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Shortwave Data Decoding Discussions regarding decoding digital signals on the HF bands, including HFDL, ALE, RTTY, CW, and others.

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Old 03-09-2013, 2:35 PM
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Default VOA To Test Digital Modes

Yes, this actually crosses into more than one forum, so please bear with me for a moment.

Over the last few months, one or two SWBC stations have been broadcasting a digital signal along with their usual analog one. This is part of an experiment, started by Dr.Kim Andrew Elliott of the VOA, to see if news and other data can get to countries where jamming is otherwise a problem (such as Iran). As we know, there are some digital modes that, due to their narrow bandwidth or built in redundancy, are a candidate for such an experiment.

If you were at the Winterfest, you heard much more about this, along with a (partially) successful demonstration of various modes being copied in spite of jamming on a SWBC signal (The 'partially' is really a product of things not working well - the decoding worked fine during rehersals but sometimes went 'wonky' during the discussion. Curse of the Doubletree, I guess - I know 'cause the same thing happened to me 2 years ago...)

Anyway there have been several announcements about this on Glenn Hauser's DXLD Yahoo group, and here's another (from Kim) on the NASWA group...
=======================================
Digital text and images this weekend on The Mighty KBC:

http://voaradiogram.net/post/ 447085...the-mighty-kbc

Digital text IDs this weekend on WRMI, starting tonight midnight EST:

http://voaradiogram.net/post/4487057...eekend-on-wrmi

VOA Radiogram may launch on 16 March, if we can get all the technical ducks in a row. It will feature the PSK modes: BPSK, QPSK, and PSKR.
========================================

Although Kim was using FLDigi in his demo, there are other packages out there that could copy such transmissions. These include the well known MultiPSK and MixW, along with one or two lesser known ones such as Sorcerer. Please see the website in my sig for URLs for these and other packages.

If you are able to copy amateur digital transmissions successfully, you should be able to copy these, conditions permitting.

Mike
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Old 03-09-2013, 4:20 PM
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sounds like an interesting experiment, very keen to have a listen if I can get a reception on them
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Old 03-15-2013, 2:19 PM
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Default VOA To Test Digital Modes

May be of interest:




03/14/2013The Voice of America Radiogram show, hosted by Kim Andrew Elliot, KD9XB, will be testing a variety of digital modes on March 16 and 17.
The data transmissions can be decoded by anyone with an AM shortwave receiver using any of the popular sound-card-based programs such as Fldigi, Ham Radio Deluxe, MixW, MultiPSK, DigiPan (for BPSK31, BPSK63 and QPSK31 only),CocoaModem (for Macs) and others.
Each test will last one minute, unless otherwise specified, on the following modes at the audio frequencies indicated. During some tests as many as four modes will be used simultaneously . . .

BPSK31 at 2000 Hz
QPSK31 at 1000 Hz, BPSK31 at 2000 Hz
QPSK31 at 1000 Hz, PSK63F at 1500 Hz, BPSK31 at 2000 Hz
QPSK63 on 1000 Hz, PSKR125 at 1500 Hz, BPSK63 at 2000 Hz
QPSK125 at 1000 Hz, PSKR250 at 1500 Hz, BPSK63 at 2000 Hz
QPSK250 at 800 Hz, PSKR500 at 1500 Hz, BPSK250 at 2200 Hz
QPSK500 at 800 Hz, PSKR1000 at 1500 Hz, BPSK500 at 2200 Hz
PSKR500 at 1000 Hz, PSK63F at 1500 Hz, PSKR125 at 2000 Hz, and PSKR250 at 2500 Hz (5 minutes, 40 seconds total). The latter portions of the PSKR250 and 500 transmissions are formatted for Flmsg, a function within theFldigi software suite. (In Fldigi, go to Configure > Misc > NBEMS > under “Reception of flmsg files.” Click Open with flmsg and Open in browser and select the desired location of the flmsg.exe file.)
MFSK32 image on 1500 Hz (54 seconds)

