Tag Archives: Utility

Patrizio seeks information about mystery signals he’s discovering across the HF bands

Many thanks to SWLing Post contributor, Patrizio Cardelli, who has discovered some interesting signals on the HF bands and is seeking information about them.

A little background: Patrizio asked me about these signals a few weeks ago and based on a quick glance at the spectrum and waterfall images I assumed it was DRM (Digital Radio Mondiale). I was wrong, of course. Had I looked at the actual frequency and bandwidth, I would have immediately realized is was not DRM. My email load has been so heavy as of late, and my time to reply at such a premium, I rushed through the reply–my apologies, Patrizio!

Patrizio followed up with this message:

Hello Thomas,

I hope this message finds you well. I wanted to share my recent radio exploration based on your advice. I followed your suggestion and investigated a sample signal within the 60-meter band, specifically settling on the one at 4.962 kHz.

I attempted to decode it using the Dream software but encountered no success. It seems this isn’t a Digital Radio Mondiale (DRM) transmission. To rule out local QRM (interference), I tested various Kiwi SDR receivers across Europe, both to the south and north of my QTH. Interestingly, I managed to pick up this signal everywhere, with a stronger intensity noted in the northern locations.

I’m eager to publish this article to find out if other Shortwave Listeners (SWL) have been able to decode this transmission. Additionally, I’d like to mention that similar signals, either continuous or intermittent, are present on various HF frequencies.

I look forward to any insights or experiences others in the community might have regarding this intriguing signal.

Audio sample:

While I recognize these signals now, and I’m sure most of you who cruise the bands have seen/heard these as well, Patrizio is a relatively new SWL, turns out, and I thought it might be fun exploring just what these signals are. 

Readers: If you know what these signals are, please comment. Indeed, I’m sure there are a number of SWLing Post readers who have hands-on time with generating these signals as well in a past life or current career. Let’s explore!

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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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Guest Post: Why listen to shortwave radio?

Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:


Why listen to shortwave radio?

By Jock Elliott, KB2GOM

Decades ago, an entrepreneur challenged his audience with a concept of critical importance: “Every once in a vhile, it is important to ask ourselves vhy are we in business?” He had a waaay cool Austrian accent, and his point was valid: every once in a while, we should examine our fundamentals.

So why, indeed, listen to shortwave radio?

For me, the short answer is: because there are treasures out there on the shortwave spectrum, that’s why. Further, with a relatively inexpensive shortwave receiver (even better if you have a receiver with single-sideband – SSB – capability), you hear them too. You can discover things that you are unlikely to find anywhere else, and not only are they fun to hear, they are also fun to find.

So let me present for your approval a shortwave journey that I took on October 24, 2021.

1115Z – It all starts when I am flipping through my old shortwave reference materials, and a copy of a page from Popular Communications magazine, April, 1986, catches my eye: “Handy Ute Finder by Hubble Gardiner, KNE0JX.” Utes are utility stations (as opposed to hams or international broadcasters), like ships at sea, planes in the air, and fixed commercial and military stations, and the like. The article presented places to look in the HF radio spectrum between 4000 kHz and 26960 kHz, for utility stations transmitting in SSB, CW, and RTTY/ARQ modes. Is this chart still valid? I don’t know, but since I enjoy hearing people doing their jobs on the air, why not start tuning from 4000 kHz in upper sideband and see what I can hear? Freeing the Tecsun PL-880 from its case, I extend the antenna, press the power button, punch in 4000 kHz, and start turning the dial. And while my initial impulse was to discover some “utes,” I am open to whatever comes through the headphones.

1128Z, 4426 kHz USB – a ute, super loud and clear, a weather forecast from the US Coast Guard Communications Command, including a forecast of tropical weather from the National Hurricane Center. If I were a mariner, I would be pleased to hear this forecast.

Duties call, and my cruise of the bands is interrupted, to be continued later in the day . . .

2130Z, 7490 kHz AM, — highly unusual music that sounds like a mash-up between 1930s movie music and oompah bands. It’s odd but pleasant and certainly not anything you are going to hear on the “regular” broadcast stations. Turns out it is a program called Marion’s Attic on WBCQ from Monticello, Maine. Two females, Marion (with a high squeaky voice) and Christine, play recordings from yesteryear (including wax cylinders, I think). Evidently, this program has been on the air for 22 years, and it made me smile.

2150Z, 8950 kHz USB, — a ute, European weather conditions for aviators from Shannon VOLMET, Ireland, very difficult to hear on the PL880’s whip antenna, but fully copyable on my Satellit 800 with wire antenna. How cool to hear weather from all the way across the pond!

2206Z, 9350 kHz AM, (back on the PL880) — USA Radio News on WWCR, then Owen Shroyer and a Dr. Bartlett discussing the problem of a hospital in Texas apparently putting plastic bags on the heads of covid patients. Unusual, I think, but I had heard enough about the virus of late and continue to rotate the tuning knob.

2215Z, 9395 kHz AM, — My ears are tickled by cool jazz, a very together group, laying it down with style. “This is cool jazz, jazz from the left coast,” the announcer intones as he cues up another group. It’s WRMI, transmitting from Okeechobee. Hearing it, I flashed back to “The Hawthorn Den, Jazz after Midnight” Saturday nights, listening under the covers when I was a kid.

2226Z, 9830 kHz, Voice of Turkey, in English — A professor presents an analysis of the United Nations, which he thinks needs to be reformed due to the shifting of the axes of power. This is followed by exotic music with nice female singer.

2239Z, 9955 kHz,WRMI, — Glen Hauser hosts The World of Radio, detailing the status of various shortwave stations around the world. Fascinating stuff and well worth the time.

