Tag Archives: Digital Modes

Guest Post: Monitoring Digital Selective Calling (DCS) with YADD

Many thanks to SWLing Post contributor, Don Moore–noted author, traveler, and DXer–for the following guest post:


Photo by Borderpolar Photographer

Monitoring DSC with YADD

By Don Moore

(The following article was originally published in the April/May 2022 edition of the Great Lakes Monitor, bulletin of the Michigan Association of Radio Enthusiasts. An all-band listening club, MARE publishes a bi-monthly print bulletin and a weekly e-mail loggings tip-sheet. The club also holds regular get-togethers, picnics, and DXpeditions, generally in southeastern Michigan.)

There are dozens if not hundreds of different digital modes used for communication on the MF and HF bands. These aren’t broadcasts you want to listen to unless you like to hear weird tones, beeps, warbles, and grinding noises interspersed with static. Digital modes are for monitoring, not listening. And monitoring them requires having software that does the listening for you and converts the noises into something meaningful – like the ID of the station you’re tuned to. The learning curve to DXing digital utilities can be steep. There are lots of modes to identify and the software can be complicated to learn. Some broadcasts are encrypted so you can’t decode them no matter how hard you try. But the reward is lots of new stations and even new countries that you wouldn’t be able to add to your logbook otherwise.

One of the easiest digital modes to DX is DSC, or Digital Selective Calling. DSC is a defined as “a standard for transmitting pre-defined digital messages.” Look online if you want to understand the technical specifications that specify the values, placement, and spacing of the tones. The result of those specifications is a string of three-digit numbers like this:

125 107 125 106 120 105 120 104 000 120 022 120 041 000 002 022 020 041 108 002 053 020 080 108 006 053 021 080 070 006 118 021 126 070 126 118 126 126 126 126 126 126 126 126 126 126 117 126 112 126 117 117 117 112 109 125 108 125

Each three-digit value represents either a digit or a key word and the positions of the values map to the various fields contained in the message. This message, which was received on 8414.5 kHz, is a test call from the tanker Brook Trout to the coastal station Coruña Radio in Spain. The sender and destination are not identified by name but rather by their nine-digit MMSI (Maritime Mobile Service Identity) numbers – 538006217 for the vessel and 002241022 for the coastal station.

GETTING STARTED WITH DSC

Logging DSC stations requires three pieces of software. First you need a decoder program that turns the noises into numbers and the numbers into meaning. There are several free and commercial options but the most popular one for beginners is YADD – Yet Another DSC Decoder. YADD is free and easy to set up and while YADD can be used by feeding the audio from a traditional radio into your computer, the most common use is with an SDR. That’s what I use and what I will describe here.

Second you need an SDR application and an SDR. I prefer HDSDR for most of my SDR use but I like SDR-Console for digital work. But any SDR program will work if you can feed the audio to a virtual audio cable. And that’s the final thing you need – a virtual audio cable to create a direct audio connection between your SDR application and YADD. There are several different ones available but I recommend VB-Cable. Your first VB-Cable is free and that is all you need to run a single instance of YADD. If you want to expand you can buy up to four more cables from them later. Continue reading

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Radio Waves: Data RX via Web SDRs, Mystery Signals from Space, Public Media’s role in Democracy, and Pirates SPAM UVB-76

Radio Waves:  Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Marty, Troy Riedel, and Rich Cuff for the following tips:


Receiving data with web based shortwave radios (Nuts and Volts)

Your computer and the Internet give you free access to over 100 web based shortwave receivers that you can use as if they were your own. Unfortunately, employing these radios to decode data transmissions can be very difficult or impossible — unless you know the secret.

[…]A while back, I discussed how to receive data signals with a low cost shortwave radio (N&V May 2015). Now, the concept takes on a new dimension since we are using virtual radios not in our possession.

As astonishing as it seems, many of these Web based shortwave receiver data signals can be processed and decoded using just your PC and some free decoding software. Yes, some signals are encrypted, and can’t be decoded. Fortunately, there are plenty of unencrypted data signals around to keep us busy for a long time.

However, as will be discussed later on, it does require a special trick to allow you to pipe the streaming audio signals from the Web to the decoding software. In this article, I will show you how to use these Web based shortwave receivers to access data transmissions and to get started in this exciting hobby. [Click here to read the full article…]

Unknown objects at the heart of the Milky Way are beaming radio signals, then mysteriously disappearing (Business Insider)

Ziteng Wang found a needle in an astronomical haystack.

Wang, a physics PhD student at the University of Sydney, was combing through data from Australia’s ASKAP radio telescope in late 2020. His research team had detected 2 million objects with the telescope and was classifying each one.

The computer identified most of the stars, and the stage of life or death they were in. It picked out telltale signs of a pulsar (a rapidly rotating dead star), for example, or a supernova explosion. But one object in the center of our galaxy stumped the computer and the researchers.

The object emitted powerful radio waves throughout 2020 — six signals over nine months. Its irregular pattern and polarized radio emissions didn’t look like anything the researchers had seen before.

Even stranger, they couldn’t find the object in X-ray, visible, or infrared light. They lost the radio signal, too, despite listening for months with two different radio telescopes. [Continue reading…]

Do countries with better-funded public media also have healthier democracies? Of course they do (Nieman Lab)

But the direction of causality is tricky. Do a democracy’s flaws lead it to starve public media, or does starving public media lead to a democracy’s flaws?

There’s a new book coming out in the U.K. this week called The BBC: A People’s History, by David Hendy. Its publisher calls it a “monumental work of popular history, making the case that the Beeb is as much of a national treasure as the NHS…a now global institution that defines Britain and created modern broadcasting.”

