Tag Archives: Radiofax

Carlos captures a number of Radiofax decodes with his XHDATA D-808

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Many thanks to SWLing Post contributor, Carlos Latuff, who shares these recent Radiofax decodes on Twitter:

Hey Thomas my good man, have a look how good were the NOAA radiofax reception in Urca Beach, Rio de Janeiro, from USCG radio stations in Pt. Reyes, Boston and Honolulu:

John improves his Radiofax game!

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Earlier this week we posted a note from John who only recently took a deep dive into the world of Radiofax transmissions, inspired by Carlos Latuff‘s recent posts. 

I mentioned to John that he’ll hone his skills the more he captures these Radiofax transmissions. John just sent the following update:

Thanks, Thomas!

Indeed you are correct.

Having more luck decoding the Boston service… remembered I have a Sony AN-LP1 external antenna and so I unpacked and unraveled it and plugged in to the D-808 … drop that noise floor and…

12179kc USB Fine Tune +50

Above is the best example I have so far with HF FAX.

I guess it’s rather easy to decode these overall once you get the noise floor down, and fine tune the signal. These transmissions can take several minutes to complete which allows for a great deal of fade during that time.

Here is the original version [via the OPC Mobile Website – Atlantic]:

Radio has filled my off-hours for the best part of 50 years now. I should no longer be surprised to find something I had overlooked like this that just adds to the fun and challenge of it.

72s and 3s.

John Johnson
N8ELK

Thank you so much, John, for sharing this with us! That is a brilliant decode, indeed!

Inspired by Carlos, John dives into the world of Radiofax

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Many thanks to SWLing Post contributor, John Johnson, who writes:

Well, based on this post from Carlos Latuff–QSL: Australian Radiofax Received in Brazil–I got interested in HF weather fax decoding. I asked how to do it and got an answer but did not find a linked post that would help.

So as usual a wikipedia is helpful: WEFAX – Signal Identification Wiki

Which led me to realize… I already owned the Black Cat Systems decoder in my iPhone, but alas had never tried to use it!

So I reinstalled the HF FAX program. It had been included in a package of iPhone ham software programs I had previously purchased. I then searched the frequencies linked here: Marine Weather Broadcasts from the USCG

And soon after on 12179kc on my D-808 around Noon eastern time on 11/4/23 was decoding my first partial wx fax from Boston, I believe:

I then started fine tuning the D-808 and as you can see the fax quality began to improve significantly…

Alas the signal ended very abruptly, before I could perfectly tune it… I never received a complete fax but this was a fun radio exercise and I will keep at it.

WxFax (this is my name for it) reminds me of my NDB beacons. Both are older tech that appear to be rapidly disappearing. Just last night I was happy to tune two new but weak Canadian LW beacons from my Michigan location on my D-808. Alas I then refreshed the dxcentre NDB list–at: https://www.dxinfocentre.com/ndb.htm–only to find that I would be losing 3 relatively strong beacons to decommission within weeks! Such is the life of an LW NDB chaser in the year 2023.

Thanks to Carlos for giving me something else to chase on SW HF!

John Johnson (N8ELK)

This is brilliant, John! The more you work with the app and reception, the better you’ll get at clear decodes. It’s a skill you’ll build very quickly. Thank you for sharing this!

QSL: Australian Radiofax Received in Brazil

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

For the first time, I received in Porto Alegre a noisy radiofax from the Bureau of Meteorology of Australia: Mean Sea Level Pressure (MSLP) map.

Frequency of 20469 kHz USB, 08h45 UTC.

Radiofax (noisy)

Original

My request for a QSL card was kindly answered (attached along the radiofax and the original chart from BoM’s website). Notice that BoM’s transmitter is 1 KW only!

I realize that your Radiofax decode wa noisy, but I feel like that’s an impressive feat considering the distance involved, the fact that your radio was a portable, and their output power was only 1,000 watts. Proper Radiofax DX! Thanks for sharing! 

Carlos notes passing of New Zealand MetService Radiofax

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Artwork by Carlos Latuff

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

Hello Thomas,

I’m sad to know that the New Zealand meteorological agency MetService, has retired radiofax in July 1st, and is focusing on “modern solutions” of sending synoptic charts to vessels. In 2021 I received several radiofax charts from MetService in Porto Alegre.

https://about.metservice.com/our-company/national-weather-services/retirement-of-radiofax

This is a video I shot in 2020:

Carlos improves quality of radiofax decodes

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

I made some adjustments and now I receive better quality radiofaxes. Since I started receiving radiofaxes in 2021, I had forgotten a fundamental detail.

To tune 1.9kHz lower than the advertised frequency. For example, the frequency of Kyodo News is 16971 kHz. I therefore tune in 16970 kHz. Of course, the fact that I tune in at 4:10 am in Brazil also makes a difference, as the propagation is quite good at that time.

Thank you for sharing that tip with up about moving down 1.9 kHz lower than the broadcast frequency. It certainly works–your decodes a very clean.

Carlos pulls headlines from Kyodo News radiofax

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

Kyodo News is a Japanese news agency, the only one in the world that still transmits news via radiofax to Japanese vessels, on shortwave frequency of 16971 kHz USB. The international radiofax transmission standard is 120 lines per minute, but the Kyodo News standard is 60 lines per minute.

However, the retransmission of the bulletin in English is done at a cadence of 120 lpm. I’m using an Android application called HF Weather Fax with which I’m decoding the radio signal coming from Japan and received in Porto Alegre, Brazil. The receiver is the Xhdata D-808 and the antenna is a magnetic loop. The image arrived this morning in Porto Alegre, at 4:10 am local time, quite noisy and with a lot of effort I managed to decipher some headlines.