Iqaluit's Navtex signals

[GB46]

I've been picking up a Navtex signal lately from Iqaluit Radio every night at about 04:25 UTC on 8416.5 kHz. Prior to that, the frequency is usually used for USCG navigational bulletins, especially from San Francisco. When those bulletins are finished, the signal doesn't go off the air, but seems to just idle as if to guard the frequency. When Iqaluit comes on later they send what look like aviation metar reports, judging by the abbreviations. There are frequent references to Baffin Island in the Canadian arctic (north of Iqaluit, the capital of Nunavut). Ice-covered areas are mentioned, too.

Unfortunately the signal fades rapidly in and out, causing MultiPSK to lose synchronization quite often. I usually tune them in on my R75, and find that using CW reverse mode with a narrow filter works best. However, I'm also able to pick them up and decode them on my ATS-909X with just the whip antenna.

Has anyone else heard Iqaluit Radio on that frequency?

 

[ka3jjz]

A very quick check of the UDXF shows the answer is yes - one log was 2 khz off, but that may have been someone making a tuning error.

You can easily search the UDXF logs if you are a member (hint hint), and the result would be

https://groups.io/g/UDXF/search?q=8416.5

https://groups.io/g/UDXF/search?q=Iqaluit+Radio

There are several other stations on that frequency, as shown here (may not be complete)..From our DXing Digital Utilities article...

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

Mike

 

[ka3jjz]

For those that might be curiouse - MultiPSK isn't the only package that can cover NAVTEX (as SITOR-B, on which protocol it's based)...see this link for more.;..

https://www.sigidwiki.com/wiki/SITOR-B

Mike

 

[GB46]

There are several other stations on that frequency, as shown here (may not be complete)..From our DXing Digital Utilities article...

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

Mike

Thanks, Mike. Actually, I had already noticed many of the other stations that use that frequency in the EiBi shortwave schedule, and a few days ago I saved the above list from dxinfocentre.com as a PDF for offline reference.

BTW, the only way I can successfully decode those stations with the receiver tuned exactly to 8416.5 is by using the R75's reverse CW mode. Both USB and LSB put me too far off the audio frequency. With the ATS-909X I can get the equivalent at 8415 in USB mode, after fiddling with the fine tuning a bit. Unfortunately the portable doesn't display the resulting frequency after fine tuning is used. The same is true for my old Sony ICF-2002. That one is even more of a fiddle, because the HF tuning step is always a whopping 5 kHz, and the fine tuning thumbwheel is really awkward to use. I guess this is one of the drawbacks of portables.

 

[ka3jjz]

Yes unfortunately the implementation of how to tune sideband - important when fooling around with digital - really does vary from one model to the next. A little fiddling is to be expected.

Mike