{"id":16890,"date":"2016-01-19T07:59:53","date_gmt":"2016-01-19T11:59:53","guid":{"rendered":"http:\/\/swling.com\/blog\/?p=16890"},"modified":"2016-01-19T07:59:53","modified_gmt":"2016-01-19T11:59:53","slug":"how-to-decode-maritime-broadcasts-in-rtty-sitor-b-and-navtex","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2016\/01\/how-to-decode-maritime-broadcasts-in-rtty-sitor-b-and-navtex\/","title":{"rendered":"How to decode maritime broadcasts in RTTY, Sitor B, and NAVTEX"},"content":{"rendered":"
\"(Photo

(Photo Credit: NOAA)<\/p><\/div>\n

Many thanks to SWLing Post contributor, Mario\u00a0Filippi (N2HUN) for the following guest post:<\/em><\/p>\n

\n

Maritime Broadcasts in RTTY, Sitor B, and NAVTEX.<\/h1>\n

By Mario Filippi, N2HUN<\/strong><\/p>\n

(All photos below are courtesy of the author. Click each image to enlarge.)<\/em><\/p>\n

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\u2019s strong signal.<\/p>\n

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 (R<\/em><\/strong>adioT<\/u><\/strong>eleTY<\/u><\/strong>pe) parameters used by WLO transmissions are 45.45 bauds, 170Hz shift. These are most commonly used by amateur radio ops too. If you\u2019ve roamed the bands for RTTY signals you\u2019ll find that most are encrypted with a few exceptions, one of which is WLO which is transmitting continuously.<\/p>\n

\"Tabletop

Tabletop SW radio set to WLO; SignaLink USB links radio to computer for decoding.<\/p><\/div>\n

On 8.472 MHz you\u2019ll 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.<\/p>\n

To decode RTTY signals you\u2019ll need a shortwave receiver with a BFO (Beat Frequency Oscillator), a way to pipe your radio\u2019s audio into your computer\u2019s 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<\/a> . 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.<\/p>\n

\"MMTTY

MMTTY dashboard with WX info. Cross-like indicator on upper right aids in tuning signal.<\/p><\/div>\n

Another software available for decoding RTTY is Fldigi.<\/a> Again, you\u2019ll 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\u2019ll see Fldigi doing it\u2019s thing as shown below. Both MMTTY and Fldigi have waterfalls displaying a visual image of the received signal. With practice you\u2019ll be able to distinguish the different common RTTY shifts just by looking at the waterfall.<\/p>\n

\"Fldigi

Fldigi in action with split screen; RTTY text above, waterfall below.<\/p><\/div>\n

Now to Sitor B (Si<\/u><\/strong>mplex T<\/u><\/strong>eletype O<\/u><\/strong>ver R<\/u><\/strong>adio 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 \u2018Net as free downloads. One is MultiPSK<\/a>, the other is YaND<\/a>.<\/p>\n

I like YaND (Y<\/u><\/strong>et a<\/u><\/strong>nother N<\/u><\/strong>avtex D<\/u><\/strong>ecoder) 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.<\/p>\n

\"WLO

WLO HF WX broadcast for NE Gulf on 1\/18\/16 .<\/p><\/div>\n

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.<\/p>\n

\"German

German RTTY station with message loop. Deciphered via MultiPSK.<\/p><\/div>\n

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\u2019ll be able to receive these transmissions, but remember you\u2019re 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!<\/p>\n

\"YaND

YaND NAVTEX schedule for various NAVAREAS.<\/p><\/div>\n

\"NAVTEX

NAVTEX on 518 KHz from station VAR-9, New Brunswick, CAN. Messages begin with \u201cZCZC.<\/p><\/div>\n

