3/17/2014 2:27 PM
Paul McLane is
editor of Radio World.
Hey, don’t forget about
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
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
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.
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.
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.
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
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.
window to comment to BBG about shortwave has closed, but we welcome ongoing
discussion. Post below or send letters to the editor to email@example.com