10715 khz YL Numbers in Spanish

[SigIntel8600]

at 22:40 UTC, 10.715 MHZ, AM, YL with numbers and digital bursts in Spanish.

 

[ka3jjz]

Enigma station HM01- the Cubans are at it again (heh)...Mike

 

[GB46]

I'm hearing that number station right now at 22:14 UTC on 10715. Has anyone managed to decode those data bursts after every 5-digit group, or at least identified the digital mode used? The sound reminds me of the 57k baud modem I had back in the 90s for making dialup internet connections.

Some spy agency! :roll: They continue to use the same frequencies that have been widely known for years and are so predictable that they are listed in EiBi's shortwave schedules. :lol:

Their signal strength on my R75 is S9+10db, with very minor fading and clear audio. It's just as strong on my portable, too. This is with a 23 ft. reel antenna indoors on both receivers. Funny, but RHC never comes through that loud and clear, even though they're probably using the same transmitters..

 

[ka3jjz]

It's very likely RDFT, which is a mode associated exclusively to HM01. There is an app that supposedly decodes it, but from what I have heard, it's a bit dodgy and it's stability is not all that good. Even if you decode it, it's all letters and numbers, much like what the Russians (and others) do. A quick search of the UDXF logs confirms the guess.

Mike

 

[GB46]

It's very likely RDFT, which is a mode associated exclusively to HM01. There is an app that supposedly decodes it, but from what I have heard, it's a bit dodgy and it's stability is not all that good. Even if you decode it, it's all letters and numbers, much like what the Russians (and others) do. A quick search of the UDXF logs confirms the guess.

So perhaps the data sequences are simply echoing the voice transmissions. I once tried copying out those number groups to see if any of them were repeated, but that was before the data streams were added, and there were more of the groups. I did manage to see entire sequences repeated.

To the uninitiated, sequences of letters and numbers are meaningless anyway, as are the codes read out on the US GHFS frequencies, but they do add a sense of mystery that makes SWLing more interesting. Come to think of it, I don't understand most of the languages used by the shortwave broadcasters, either, but it's still fun to hear them.

 

[Token]

It's very likely RDFT, which is a mode associated exclusively to HM01. There is an app that supposedly decodes it, but from what I have heard, it's a bit dodgy and it's stability is not all that good. Even if you decode it, it's all letters and numbers, much like what the Russians (and others) do. A quick search of the UDXF logs confirms the guess.

The software is called DIGTRX. I believe it was written for Windows XP. Under XP it is fairly stable, however there are issues running it under newer OS's.

RDFT was a ham mode before SK01, and later HM01, adopted it.

The HM01 files are encoded before being sent. DIGTRX will demodulate the transmittedfiles, but not decrypt them. So you end up with a txt file, but it is still encrypted. That is, assuming the Cubans did their tasking correctly. It is reported that on at least one instance SK01 (the predecessor to todays HM01) sent a message without encrypting first, so that the DIGTRX demodulated txt file contained real words.

T!

 

[majoco]

Here yer go....

https://www.youtube.com/watch?v=Wvr6o7fBcTY

https://www.youtube.com/watch?v=Qrt1pN4CFCA

 

[GB46]

Here yer go....

https://www.youtube.com/watch?v=Wvr6o7fBcTY

https://www.youtube.com/watch?v=Qrt1pN4CFCA

Interesting! Thanks for the link. The only number stations I've heard over the last few years were the Cuban ones in Spanish. The first time I heard ham JT65 transmissions I didn't know what they were. At first I thought they were some kind of spy activity, until I finally installed the software to decode them. When I then ran across FT8 as well, I knew what to expect.

 

[ka3jjz]

We have another forum for discussing ham digital modes, but there are a number of such modes hams use, and more being experimented upon. We have a wiki page that introduces many of these modes here...

HF Digital Amateur Radio - The RadioReference Wiki

And while HM01 (the Enigma designator for the Cuban Intelligence service station) is very common, there are a great many more, some of them using modified ham digital modes (The Russian station XPA2 uses a variant of MFSK-16, as an example). Some have even been caught actually using ham modes - a few years ago stations starting popping up using PSK31 all the way up to PSK-125. Some have guessed that someone hacked the popular MultiPSK software to do this.

There is a what you might call a sub group within the UDXF that watches this activity very closely, and decodes these modes (altho they can't yet decrypt them). Here are but 2 of these resources;

ENIGMA2000

Numbers stations

Mike

 

[GB46]

We have another forum for discussing ham digital modes, but there are a number of such modes hams use, and more being experimented upon. We have a wiki page that introduces many of these modes here...

HF Digital Amateur Radio - The RadioReference Wiki

Yes, that wiki, and some posts, are what helped me identify JT65 and FT8. I have MultiPSK and have decoded ham RTTY and CW as well, but I hear the other amateur modes so seldom that I'm never ready to decode them. By the time MultiPSK comes up on my screen, the stations have gone off the air, or at least faded into oblivion. On the other hand, I pick up maritime navtex and fax signals far more often, and they're easy to decode.

Those numbers stations sure have a lot of followers! I've downloaded one of Enigma2000's lists, but under the current conditions, and with the high noise level here, I'm unlikely to hear any of the numbers stations except the Cuban ones.