Tag Archives: Digital Modes

The HF Voyager: Make contact with an “autonomous ocean-going drone”

The HF Voyager (Source: JRF Amateur Radio Club)

(Source: Southgate ARC)

David, AA6YQ, author of DXLab – ‘Better DXing Through (Free) Software’, posted the following: ‘Jupiter Research Foundation Amateur Radio Club (JRFARC) has integrated an HF transceiver with an autonomous ocean-going drone. Our mission is to deploy a ham radio station that roams the world’s oceans while providing an opportunity for amateur radio operators everywhere to make contacts with rare locations.’

“We sent this new Voyager out to the open ocean on its way to California on January 15th, 2018 as a passenger on the JRF HUMPACs mission. As they search for ‘missing’ humpback whales, JRF’s pilots will guide HF Voyager to sections of the Equatorial North Pacific that are not normally available to ham operators. The station will use FT8 and PSK-31 on the 20 meter band as its primary operating modes. You may also find it using WSPR in times of poor propagation.”

See http://www.jrfarc.org/hf-voyager/

The portal in http://hfvportal.jrfarc.org/ takes a minute or two to display data.

The club plans to give a certificate of recognition to operators world-wide that have a confirmed contact with the HF Voyager. In the future we hope to collaborate with Amateur Radio organizations and publishers to sponsor operating events and contests for HF Voyager contact milestones.

Gridsquare collectors, maritime operating fans, Islands on the Air participants, and all other hams interested in this unique opportunity to make a contact with an autonomous roving maritime station should find this to be an exciting new aspect of their favorite hobby.

Be sure to check out our HF Voyager Blog for updates and schedules:
http://www.jrfarc.org/hf-voyager-updates

I think this is a pretty fascinating project–especially if the system can withstand the rigors of ocean travel and can be tracked and picked up later for replacement and upgrades.

I had never spent much time on the HF digital modes until last year when I caught the FT8 bug. While FT8 lacks some of the social nuances of, say SSB voice and CW, it is a fascinating mode that seems to defy HF propagation rules. It’s certainly an accessible way to work HF stations across the globe with a very modest setup. I think it’s an ideal pairing for a project like the HF Voyager.

Even if you don’t have a ham radio license, with an HF receiver and a free PC application, you can receive/decode FT8 contacts from across the globe.

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DigiFAQ Updated: An HF Digital Decoding primer and reference tool

Many thanks to SWLing Post contributor, Mike Agner, who writes:

[S]ome 20 years ago, Mike Chace-Ortiz, Stan Skalsky, myself and a bunch of other folks put together a FAQ about digital modes on radio – specifically modes going from LW way up into the UHF spectrum- called the DigiFAQ 5.3. I was responsible for the HF Software section, and as you might know, back then it was all about the hardware. InfoTech was still around, and amateur digital modes using the PK232 were plentiful. There is a PDF-based copy on the UDXF website [click here to download].

Now jump ahead 20 years or so, and things have changed considerably. Hardware is no longer king, and soundcard-driven software has taken over the market. Even receivers have changed – the desktops of old (quite apart from the current batch of ham transceivers that have general coverage radios built in) have been pretty much supplanted by Software Defined Radios. Along with that, the digital modes themselves have changed drastically with some disappearing altogether, with new ones like ALE going to the head of the pack. Too, the original DigiFAQ combined many ham-related modes along with everything else.

[O]ur original work didn’t really address some of the basic questions newcomers to this side of the hobby might have, [s]o with Mike Chace-Ortiz’s help, I have been involved in rewriting and updating the FAQ. Its approach is different – we start from topics like discussing radios, SDRs, some of the terminology you will see on mailing lists like the UDXF and much more. Only after we cover all of this do we discuss decoders – and even here, this topic is broken down even further, to include those decoders that play nice with some SDRs, and some of the tools you can use to help analyze an unknown signal.

Then we go into the modes (most are HF related, but we do touch on one or two common LW modes). We identify those modes that are dead, and separate them from the rarely used/active ones. Where possible we also supply waterfalls for each.

We also have an extensive appendix with a whole bunch of links for additional reading.

Perhaps of greatest use to newcomers is a listing of known scheduled broadcasts, so they can test what they download without wandering all over the place, hoping to find a readable signal – and potentially getting turned off when the don’t find one. We have also recovered a few articles from the old WUN archives as well as from SPEEDX (Society to Preserve the Engrossing Enjoyment of DXing – folded a long time ago) on certain digital related topics, such as discussing how to read an AMVER transmission.

It should be noted that we also sent the amateur radio digital modes to their own page for a very simple reason – while these modes are well understood (and many have their own devoted page that cover their mode far better than we can), the single biggest reason was that these modes can NEVER be encrypted (at least in the US, and likely other countries as well). Sad to say, but there are many modes outside of the amateur bands that we will never be able to read, and some whose purpose is unclear. As of this writing, many UDXF members are noting signals thought to be Russian in origin, utilizing a variation of MFSK-16, a mode generally associated with amateur radio.

