Tag Archives: RTTY

Carlos seeks help identifying signals

Many thanks to SWLing Post contributor, Carlos Latuff, who writes:

Attached are two different recordings.
Both made in South Brazil.

– Florianópolis, 26/11/2019, 19h13 (Brasilia time) 12015 kHz

– Porto Alegre, 12/12/2019, 20h11 (Brasilia time) 7455 kHz

Searching on the Web I found these two frequencies related to US Navy NATO RTTY station STANAG 4481:

Are you able to confirm this?

Thanks for your inquiry, Carlos! Unfortunately, I cannot confirm this. If your radio had been in SSB mode, it would have made the RTTY pop out and we could have perhaps confirmed at least the RTTY mode with FLDIGI. I’m hoping a savvy SWLing Post reader can help you ID these transmissions. Please comment!

Spread the radio love

Guest Post: Tracking High Seas Pirates on Shortwave Radio

Suspected pirates surrender to crew members of the CGC Boutwell. (U.S. Coast Guard photo)

Suspected pirates surrender to crew members of the CGC Boutwell. (U.S. Coast Guard photo)

Many thanks to SWLing Post contributor, Mario Filippi (N2HUN) for the following guest post:


Tracking High Seas Pirates on Shortwave Radio

by Mario Filippi (N2HUN)

(All photos taken by author–click to enlarge)

Ahoy! After spinning a radio dial for over a half-century, shortwave listening still provides a source of adventure and interesting intercepts. While major broadcasters continue to move to the Internet and dwindle in number, there nonetheless remains plenty of utility intrigue to be had; you just need to know where to look, and be comfortable with other modes of communication such as RTTY (Radioteletype).

RTTY remains on HF (3 – 30 MHz), albeit mostly encrypted, but there are some stalwarts of this mode that transmit important and interesting information for ships at sea. The information can take the form of weather broadcasts, hazards to navigation, information on ships lost at sea, and pirate activity. Yes, pirate activity but not radio pirates; real honest-to-goodness modern day pirates looking to loot, plunder and prey upon commercial ships making an honest living or other leisure watercraft just out having fun.

SignaLink-AOR

Who knows what dangers lurk behind that dial? Trusty AOR AR-3000 receiver and SignaLink™.

Has your interest been piqued? When avast mateys as I spin ya’ a yarn on how to find out where these sea-faring scoundrels lurk from the Caribbean all the way to the South China sea!

Pirate activity is not something of the past; it exists today and is a threat conducted by ragtag armed ragamuffin groups. To keep abreast of the action you’ll need the following gear: a shortwave radio with single sideband (SSB), a decent antenna, a means of decoding RTTY, and WLO, a station from Mobile, AL that transmits information to ships at sea.

You’ll do well to add WLO’s frequency to your receiver’s memory list as it’s a pretty active station that faithfully serves the sea-faring community and is one of the gems on HF.

First, tune your receiver using USB (Upper Side Band) to around 8.472 MHz and listen for that warbling sound. You will also need a way to pipe the audio from your shortwave receiver to a computer (I use a SignaLink™ USB) and a decoding program for RTTY, such as MMTTY.

To decode you’ll need to set the baud rate (45.45) and shift (170 Hz) on MTTY (or software program of choice) and tune your radio slightly up and down frequency until the software starts decoding.

You may have to press the “Reverse” or “Rev” selector at times. MMTTY is my favorite for RTTY decoding, and a picture of it is below.

WLO, Mobile AL, with RYRY idling loop, MMTTY decoder, 45.45 bauds, 170Hz shift, “Rev.”

WLO, Mobile AL, with RYRY idling loop, MMTTY decoder, 45.45 bauds, 170Hz shift, “Rev.”

MMTTY is available as a free download from Makato Mori, JE3HHT. I’ve used his program for over a decade and it performs well.

You can also use MultiPSK or FLdigi to decode RTTY so it’s the user’s choice as to which is a better fit.

Anyway, what are these pirates up to? Well the next few screenshots (click to enlarge) show some interesting activity as per WLO’s RTTY transmissions:

Pirates use element of surprise with guns and knives as armaments.

Pirates use element of surprise with guns and knives as armaments.

Somali pirates reportedly armed with automatic weapons and rocket-propelled grenades. Yikes!

Somali pirates reportedly armed with automatic weapons and rocket-propelled grenades. Yikes!

pic5

Give ‘em hell boys! An alert bulk carrier crew aborted hijacking with teamwork and water cannon.