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<\/a>.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Many thanks to SWLing Post contributor, Mario\u00a0Filippi (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 […]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1114,3194,545,627,2436,3,43,1113],"tags":[4114,4683,4682,4684,4311,4681,4679,1075,4680,4678],"class_list":["post-16890","post","type-post","status-publish","format-standard","hentry","category-digital-modes","category-guest-posts","category-ham-radio","category-how-to","category-longwave","category-news","category-shortwave-radio","category-tutorials","tag-digital-modes","tag-how-to-decode-navtex","tag-how-to-decode-rtty","tag-how-to-decode-sitor-b","tag-mario-filippi-n2hun","tag-maritime-broadcasts","tag-navtex","tag-rtty","tag-signalink-usb","tag-sitor-b"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-4oq","jetpack-related-posts":[{"id":18490,"url":"https:\/\/swling.com\/blog\/2016\/04\/guest-post-tracking-high-seas-pirates-on-shortwave-radio\/","url_meta":{"origin":16890,"position":0},"title":"Guest Post: Tracking High Seas Pirates on Shortwave Radio","author":"Thomas","date":"April 23, 2016","format":false,"excerpt":"Many thanks to SWLing Post contributor, Mario Filippi (N2HUN) for the following guest post: Tracking High Seas Pirates on Shortwave Radio by\u00a0Mario 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\u2026","rel":"","context":"In "Digital Modes"","block_context":{"text":"Digital Modes","link":"https:\/\/swling.com\/blog\/category\/digital-modes\/"},"img":{"alt_text":"Suspected pirates surrender to crew members of the CGC Boutwell. (U.S. Coast Guard photo)","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/04\/Pirates-CoastGuard.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/04\/Pirates-CoastGuard.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/04\/Pirates-CoastGuard.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":41771,"url":"https:\/\/swling.com\/blog\/2020\/01\/mike-ladds-primer-on-decoding-navtex-using-an-sdrplay-sdr-with-sdruno\/","url_meta":{"origin":16890,"position":1},"title":"Mike Ladd’s primer on decoding NAVTEX using an SDRplay SDR with SDRuno","author":"Thomas","date":"January 28, 2020","format":false,"excerpt":"Many thanks to\u00a0SWLing Post\u00a0contributor, Mike Ladd with\u00a0SDRplay, who shares the following PDF primer on decoding NAVTEX with an RSP series SDR. Click here to download \"Basics to decoding NAVTEX using an RSP and SDRuno\" (PDF). Thanks for sharing this excellent guide, Mike.\u00a0 Without a doubt, SDRplay has some of the\u2026","rel":"","context":"In "Ham Radio"","block_context":{"text":"Ham Radio","link":"https:\/\/swling.com\/blog\/category\/ham-radio\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/01\/RSP-NAVTEX.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/01\/RSP-NAVTEX.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/01\/RSP-NAVTEX.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/01\/RSP-NAVTEX.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":54246,"url":"https:\/\/swling.com\/blog\/2022\/10\/mario-shares-a-short-review-of-the-airspy-hf-discovery\/","url_meta":{"origin":16890,"position":2},"title":"Mario shares a short review of the Airspy HF+ Discovery SDR","author":"Thomas","date":"October 9, 2022","format":false,"excerpt":"Many thanks to SWLing Post contributor, Mario Filippi (N2HUN), who shares the following guest post: A Short Review of the Airspy HF+ Discovery SDR by Mario Filippi (N2HUN) I recently purchased an AirSpy HF+ Discovery.\u00a0 As a SWL for over 60 years who\u2019s owned many shortwave radios by manufacturers such\u2026","rel":"","context":"In "Articles"","block_context":{"text":"Articles","link":"https:\/\/swling.com\/blog\/category\/articles\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/10\/20221005Airspy-HF_-Discovery-SDR-Mario.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/10\/20221005Airspy-HF_-Discovery-SDR-Mario.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/10\/20221005Airspy-HF_-Discovery-SDR-Mario.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/10\/20221005Airspy-HF_-Discovery-SDR-Mario.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/10\/20221005Airspy-HF_-Discovery-SDR-Mario.jpeg?resize=1050%2C600&ssl=1 3x"},"classes":[]},{"id":40685,"url":"https:\/\/swling.com\/blog\/2019\/11\/coast-guard-considers-dropping-radio-based-navtex-system\/","url_meta":{"origin":16890,"position":3},"title":"Coast Guard considers dropping radio-based NAVTEX system","author":"Thomas","date":"November 19, 2019","format":false,"excerpt":"Many thanks to\u00a0SWLing Post contributor, Tracy Wood, who shares the following article from Alaska Public Media: For decades, the Coast Guard\u2019s NAVTEX towers have broadcast from Cape Cod to Kodiak Island. The global system broadcasts weather and safety information to boats large and small. The International Maritime Organization developed the\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/10\/Ship-Marine-Maritime-Boat-knut-troim-via-unsplash.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/10\/Ship-Marine-Maritime-Boat-knut-troim-via-unsplash.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/10\/Ship-Marine-Maritime-Boat-knut-troim-via-unsplash.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/10\/Ship-Marine-Maritime-Boat-knut-troim-via-unsplash.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":16566,"url":"https:\/\/swling.com\/blog\/2016\/01\/a-review-of-the-aor-ar-3000a-wideband-receiver\/","url_meta":{"origin":16890,"position":4},"title":"A review of the AOR AR-3000A Wideband Receiver","author":"Thomas","date":"January 4, 2016","format":false,"excerpt":"Many thanks to SWLing Post contributor, Mario\u00a0Filippi (N2HUN) for the following review: The AOR AR-3000A Wideband Receiver by\u00a0Mario\u00a0Filippi, N2HUN (All photos below by author) The AOR AR-3000A is a wideband communications receiver, made in Japan, covering 100KHz \u2013 2.036 GHz with all popular modes including AM, NFM, WFM, CW, USB\u2026","rel":"","context":"In "FM"","block_context":{"text":"FM","link":"https:\/\/swling.com\/blog\/category\/fm\/"},"img":{"alt_text":"ar3000Alrg","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/01\/ar3000Alrg.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/01\/ar3000Alrg.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/01\/ar3000Alrg.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":13016,"url":"https:\/\/swling.com\/blog\/2015\/04\/practice-your-rtty-with-itty\/","url_meta":{"origin":16890,"position":5},"title":"Practice your RTTY with ITTY","author":"Thomas","date":"April 22, 2015","format":false,"excerpt":"SWLing Post reader,\u00a0George (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\u2026","rel":"","context":"In "Digital Modes"","block_context":{"text":"Digital Modes","link":"https:\/\/swling.com\/blog\/category\/digital-modes\/"},"img":{"alt_text":"ITTY","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/04\/ITTY.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/04\/ITTY.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/04\/ITTY.jpg?resize=525%2C300 1.5x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/16890","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/comments?post=16890"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/16890\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=16890"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=16890"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=16890"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}