Cross the pond: While Americans generally like PBS and NPR, I wouldn’t expect them to come up quickly if you asked someone on the street to begin listing national treasures. (I’m even more sure America’s health care system would go unmentioned, too.) Who “created modern broadcasting” in the U.S.? It certainly wasn’t the two public broadcasters that didn’t hit airwaves until 1970. And what TV network is a “global institution” that “defines” the United States abroad? Apologies to PBS Newshour, but that’s CNN.

No one says “Auntie Peebs.”

It’s obvious that the U.S. approached the new broadcasting technologies of the 20th century in ways wildly different from their European peers — and in ways that reflect on the countries themselves. American radio began wild and unregulated, experimental, a bubbling font of creativity — and then quickly became commercialized, optimized for mass audiences and massive profits. The BBC, which turns 100 this year, was more structured, more statist, more controlled — but has remained more central to residents’ lives, more civic-minded, and more beloved. [Continue reading…]

Pirates Spammed an Infamous Soviet Short-wave Radio Station with Memes (Vice)

The UVB-76 numbers station took a break from being a suspected communications tool of Russian intelligence to blast ‘Gangnam Style’

Pirates hijacked an infamous short-wave radio station, which dates from the Soviet era but is still online today, and used it to broadcast everything from Gangnam Style to audio that draws memes when inspected under a spectrum analyzer.

For decades the numbers station known as UVB-76 has emitted an enigmatic series of beeps and a voice reading numbers and names, in what people suspect is a long running communications method for Russian intelligence. Since the broadcast is public, pirates are able to use their software-defined radio (SDR) transmitters to effectively flood the frequencies with noise and memes.

The recent barrage of attacks on the station come as Russia prepares to invade neighbouring Ukraine, where radio enthusiasts speculate at least some of the pirate broadcasts originate. [Continue reading…]


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Bill recommends Slow Scan Radio

Many thanks to SWLing Post contributor, Bill Hemphill (WD9EQD), who writes:

I have enjoyed listening to Scow Scan Radio SWL Program.

I used a WebSDR to receive it.

http://www.slowscanradio.com/

But it has been off the air for the past weeks due to some minor health issues. The program was interesting in that besides Slow Scan photos, he also did other digital modes using FLDigi.

Some of the test included multiple digital signals in the same waterfall.

When I went to website today to check to see if there were any updates on when it might return to the air, I discovered that he is doing a podcast: Daily Minutes Podcast. Following is podcast feed:

https://dmpodcast.net/feed/

This podcast is a combination of new items as well as some re-runs of earlier Show Scan Radio programs. They also are a combination of English & Dutch. The June 13 & 14 podcasts are about off-shore radio. Very interesting and enjoyable.

The Jun 12 & 14 podcasts include a re-run of an earlier Slow Scan Radio Show in the last thirty minutes of the podcast.

[The screen shot at the top of the page is a] sample of the start of the digital portion.

Very cool! Thank you for sharing this, Bill!

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FT4 digital mode now available in WSJT-X release candidate 5

Joe Taylor presenting FT4 at the Fair Lawn Amateur Radio Club

(Source: Southgate ARC)

The new amateur radio digital mode FT4 is now available for download as part of WSJT-X Release Candidate 5

You can download wsjtx-2.1.0-rc5-win64.exe (or for other O/S) from near the bottom of the page at
http://physics.princeton.edu/pulsar/k1jt/wsjtx.html

FT4 Protocol document
http://physics.princeton.edu/pulsar/k1jt/FT4_Protocol.pdf

See the WSJT Group at
https://groups.io/g/WSJTX/

For more information about FT4, check out this previous post.

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Ham Radio Digital Modes: Joe Taylor talks FT8 and introduces FT4

Many thanks to SWLing Post contributor, Pete Eaton, who shares the following note and video:

Here is a You Tube Video of a presentation given by Joe Taylor last night at the Fair Lawn ARC Club Meeting on FT8 & Beyond an introduction to FT4.

Click here to view on YouTube.

Thank you for the tip, Pete!  FT4 looks like a fascinating iteration of the popular FT8 mode.

Post Readers: Any fans of FT8 out there?

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“Slow Scan Radio” is a new digital program on Channel 292

(Source: Southgate ARC via Mike Hansgen)

New Datamodes programme on BC bands

Starting on Wednesday 25th of July 2018 at 1830 UTC, there will be a new 30 minute programme featuring various datamodes, such as SSTV and some of the more complex and interesting PSK modes.

The programme is called ‘SLOW SCAN RADIO’, and will go out on 6070 kHz AM via the transmitter of German based relay station Channel 292, and should be audible throughout many parts of Europe.

http://www.channel292.de/schedule-for-bookings/

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Video: Professor Joe Taylor K1JT talks FT-8 and WSJT-X

(Source: Southgate ARC)

Work the World with WSJT-X

Video of the talk given by Professor Joe Taylor K1JT about the FT-8 and WSPR modes at the 2018 MicroHAMS Digital Conference on March 24

Budd Churchward WB7FHC writes:

Dr. Joe Taylor, K1JT, author of many of the weak signal digital modes and co-author of the very popular FT-8 mode presented: “Work the World with WSJT-X”  at the 2018 MicroHAMS Digital Conference in Redmond, Washington about the WSJT-X Digital Software Suite for Amatuer Radio.

Dr. Taylor gives a detailed description of both the FT-8 and WSPR modes that so may Hams are using all over the world.

Watch Work the World with WSJT-X – Dr. Joe Taylor

Click here to view on YouTube.

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