The 30-minute Radiogram program is scheduled to air . . .
Saturday 1600 UTC at 17860 kHz
Sunday 0230 UTC at 5745 kHz
Sunday 1300 UTC at 6095 kHz
Sunday 1930 UTC at 15670 kHz
... from the IBB Edward R. Murrow Transmitting Station in North Carolina.
E-mail reception reports are welcomed at radiogram@voanews.com.
According to Elliot, future VOA Radiogram programs will transmit only one mode at a time. “This will ensure the highest possible signal-to-noise ratio and the best possible chances for a successful decode. These broadcasts are an experiment. We will try different modes in different programs to see which work best via AM analog shortwave broadcast transmitters.”
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Old 03-15-2013, 6:03 PM
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Moved to our HF digital decoding forum and merged with a previous thread on the same subject.

Doctor Kim (as his friends call him...) discussed this at length at the last Winterfest.

If there's enough interest, I may make this a sticky so these broadcasts can be tracked. If you do write Kim, please tell him you heard about it at RadioReference. I have secured permission for his announcements to be echo'ed here, so if you happen to see it, please add to this thread.

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Old 03-15-2013, 7:16 PM
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A very basic description on how to decode the digital modes for these experiments

VOA Radiogram

If you click on the URL on my sig, you will get taken to a page with lots of links for various packages that can do the job. As this page is devoted to more general usage decoding (rather than just hams), we'll also accept the URLs for other ham-related packages that can do the job in this thread.

To start, here's the one for CocoaModem;

cocoaModem

and for Ham Radio Deluxe, which has DM780 as part of it's integrated package...

Ham Radio Deluxe

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Old 03-15-2013, 9:25 PM
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Will potential listeners/viewers in the target areas be able to afford the gear necessary to decode these transmissions?

"PSKR250 and 500 transmissions are formatted for Flmsg, a function within theFldigi software suite" ???
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Old 03-15-2013, 9:52 PM
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For these and other modes used on KBC Radio and the new VOA broadcasts, many of us have been using the FLdigi package found at W1HKJ Software and it is available for Windows, MAC and Linux. Those with HF transmitting privs (or a SW receiver in SSB if you don't), you can pick up the NBEMS (Narrow Band Emergency Messaging System) nets around the country. We have the NY-NBEMS net on Saturdays at 10AM (local eastern) and the USeast-NBEMS net on Wednesdays at 7PM (local eastern) on 7.036 USB with a waterfall spot of 1500 hz (Information on Narrow Band Emergency Messaging Services).
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Old 03-16-2013, 4:29 AM
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Another way to test your setup is to check out the ARRL digital transmissions, and (to bring us back to non-ham broadcasts) the USCG SITOR schedule, the links for which are below

Digital Transmissions

USCG HF SITOR

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Old 03-16-2013, 12:07 PM
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I just got in on the last 18 minutes of the 17860 broadcast and recorded it. If you are interested
http://sdrv.ms/111Y794
It is almost a gig, uncompressed .wav file

Bruce
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Old 03-16-2013, 7:20 PM
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Quote:
Originally Posted by k9rzz View Post
Will potential listeners/viewers in the target areas be able to afford the gear necessary to decode these transmissions?
A legitimate question...

While it's certainly possible that these transmissions are being heard worldwide, the target audience for this experiment, I think, is intended to be US listeners. With a recent change in the VoA charter (I have forgotten the name of the bill that changed this), they can now broadcast to us legally. They are, in fact, doing it now via Internet streaming (on the Pure Connect website) and no doubt others.

I doubt that anyone in a third world country away from a major city would be able to copy these transmissions, but for folks in a major city in, say Iran or China, it just might be possible. Internet cafes are common in major cities these days, even if they are under some government controls. And Internet awareness in such environments by youth is very high. so at least for them, it is possible. They may even have their own PC and network, if somewhat secretly.

However it's probably too early in the experiment to draw any real conclusions as to the target audience and its effectiveness. Right now, it's only that - an experiment. Whether it gets beamed to other countries on a regular sked has yet to be decided, AFAIK

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Old 03-22-2013, 11:52 AM
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The next scheduled test (thanks to DXLD for alerting me...)