Is this document complete? Not even close. It’s designed to be something of an introduction, with enough detail to hopefully draw in both the newcomer and experienced. There are new modes being identified, new networks, and even new players being found all the time. There’s still more work to be done on this, and this is yet another change to the original DigiFAQ- it’s hosted on the RadioReference wiki, where any member (with a free ID) can edit and add to it.

The URL is: http://wiki.radioreference.com/index.php/HF_Digital_Decoding

Regards, Mike

Thank you for sharing this update, Mike!

I receive a lot of questions regarding digital modes even though it’s an area of the hobby where I’m quite weak. I’m pleased that you, Mike, Stan and your team are all working to keep a reference source up-to-date for folks exploring this dynamic part of the radio hobby.

Click here to visit DigiFAQ at RadioReference.com.

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WRMI to showcase digital modes via analog radio

31-meter-Spectrum (Source: VOA Radiogram via Richard Langley)

WRMI, Radio Miami International, will showcase digital text and images via analog radio in a half-hour special broadcast to be transmitted nine times (at least), beginning Saturday, 13 August.

The broadcast will mostly be in MFSK32 centered on 1500 Hz. There will also be segments in MFSK64, MFSK32 centered on 2200 Hz, and Olivia 64-2000. The program will include MFSK images, examples of non-Latin alphabets, and an Flmsg transmission. You will also hear “co-channel” music.

To decode the modes on the WRMI broadcast, Fldigi software is recommended. Download it fromhttps://sourceforge.net/projects/fldigi/files/fldigi/ . The main Fldigi website is http://www.w1hkj.com.

And you will use the companion program Flmsg. Download it fromhttps://sourceforge.net/projects/fldigi/files/flmsg/ .

To make Flmsg work with Fldigi, in Fldigi: Configure > Misc > NBEMS > under Reception of flmsg files, select Open with flmsg and Open in browser, and below that indicate where your Flmsg.exe file is located – probably somewhere in Program Files(x86).

For correct decoding of the languages with diacritics, or using non-Latin alphabets, in Fldigi: Configure > Colors & Fonts > RxTx > in the Rx/Tx Character set menu, select UTF-8.

For Fldigi to automatically select the mode and the center audio frequency of the mode, select RxID (upper right of the interface) by left clicking. In newer versions of Fldigi, also right click on RxID and select Passband.

You can decode this WRMI special broadcast as it is broadcast, or from your recording.

TRANSMISSION SCHEDULE

Via WRMI’s transmitters at Okeechobee, Florida, except where noted:

Saturday 13 August 0030-0100 UTC on 7730 kHz (285 degrees azimuth)
Saturday 13 August 0730-0800 UTC on 5850 kHz (315 degrees)
Saturday 13 August 1330-1400 UTC on 11580 kHz (44 degrees)
Saturday 13 August 2200-2230 UTC on 5950 kHz (181 degrees)
Sunday 14 August 0230-0300 UTC on 11580 kHz (44 degrees)
Sunday 14 August 2130-2200 UTC on 15770 kHz (44 degrees)*
Sunday 14 August 2330-2330 UTC on 11580 kHz (44 degrees)*
Monday 15 August 2000-2030 UTC on 6070 kHz* **
Tuesday 16 August 2130-2200 UTC on 15770 kHz (44 degrees)

* Preempts DigiDX, usually heard at this time

** Via Channel 292, Germany

Many of these broadcasts will be heard outside their nominal target areas.

Reception reports to Jeff: info (at) wrmi.net

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There’s a pattern in that noise!

Digital-Image-VOA-Radiogram

Many thanks to SWLing Post contributor, @K7al_L3afta, who just shared the image (above) and noted, on Twitter:

“I just discovered the noise at the start of [the VOA Radiogram has] a purpose!” 

That’s a brilliant discovery!

Click here to learn about the VOA Radiogram.

Click here to follow @K7al_L3afta on Twitter.

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Update: German communications regulator to allow AM digital modes

FLdigi-VOARadiogram

As a follow-up to a previous post, many thanks to several SWLing Post readers who noted this news on the VOA Radiogram website:

The German communications regulator Bundesnetzagentur has changed its mind about allowing digital modes on shortwave broadcast transmitters in Germany. Apparently BNetzA thought that Channel 292 was transmitting the text and images in single sideband (SSB), which is how amateurs, military, etc, transmit the digital modes. Now that they know that the MFSK32 and other modes are sent as program audio on an analogue amplitude-modulation shortwave transmitter, their objections were withdrawn.  (It’s similar to A2A modulated CW.)

BNetzA prefers that the term MFSK32 not be used to describe these broadcasts, but we have to specify the mode so that you can set Fldigi or other decoding software to the correct mode. In any case, the weekly MFSK32 transmission will resume on The Mighty KBC, and DigiDX will return to Channel 292.

Meanwhile, VOA Radiogram this weekend will be all MFSK32 except for the transmission schedule in Olivia 64-2000 under the closing music.                       

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