Navtex freeware

[GB46]

Lately I only use MultiPSK to decode Navtex messages, and have been frustrated by its slow loading and crowded UI. Today I went looking for a freeware replacement, and happened on a program aptly named Navtex.exe. It does just that: Decodes Navtex very well through the computer's soundcard, has no transmit options, so its layout is nice and clean. I found it at www.frisnit.com. The only drawback is the lack of a font size option, but the log, which is saved automatically, is in plain text format and can be read in any text editor.

I didn't have to use the installer; just opened it as a Zip archive and extracted Navtex.exe. The strange thing is that if I drag the splitter between the two panes of the program, that's remembered between sessions, but I can't find its configuration file anywhere on my system. It's not in the registry, either. Here's what the program looks like:

 

[ka3jjz]

Yes we have that one in our software decoders wiki, among several others. Nice clean looking UI there. Should be good for folks that are just looking for a NAVTEX decoder without anything else...Mike

 

[ka3jjz]

Here's a few more NAVTEX decoders, though not all freeware, it does show a range of software available;

Smartcom Software

Software and systems for mobile communications and navigation systems

www.smartcomsoftware.co.uk

The NDB List Datamodes Section
(go about 2/3 way down for YAND or Yet Another Navtex Deocder). YAND is also quite popular. Another source can be found here;:

Amateur Radio "Digital" Software

Amateur Radio Digital Software

nl9222.home.xs4all.nl

Decode NAVTEX Weather Transmissions With Your Android Device

Decode NAVTEX Weather Transmissions With Your Android Device

www.blackcatsystems.com

Not as up to date as one would like, but still a decent reference for NAVTEX broadcasts

http://www.dxinfocentre.com/navtex.htm

And of course, check things like the UDXF and the Longwave Club of America for more up to date NAVTEX info.

Mike

 

[ka3jjz]

I knew I forgot one - again, not freeware, but another platform that can decode NAVTEX...

Decode NAVTEX Weather Transmissions With Your iPhone and iPad

Decode NAVTEX Weather Transmissions With Your iPhone and iPad

www.blackcatsystems.com

So as you can see, there is a number of apps for different platforms....Mike

 

[ka3jjz]

How about one for Java?

JNX

Mike

 

[GB46]

Yes we have that one in our software decoders wiki, among several others. Nice clean looking UI there. Should be good for folks that are just looking for a NAVTEX decoder without anything else...Mike

Still looking for that configuration data. The options I set through the checkboxes are also remembered. I've gone through all the possible folders and subfolders that keep such files with my hidden and system files visible, and haven't found anything related to Navtex.exe. Scoured the registry, too. I did have a program once that actually wrote the user's config data directly into the .exe file, but that was indicated in the file's modified date, which is not the case here.

 

[GB46]

How about one for Java?

JNX

Looks good! The one at Frisnit.com also offers a Java version, but I don't have Java support, so I can't test it.

 

[eorange]

Here's NAVTEX I decoded tonight using a Yaesu VR-500, a homebrew loop, and MultiPSK which is still my favorite package. The loop was 4 feet away from the laptop which isn't ideal, but nonetheless the decode was pretty good:

ORCE EINDS SXISTS ITHIH A AWTP OOT RADIUS AROUND THESE HELICOPTER
SUFFICIENT TO BLOW PEOPLE AND OBJECTS FROM EXPOSED DECKS AND
CAPSIZE SMALL CRAFT. T TOWED DEVICES MAY B COMPLETELY INVISIBLE
AND INCLUDE LARGE CABLES AND OBJECTS ON_OR JUST BEBOW THE SURFACE,
STREAMANG UP TO 1,200 FT BEHIND THE AIRCRAFTFMMTO MINIMIZE THE
POTENTIAL FOR MISHAP, MAMINIRS ARA _EQ0ESTED TO REMAIN WELL CLEARA
OF THESE DANGNR ZONES WHEN MCM OPERATIONS ARE ENCOUNTERED.
3. FOR SECTOROVA AND NCNNNBR_ZHZZ__ UNTIL CANCELLED.
4. CA_D_PXX

 

[spongella]

YaND is another great program, been using it many years. You can leave it running overnight and read all the messages next morning.

 

[eorange]

I've also used YaND and it's very good software. But I'm so accustomed to using MultiPSK that I usually fire that one up first.

 

[GB46]

Here's NAVTEX I decoded tonight using a Yaesu VR-500, a homebrew loop, and MultiPSK which is still my favorite package. The loop was 4 feet away from the laptop which isn't ideal, but nonetheless the decode was pretty good:

ORCE EINDS SXISTS ITHIH A AWTP OOT RADIUS AROUND THESE HELICOPTER
SUFFICIENT TO BLOW PEOPLE AND OBJECTS FROM EXPOSED DECKS AND
CAPSIZE SMALL CRAFT. T TOWED DEVICES MAY B COMPLETELY INVISIBLE
AND INCLUDE LARGE CABLES AND OBJECTS ON_OR JUST BEBOW THE SURFACE,
STREAMANG UP TO 1,200 FT BEHIND THE AIRCRAFTFMMTO MINIMIZE THE
POTENTIAL FOR MISHAP, MAMINIRS ARA _EQ0ESTED TO REMAIN WELL CLEARA
OF THESE DANGNR ZONES WHEN MCM OPERATIONS ARE ENCOUNTERED.
3. FOR SECTOROVA AND NCNNNBR_ZHZZ__ UNTIL CANCELLED.
4. CA_D_PXX

What station was that from, and on what frequency? I receive very little Navtex here except for the regular evening USCG broadcasts on 8416.5 kHz. They usually come in strong enough to overcome the RFI from my laptop, and the text is quite readable.

