Tag Archives: Radiogram

Dear BBG: Take note of the Radiogram!

VOARadiogramImagesMany thanks to my friends, Bennett Kobb (AK4AV) and Christopher Rumbaugh (K6FIB) who wrote a letter to the BBG regarding the relevancy of shortwave radio. They make a strong point as this article in Radio World puts it: “Hey, don’t forget about Radiogram!

I also made a case for the VOA Radiogram in my letter to the BBG, but I think Benn and Chris sum it up better. Click here to download their letter to the BBG as a PDF document–I’ve also pasted it below:

Response to BBG Shortwave Committee Request for Comment

March 14, 2014

The BBG has spearheaded ‘Radiogram’ (voaradiogram.net), an entirely novel form of international high-frequency broadcasting. Radiogram is soundly premised on modern digital techniques and mitigates longstanding impediments to HF transmission. Users around the world have documented reception of fifty VOA Radiogram programs in more than a thousand YouTube videos.

BBG must not allow its own pioneering developments to wither, but should advance them toward operational status.

Radiogram should not be confused with Digital Radio Mondiale (DRM), which employs digital modulation for sound broadcasting. Radiogram broadcasts web content via robust, interference-resistant, error-detecting/correcting AM tone modulation, using standardized formats widely practiced in the Amateur Radio Service.

The user’s ordinary shortwave receiver, tuned to a Radiogram transmission, feeds its audio to a user device. These could include mobile phones, tablets, laptop and desktop computers and the new ARM-based miniature computers and embedded devices. The user device decodes the tones and displays text and imagery despite propagation impairments and intentional interference — and without Internet connection.

Placing the radio near the phone or computer is normally sufficient. No hardwire connection is required. By adding a simple audio cable between receiver and user device, however, reception can be silent and covert. No specialized hardware is needed, and the software platform for decoding is long in the public domain.

A more advanced, yet still inexpensive setup would use existing “dongle” technology that places a software-defined radio (SDR) inside a small USB enclosure. Such units are available today for a few tens of dollars and widely used by experimenters. The operating system and decoding software could also be incorporated into the device, which could boot the computer, eliminating the need to install any PC software.

The user need not be present at the time of transmission to receive content. He essentially receives a web magazine updated at will and always ready for use. The user can redistribute it by printing, USB storage, SMS, E-mail etc.

Naturally, the audio tone transmission can be recorded for later playback. Even when buried well under music or noise, the nearly inaudible recorded broadcast can nevertheless deliver 100% copy upon decode.

Radiogram’s transmission methods provide text at 120 WPM (near to the speed of spoken English) along with images. Additional languages have been proven, including non-Roman alphabets.

Sent over regular broadcast transmitters (no modifications needed), this approach effectively extends the reach of the transmitter. In other words, the digital text mode will decode in locations where the audible speech over the same transmitter would be too low for aural intelligibility. The audio recorded or captured could be replayed over another transmitter to even further extend the reach of the broadcast.

Recommendations

BBG should:

1. Capitalize on Radiogram as a circumvention tool, readily consumable by mobile devices. It should integrate Radiogram into its media strategy and networks.

2. Retain, but reconfigure as necessary its HF facilities in view of the potentially lower costs and greater efficiency of Radiogram when compared to conventional sound broadcasting.

3. Support the development and wide distribution of simple, usable, open-source Radiogram decoding applications for popular mobile devices and platforms (Android, iOS, Windows, Mac, Linux), derived from the free Fldigi software used worldwide.

About the Respondents

Bennett Z. Kobb, M.S., SMIEEE, is the communications director for an Arlington, Virginia trade association.

Christopher Rumbaugh, MLS, is a library manager and web publisher in Salem, Oregon.

The views expressed herein are the authors’ own.

Again, many thanks to Benn and Chris for submitting such an articulate letter to the BBG and for sharing with SWLing Post readers.

If you would like to decode a VOA Radiogram yourself, simply visit VOAradiogram.net for details on broadcasts targeting your part of the world.

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

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 radiogram@voanews.com

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

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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: radiogram@voanews.com

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.

radiogram@voanews.com

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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