VOA Radiogram

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Old 03-23-2013, 3:06 PM
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And some additional news from other stations participating in the test...

Kim Andrew Elliott reporting on International Broadcasting

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Old 03-25-2013, 12:58 PM
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I find it odd that a digital signal traveling on a shortwave frequency can be effectively decoded. Don't you need precise audio? I ran various decoders and just decoding on UHF is a PITA if the signal is weak. Just a random thought.
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Old 03-25-2013, 1:43 PM
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What do you mean by 'precise audio'?

Hams have been doing this for many years, and up to perhaps 15-20 years ago, there were many stations broadcasting clear text RTTY for news services and such. They're long gone (moved to satellites and other methods)

Part of this experiment is to test the reliability of certain digital modes with either a very narrow bandwidth or with error-correcting features to overcome the effects of jamming. Under normal conditions a clear, unencrypted signal can (sometimes) be decoded (there are MANY stations that use HF digital with all sorts of scrambling...), but this is the first time something like this has ever been attempted. In fact many of the modes that are being tested were developed by hams.

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Old 03-28-2013, 4:47 PM
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Hello all,

I decoded this Digit Broadcast Saturday of 17860 and Sonday of 15670 Khz, this is my decoded extract, signal was no so good in Northeast France, I can all mode decoded except PSK1000R no unterstand !!! and PSK125R Plain text only in normal text :


PSK31 :

VOA NEWS

Asteroid's Spin Intrigues Astronomers

Suzanne Presto

February 14, 2013

Astronomers hope to learn more about Asteroid 2012 DA14's features and composition as it flies past Earth at
about 7.8 kilometers per second - far faster than a speeding bullet...


PSK63 :

VOA NEWS

Asteroid's Spin Intrigues Astronomers

Suzanne Presto

February 2013

Astronomers hope to learn more about Asteroid 2012 DA14's features and composition as it flies past Earth at
about 7.8 kilometers per)econd - far faster than a speeding bullet. But that's not all they hope to discern
when the object comes within 28,000 kilometers of our planet on February 15.

Spin

Michael Busch is a planetary astronomer at the National Radio Astroobservatory in the southwestern U.S.
state of New Mexico. He says the direction of...


PSK125R :

VOA NEWS

Asteroid's Spin Intrigues Astronomers

Suzanne Presto

February 14, 2013

Astronomers hope to learn more ahe-= h2012 DA14's features and composition as it flies past Earth at
about 7nOoLtOnndeper second - far faster than a speeding bullet. But that's not all they hope to discern
when thiVirt--thin 28,000 kilometers of our planet on February 15.

Spin

Michael Busch is a planetary hra t[yadt the National Radio Astronomy Observatoreli i"-b-tern U.S.
state of New Mexico. He says the direction of DA14's spin is important in predicting the way its orbit will...


PSK125R plaint text : only normal text

VOA NEWS

NASA Captures First Images of ISON Comet

VOA News

February 07, 2013

NASA has captured the first images of a distant comet, which may give us a spectacular light show later this
fall.

The images of comet C/2012 S1 (ISON), were taken by NASA's Deep Impact spacecraft from January 17 and 18 when
the comet was 493 million miles away, according to a NASA release.
/n-i <ENQ>bis the fourth comet on which we have performed science observations and the farthest point from Earth from which we've tried to transmit data on a comet," said Tim Larson, project manager for the Deep Impact spacecraft at NASA's Jet Propulsion Laboratory
in Pasadena, Calif. "The distance limits our bandwidth, so it's a little like communicating through a modem after being used to DSL. But we're going to coordinate our science collection and playback so we maximize our return on this potentially spectacular comet."

As comets approach, the sun's energy warms them, releasing gas and dust which form a comet's luminous tail. While ISON is still distea taays it is already active, with a tail extending more than 40,000 miles form the comet's nucleus. ISON is expected to come as
close as 40 million miles to Earth on December 26 of this year.