What I like about Frisnit.com's decoder is that it loads in an instant and automatically organizes the incoming messages into separate lists by category, e.g. marine weather forecasts, navigational warnings, etc. Lately the messages have contained lots of warnings about space debris out in the Pacific, rocket launches and underwater detonations. A few weeks ago they reported that a distress signal had been received from a ship off the Panama coast. That was probably one of those cruise ships that had COVID-19 aboard and wasn't allowed to enter the Panama Canal.

MultiPSK is very good, but takes an awful long time to start on my computer. It also has too many transmitting features that I can't use, since I'm not a ham; they take up too much screen space, I've noticed that sometimes it momentarily shows the French version on starting up until the app is fully loaded; then the English version replaces it.

 

[eorange]

This was around 02:50 UTC on 518 kHz, so likely Norfolk, VA. You know, I never tried 8416.5 kHz...will try tonight, thanks!

I never ran the frisnit decoder, will give that a try too. I had been to frisnit before, poring over the pac-man disassembly

 

[GB46]

This was around 02:50 UTC on 518 kHz, so likely Norfolk, VA. You know, I never tried 8416.5 kHz...will try tonight, thanks!

That's a standard Navtex frequency, but I can't monitor longwave here, as the RFI from power lines in my neighborhood is very intense below the HF range. Even the AM broadcast band is difficult. As soon as I tune higher than 2.5 mHz or so, I leave a lot of that noise behind.

My laptop also interferes with the lower frequencies in an odd way. It blanks out the AM band almost entirely, unless I place the portable farther away from the laptop. If I put the laptop into sleep mode, I can then listen to the AM band with the radio closer, but get a background noise similar to the rise and fall of a siren; this is from the laptop, and timed perfectly with the rhythmic flashing of the sleep mode LED. This is stronger on longwave, which rules out monitoring that band altogether. I don't use my R75 on the MW and LF bands, as it doesn't have an internal ferrite loop antenna, and I don't have a long enough external antenna for those bands.

The version of Frisnit's Navtex decoder I'm using is an older one, 1.0.0.1, which seems to work better on my system than the newer versions. At any rate, its so-called "smart tune" feature is great, as it can find the signal and lock onto it very quickly, even if the radio isn't quite dead on frequency. I've seen it move down to the signal from as far away as 1500 hz. Unlike MultiPSK, you don't have to click on the right peak, either, just center the cursor over the signal.

 

[ka3jjz]

Off topic, but are you using a loop outdoors? You might be able to get away from that noise, at least somewhat....Mike

 

[GB46]

Off topic, but are you using a loop outdoors? You might be able to get away from that noise, at least somewhat....Mike

No, Mike. Everything's inside in this apartment, but even without the computer RFI, I'd likely encounter more from the power lines at the front of this building if I set up an outside antenna on the balcony. This street carries a main line serving several other locations in the city, and there's also a branch circuit running down the side street next to us at right angles to the main one.

Looks like the only way I could significantly reduce the RFI is by moving to a detached house in a rural location, or maybe on a mountain top. That's in fact what the announcer at RHC once remarked when he read my signal report aloud on the Mailbag show. He said "Gerry, you'll just have to move!"

Not justifiable for this hobby, considering the poor propagation these days.

 

[spongella]

Near the NAVTEX frequency (518 kHz) you may hear a Canadian beacon, YWA, id'ing in slow Morse code.

 

[GB46]

Near the NAVTEX frequency (518 kHz) you may hear a Canadian beacon, YWA, id'ing in slow Morse code.

That's in Ontario, so I won't hear it. Even CHU on 7850 kHz comes in weak here. We're in the BC interior and blocked by mountain ranges to the east of us, so it's no surprise. The only longwave signals I've heard so far are te CW identifiers of NDBs in my area.

 

[eorange]

Last night I did a test. Around 10:30pm EDT I began getting a strong NAVTEX signal on 518 kHz.

- MultiPSK provided a very solid decode.

- frisnit NAVTEX never decoded anything. I saw the waveform, but tried FEC on/off, didn't matter, just random characters.

- YanD -> help? I last used it a year ago and remember it working. I fired it up last night and only saw the spectrum display. But there were no tabs (log, NAVTEX schedule, nothing). So I couldn't actually see if there were any messages. Any idea why this was?

 

[ka3jjz]

How are you routing your audio? If you are using a SDR did you point the app's input to your VAC output? Mike

 

[eorange]

No SDR. Radio audio out to USB soundcard in. Old school, baby!