Ships are encouraged to report pirate activity via FAX or phone.

Ships are encouraged to report pirate activity via FAX or phone.

Well mateys that’s enough high seas adventure for now, so first shove off to the galley for some grub (or grog) and then head to the radio room, turn on that rig and get ready for action on HF, you’ll find plenty to choose from, it’s out there for you.

I would like to thank the operators of WLO for providing such a valuable service to mariners and for providing us radio aficionados with interesting reception! And thanks readers!

P.S. Note that WLO alternates from RTTY to Sitor B so just make sure you are listening to the RTTY broadcast. If the transmission is in Sitor B then you can use a NAVTEX (e.g. YAND) decoder instead.


Thank you so much, Mario, for sharing yet another fascinating aspect of our radio world! FYI: I’m planning on purchasing a SignaLink USB at the Dayton Hamvention this year.

Readers, you can read all of Mario’s posts by clicking or bookmarking this link.

Spread the radio love

How to decode maritime broadcasts in RTTY, Sitor B, and NAVTEX

(Photo Credit: NOAA)

(Photo Credit: NOAA)

Many thanks to SWLing Post contributor, Mario Filippi (N2HUN) for the following guest post:


Maritime Broadcasts in RTTY, Sitor B, and NAVTEX.

By Mario Filippi, N2HUN

(All photos below are courtesy of the author. Click each image to enlarge.)

Non-voice high seas weather broadcasts and safety messages to mariners can be found by spinning your VFO dial to 8.472 MHz USB courtesy of WLO from Mobile, AL, which provides these transmissions continuously. Here on the East Coast it is received with regularity due to it’s strong signal.

Those of you who are neophytes to RTTY or just want to dabble then this is the place to be to try your hand at an old and venerable digital mode. The RTTY (RadioTeleTYpe) parameters used by WLO transmissions are 45.45 bauds, 170Hz shift. These are most commonly used by amateur radio ops too. If you’ve roamed the bands for RTTY signals you’ll find that most are encrypted with a few exceptions, one of which is WLO which is transmitting continuously.

Tabletop SW radio set to WLO; SignaLink USB links radio to computer for decoding.

Tabletop SW radio set to WLO; SignaLink USB links radio to computer for decoding.

On 8.472 MHz you’ll receive weather information from different latitude/longitudes, along with other pertinent information to mariners such as high seas pirates (not radio pirates!) and naval maneuver areas that are important for ships to avoid. It makes for interesting copy.

To decode RTTY signals you’ll need a shortwave receiver with a BFO (Beat Frequency Oscillator), a way to pipe your radio’s audio into your computer’s sound card, and decoding software. There are several RTTY software packages out there, free, and my favorite is MMTTY. More info on MMTTY is at: http://hamsoft.ca/pages/mmtty.php . Old timers will find this software a snap to use, but newcomers will have to fiddle with the controls to get the decoding going. Below is a snapshot of MMTTY decoding a typical weather broadcast.

MMTTY dashboard with WX info. Cross-like indicator on upper right aids in tuning signal.

MMTTY dashboard with WX info. Cross-like indicator on upper right aids in tuning signal.

Another software available for decoding RTTY is Fldigi. Again, you’ll have to input the correct RTTY parameters such as baud rate and shift into the program along with adjusting your VFO carefully. It takes practice, but when the decoding is successful you’ll see Fldigi doing it’s thing as shown below. Both MMTTY and Fldigi have waterfalls displaying a visual image of the received signal. With practice you’ll be able to distinguish the different common RTTY shifts just by looking at the waterfall.

Fldigi in action with split screen; RTTY text above, waterfall below.

Fldigi in action with split screen; RTTY text above, waterfall below.

Now to Sitor B (Simplex Teletype Over Radio Mode B), another non-voice mode we can use to decode WLO transmissions. Sitor B sounds a lot like RTTY to the human ear, but requires different decoding software. WLO transmits weather information via Sitor B immediately after RTTY transmissions, switching back and forth, which makes for even more fun! Software that decodes Sitor B is available on the ‘Net as free downloads. One is MultiPSK, the other is YaND.

I like YaND (Yet another Navtex Decoder) which is used to decode NAVTEX (Navigational Telex) transmissions commonly found on 490 KHz and 518 KHz, but it works well for decoding Sitor B. There is a difference in the way messages are processed in NAVTEX versus Sitor B and for further information perform a Google search. But the fastest and easiest way to decode Sitor B transmissions from WLO is to fire up YaND. Below is a recent NAVTEX HF broadcast capture.

