: VOA Radiogram)

VOA Radiogram for March 23/24 will be similar to the past weekend’s program in that it features the PSK modes. Much of Kim’s script will be the same. In this weekend’s broadcast, however, only one mode at a time will be transmitted. This should improve the signal-to-noise ratio and ability to decode each mode.

Each will be centered on 1500 Hz:

  1. BPSK31 (1:00)
  2. PSK63F (1:00)
  3. BPSK63 (1:00)
  4. PSKR125 (1:00)
  5. PSKR250 (1:00)
  6. PSKR500 (1:00)
  7. PSKR1000 (1:00)
  8. PSKR125 (3:45) Plain text
  9. PSKR250 (2:40) Flmsg* formatted (with html)
  10. MFSK32 (0:55) Image

*Install Flmsg. Then, in Fldigi: Configure > Misc >  NBEMS > under Reception of flmsg files click Open with flmsg and Open in browser, and below that state where your Flmsg file is located.

If decoding performance is still not satisfactory, VOA Radiogram in future weekends will feature more robust modes, such as MFSK, MT63, and Olivia.

See VOA Radiogram: how to decode the modes.

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, audio samples, screenshots, etc.,  to [email protected]

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The Mighty KBC testing fast digital modes this weekend

KBC Propagation Map (Source: The Mighty KBC)

KBC Propagation Map (Source: The Mighty KBC)

The Mighty KBC will broadcast this Sunday (January 20) on 9,450 kHz between 00:00-02:00 UTC (that’s Saturday night in North America from 19:00-21:00 EST). Details below:

(Source: The Mighty KBC)

We will try some fast text modes this weekend on The Mighty KBC, to see if they can survive the rigours of shortwave.

This will be during the North America broadcast at 0000-0200 UTC 20 January on 9450 khz. At about 0130 UTC, 4XPSK63R will be centered on 1000 Hz and MFSK64 centered on 2000 Hz. (For 4XPSK63R, use Fldigi 3.21.65 or newer: OpMode > PSKR > MultiCarrier > 4XPSK63R.) At just before 0200 UTC, MT63-2000 (long interleave) will be centered on 1500 Hz, and PSKR250 on 2800 Hz. This will be an Flmsg formatted transmission, with html. Fldigi and Flmsg can be downloaded from www.w1hkj.com.

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