2257Z, 10051 kHz USB, — a ute, weather for aviators again, but this time from Gander, Newfoundland. Makes me glad to be in a nice warm house.

So that’s what a little over an hour of turning the knob yielded, and that’s why to listen to shortwave radio: because you never know what you may encounter. Who knows what you might discover with a shortwave radio and a little wandering around?

Remember what Gandalf said: “Not all who wander are lost.

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CPRM Lisboa: Another mystery signal solved

In response to our latest mystery utility signal challenge, SWLing Post contributor, Dean Bianco replies:

This is the musical marker for CPRM Lisboa, a radiotelephone terminal that provided overseas telephone and telegraph communications in the days prior to satellites.

I remembered the non-broadcast HF frequencies being loaded to bursting with many of these radio services. When not scrambled for privacy, one could hear a telephone call in progress. Instead of a musical IS such as this one, most were loop tape voice ID’s in several languages (almost always including English). So naturally these musical loops made it quite difficult to know what exactly one was hearing, to say the least!

To verify check out the following embedded audio file made by Willi Passmann  (via the excellent UtilityRadio.com website):

Once again, thanks to Dean Bianco for solving yet another mystery! Obviously, Dean is a Black Belt SWL and DXer!

FYI: I’ve received a number of emails from readers who really enjoy these mystery signals. Since we all seem to have more time at home these days, I’ll plan to keep them coming!


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VE7SL explores DXing the utilities

Photo: US Coast Guard

Many thanks to SWLing Post contributor, Eric McFadden (WD8RIF), who shares a link to this excellent article by Steve (VE7SL) where he explores his success DXing utility stations on shortwave:

(Source: VE7SL)

DXing The Utilities (Part 1)

After building the house here on Mayne Island, in the early 90’s, it was several years until I was able to set up a dedicated station. In the meantime, I limited my radio activities strictly to listening. I had a nice Icom R-71A set up in a hall closet and spent my radio-time, mostly on weekend evenings, listening to maritime CW, HF aeronautical traffic and, of course, NDBs below the broadcast band.

My HF receiving antenna consisted of three inverted-V’s … one for 160m, the second for 80m and the third for 40m … all fed from the same coaxial line at the top of a 70′ Balsam. It didn’t take long to realize what an exceptional radio location I had, living right at the edge of the ocean, with dozens of miles of saltwater in most directions other than due west.

I really enjoyed following evening airline flights across both the North and South Atlantic, and in the early winter afternoons, following the commercial air-traffic all over Africa. Even though listening on 5 or 6MHz, I was amazed at how strong the signals from airliners over Africa at 30,000 feet or more could become, this far to the west. In the early mornings, directions were reversed and traffic from the far east, right into India, was fairly common. Often, small single-engine planes, usually run by various missionaries, could be heard while on the ground, taxiing at remote field locations and calling in via HF radio to request takeoff and flight-following.

Now QSL’s have always been one of my top radio interests and it wasn’t long before I started sending and collecting verifications for both the aircraft and the ships I was hearing … once I had figured out how to get my reception reports to their proper destinations.[…]

Click here to continue reading Part 1 of “DXing the Utilities.”

Click here to read Part 2.

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Marine Weather Center daily weather reports on shortwave

Sail Boat Yacht On Sea

Many thanks to SWLing Post contributor, Al Holt, who writes:

Your readers may be interested in tuning in the daily (except Sunday) broadcasts of Marine Weather Center on 4045 and possibly 8173, 12,350 kHz. These broadcasts use upper sideband mode. https://www.mwxc.com/index.php

It’s described as, “custom weather and routing information for small vessels in the Caribbean Sea, Bahamas and United States East Coast,” and is based near Lakeland, FL.

As a subscription weather service for pleasure craft, but they provide an interesting roundup and forecast of weather in this area of the world. They do take questions and traffic from subscribing vessels at the conclusion of their broadcast.

I am usually am able to receive the omnidirectional broadcast on 4045 kHz here in northern Florida. But, their coverage at greater distances is pretty good I think.

The chart below (taken from their ‘Services’ page https://www.mwxc.com/marine_weather_services.php ) shows this broadcast starting at 1100z, but I usually hear them closer to 1200z and that may be due to atmospheric conditions. I haven’t had much success catching their later transmissions. I’m not sure how often their webpage gets updated and schedule changes are probably relayed privately to their subscribers.

Wow!  Thank you so much for sharing this information, Al.

Post Readers: I know there are a number of SWLing Post readers who sail and cruise (some on very long voyages)—I’m curious if any use the Marine Weather Service regularity. Please comment!

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Reuters: Cyber threats prompt return of radio for ship navigation

eLoran (Image Source: UrsaNav)

(Source: Reuters via Ken Hansen and Dan Hawkins)

LONDON (Reuters) – The risk of cyber attacks targeting ships’ satellite navigation is pushing nations to delve back through history and develop back-up systems with roots in World War Two radio technology.

Ships use GPS (Global Positioning System) and other similar devices that rely on sending and receiving satellite signals, which many experts say are vulnerable to jamming by hackers.

About 90 percent of world trade is transported by sea and the stakes are high in increasingly crowded shipping lanes. Unlike aircraft, ships lack a back-up navigation system and if their GPS ceases to function, they risk running aground or colliding with other vessels.

South Korea is developing an alternative system using an earth-based navigation technology known as eLoran, while the United States is planning to follow suit. Britain and Russia have also explored adopting versions of the technology, which works on radio signals.

Continue reading at Reuters online…

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