WLO HF WX broadcast for NE Gulf on 1/18/16 .

WLO HF WX broadcast for NE Gulf on 1/18/16 .

Well, hopefully some of you will be inspired to check out maritime weather/safety information found on WLO using RTTY/Sitor B/NAVTEX software. However, RTTY can also be found on the ham bands and on shortwave frequencies. Several RTTY stations from Germany are found on frequencies such as 11.039MHz and 14.467MHz. Their weather information format is quite different and will give you an idea of European weather conditions and allow you to practice your German. When not sending weather info they run a RTTY message loop below at 50bauds/425Hz shift.

German RTTY station with message loop. Deciphered via MultiPSK.

German RTTY station with message loop. Deciphered via MultiPSK.

In closing, make sure to also check out the NAVTEX broadcasts found just below the AM broadcast band on 490 and 518 KHz; using YaND or MultiPSK you’ll be able to receive these transmissions, but remember you’re not on HF, you are on MW (medium wave), where signal distances are shorter and present a greater reception challenge. YaND software has a NAVTEX broadcast schedule built in as seen below; you have to identify your specific NAVAREA or navigational area, then look at the times and frequencies to determine when to listen in. My QTH is in NAVAREA 4. Lots of interesting information is passed in these NAVTEX transmissions so listen in and have fun!

YaND NAVTEX schedule for various NAVAREAS.

YaND NAVTEX schedule for various NAVAREAS.

NAVTEX on 518 KHz from station VAR-9, New Brunswick, CAN. Messages begin with “ZCZC.”

NAVTEX on 518 KHz from station VAR-9, New Brunswick, CAN. Messages begin with “ZCZC.

Mario Filippi (N2HUN), is the author of this post and a regular contributor to the SWLing Post. Click here to read Mario’s guest posts.

Spread the radio love

Practice your RTTY with ITTY

ITTY

SWLing Post reader, George (NJ3H), writes:

First off, this short message is not about listening to anything over the radio, but over the internet. So I am sure that may be a disappointment for some. However, it does give folks a chance to listen to and decode RTTY and exercise their copy of FLDigi or MMTTY.

At rtty.com, there is an application called “Teletype over the Internet (ITTY)”. Instructions are posted that allow the user to connect to the ITTY server (with WinAmp, Media Player, etc), hear teletype, and decode with you choice of decoding software.

I use Windows Media Player and FLDigi to copy the ITTY channel. As I recall, one must set “Reverse” to the on (green light) position in FLDigi.

There are folks who are continually uploading news articles (some serious – some offbeat). Instructions are included so you can upload your own news articles also.

So for times when nothing is happening on the radio or for something a little different to do, users may find this an enjoyable diversion.

Have fun and enjoy.

Many thanks, George.  Indeed, this is a great way to hone your RTTY decoding skills and build confidence in those who are new to this classic digital mode!

Click here to go to RTTY.com; the link to ITTY is found in the body of their home page.

I’ve pasted an instructional video below which gives a great overview if ITTY:

Spread the radio love

Your shortwave could have delivered the newspaper?

1938: The Gernsback Radio Newspaper (Photo: Smithsonian Magazine)

(Source: Smithsonian Magazine)

The introduction of broadcast radio caused some in the newspaper industry to fear that newspapers would soon become a thing of the past. After all, who would read the news when you could just turn on the radio for real-time updates?

Newspapers had even more to fear in 1938 when radio thought it might compete with them in the deadtree business as well.

The May, 1938 issue of Hugo Gernsback‘s Short Wave and Television magazine included an article titled “Radio to Print News Right In Your Home.” The article described a method of delivering newspapers that was being tested and (provided it didn’t interfere with regular radio broadcasts) would soon be used as a futuristic news-delivery method.

[…]This invention of a wireless fax, as it were, was credited to W.G. H. Finch and used radio spectrum that was otherwise unused during the late-night hours when most Americans were sleeping. The FCC granted a special license for these transmissions to occur between midnight and 6am, though it would seem that a noisy printing device in your house cranking away in the middle of the night might have been the fatal flaw in their system. It wasn’t exactly a fast delivery either, as the article notes that it takes “a few hours” for the machine to produce your wireless fax newspaper.

The full article, is a must-read.

Fascinating to realize that even in the infancy of wireless, newspapers already felt threatened by new technology. Goes to show that the more things change, the more they stay the same.

Spread the radio love