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Mar 17

Written by: Paul McLane
3/17/2014 2:27 PM 


Paul McLane is editor of Radio World.

Hey, don’t forget about Radiogram!

That’s what Bennett Kobb and Christopher Rumbaugh are telling the Broadcasting Board of Governors.

BBG, as longtime readers know, oversees U.S. international broadcasting organizations like Voice of America and Radio Free Asia. The board in recent years has been following a path trod by other large shortwave broadcasters, scaling back use of traditional shortwave infrastructure in favor of online, FM, TV and other media channels.

The organization has emphasized that it remains committed to using shortwave where it is needed. Nevertheless, many facilities have closed over the years, and BBG recently established a committee to research the future of shortwave as it relates to U.S. public policy and national security. It sought public comments.

Among those replying were Kobb and Rumbaugh. One works for a trade association, the other is a library manager and web publisher; but they were writing as individuals.

They want to draw attention to VOA Radiogram, a form of international high-frequency broadcasting. Radiogram is a VOA program experimenting with digital text and images via shortwave broadcasting; it’s produced and presented by Dr. Kim Andrew Elliott.

“Radiogram is soundly premised on modern digital techniques and mitigates longstanding impediments to HF transmission,” Kobb and Rumbaugh wrote in their comments to BBG. “Users around the world have documented reception of 50 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.”
Kobb noted this image of a car, posted on the Radiogram site and illustrating  good quality obtained by listeners in several countries. The captions state the location received and time of the VOA broadcast.

Radiogram broadcasts Web content via error-detecting/correcting AM tone modulation, using standardized formats commonly used by ham radio. They say this approach is robust and resistant to interference.

“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.”

They point out that no hardwire connection is required; putting the radio near the phone or computer is usually sufficient. “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 news story received with VOA logo.

They have further ideas. Another approach would use “dongle” technology that puts a software-defined radio inside a USB enclosure. “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 to receive content, and essentially receives a web magazine “updated at will and always ready for use” that can be redistributed.

“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 words per minute, along with images.

“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.”

They conclude that BBG should capitalize on Radiogram as a “circumvention tool, readily consumable by mobile devices,” and integrate Radiogram into its media strategy and networks. They want the board to reconfigure HF facilities with Radiogram in mind, and support development and distribution of open-source Radiogram decoding applications for mobile devices and platforms.

The window to comment to BBG about shortwave has closed, but we welcome ongoing discussion. Post below or send letters to the editor to radioworld@nbmedia.com.

 

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Location: Blogs Parent Separator Paul McLane

6 comment(s) so far...


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Re: Hey Don't Forget About Radiogram

This is wonderful. I can hardly wait for the utilization of short wave radio for something positive
and useful once more.

By Troy Spencer on   3/18/2014 5:14 AM
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Re: Hey Don't Forget About Radiogram

You just never know what might happen to the internet. This seems pretty low-tech in these times of internet connections measured in the Mb/sec and Gb/sec. But with this, no worries of a government hostile to open communications be able to block messages by shutting down their internet.

We should never abandon SW completely. You never know when we might need it.

By Russ Johnson on   3/18/2014 5:14 AM
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Re: Hey Don't Forget About Radiogram

Another (unstated) advantage of the digital communication modes is that a lot of distance can be gotten using very low power. In the amateur community digital transmissions can be logged internationally using power of less than 100w. And the system is robust as well using error correcting codes.

By John Unrath on   3/19/2014 5:29 PM
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Re: Radiogram PLUS Analog SW please and thank you

I agree with Russ - analog AM SW should never be abandoned by the US Government as it is a last line of information to the mass public along with 50KW clear frequency analog AM stations. Most of the 'emergency' (hand-crank power) radios have SW in addition to AM/FM so SW needs to remain an option. Using digital to supplement the analog SW is a great idea and one that I want to try. A USB dongle made to order for this service would be a great idea.

By John Pavlica on   3/20/2014 10:33 AM
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Re: Hey Don't Forget About Radiogram

There are many reasons to keep shortwave alive, and Radiogram is definitely one of them! Things are quickly progressing to the point that a small circuit board, a decent-length whip and a 9V battery or solar cell would be enough to receive digital media freely anywhere in the world via technology like Radiogram.

I regularly make worldwide contacts with technology like this using just 35 watts of power and a 60-foot dipole, needless to say VOA has a bit more to work with.

Thanks for using a screenshot of my recordings, I do them just about every weekend and post them to YouTube, just search for "k0rusham".

By K0RUS on   3/20/2014 10:33 AM
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Radiogram is the Kiddie Version of Digital Radio Mondiale

Although I'd like to see dedicated hardware for decoding Radiograms using MFSK, DRM is the only viable digital contender on the ALL broadcasting bands including . Due to the ridiculously low-power recommendations for digital (40% analog), DRM suffers needlessly on the shortwave bands using a Main Service Channel (MSC) of 64 QAM. Even at a 40% analog power level, DRM on shortwave is VERY reliable IF broadcasters would use a MSC of 16 QAM instead of 64 QAM.

By TP Reitzel on   3/28/2014 9:57 AM

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