ISON is known as a long-period comet. These can have orbits lasting hundred, thousands or even millions of years. NASA believes this is ISON's first orbit, which means it is likely "laden with volatile material just spoiling for some of the sun's energy to heat it
up and help it escape." That could mean quite a show, but NASA cautions the comet could break up as well.

Would-be comets are thought to dwell in the solar system's Oort cloud, som Glsonae icalls a "giant spherical cloud of icy bodies surrounding our solar system so far away its outer edge." When these bodies are disturbed by the l!fae<ETX>tcefects of passing or nearby
stars, they can be "nudged" from the cloud and begin their long orbits around the Sun.

ISON was discovered on Sept. 21, 2012, by two Russian astronomers using the International Scientific Optical Network's 16-inch (40-centimeter) telescope near Kislovodsk.

http://www.voanews.com/content/nasa-.../159911…

VOA Radiogram
VOA Radiogram
radiogram@voanews.com

+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V|O|A| |R|A|D|I|O|G|R|A|M|
+-+-+-+-+-+-+-+-+-+-+-+-+-+


PSK250R : formated Flmsg :





MFSK32 picture :




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Old 03-29-2013, 12:37 AM
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Quote:
Originally Posted by k9rzz View Post
Will potential listeners/viewers in the target areas be able to afford the gear necessary to decode these transmissions? ???
The answer is no. These transmissions are just for hobbyist (and I'm one of them).
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Old 03-29-2013, 4:23 AM
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While that may be true for the purposes of this experiment, the target - if this does go live to countries like Iran and China - would make answering this question a bit dicey.

I suspect it will only work in the larger cities where things like Internet cafes would make downloading the necessary software possible. In places like Iran and China, while access is often government controlled, there have been many who found ways to circumvent this.

The real question is to consider who has the money to afford a laptop to be able to decode these transmissions. There, I'm afraid, things tend to fall short, although some of the decoding packages don't need much horsepower to run.

Mike
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Old 03-29-2013, 8:08 PM
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The next schedule, via the UDXF group...
====================================
Subject: VOA Radiogram MFSK show 30-31 March

To the VOA Radiogram monitoring group:

VOA Radiogram on 30 and 31 March 2013 will feature the MFSK (multiple frequency shift keying) modes. This "menu" for the program shows the mode, center audio frequency, and duration of transmission in minutes:seconds. ..

MFSK4 1500Hz 0:40*
MFSK16 1500Hz 1:00
MFSK32 1000Hz 1:00
MFSK32 2500Hz 1:00
PSKR125 2500Hz 1:00
PSKR250 2500Hz 1:00
MFSK64 2500Hz 1:00
MFSK64 2500Hz 3:07 Flmsg format
PSKR500 2000Hz 0:58
MFSK128 2000Hz 0:57**
MFSK32 2000Hz 1:40 Image
MFSK32 1500Hz 0:58 Image

* No RSID. You must tune the audio frequency very carefully. (Don't worry if it does not work!)

**The RSID might not work, so manually select MFSK128 (needs new version of Fldigi) and the 2000 Hz center audio frequency.

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 reports, audio samples, screenshots, etc to voaradiogram@ voanews.com.

If you are unable to listen to the program because of Easter weekend, this MFSK show will be repeated later this year.

I am grateful for all the reports and attachments you have sent for the previous (PSK) editions of VOA Radiogram.

Kim Andrew Elliott

http://voaradiogram .net

Twitter: @voaradiogram

=================

Let's be careful about the very wide displays - it makes messages hard to read, particularly on laptops. There are many good image cropping utilities out there, I'm sure...thanks...Mike
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Old 03-30-2013, 3:16 PM
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Hello, I receive this afternoon VOA with Digit Test auf 17860 Khz in MFSK32 two pictures :



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Old 03-30-2013, 9:56 PM
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Be sure to email/twitter Kim when you get these broadcasts. The more reports he gets, the better the data for evaluating the experiment....and let him know you heard about it on RadioReference

Mike
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