How to decode 8,692.500 Khz

[W1HD]

I'm new to all of this. The strongest digital signal I've come across is at 8692.500 (carrier frequency) which looks like twin mountain peaks on the spectrum view. I have FLdigi and MultiPSK and I still can't seem to decode this thing. Help!
I feel especially stupid as I've been a ham since the 1970s and it shouldn't be that hard...
Thanks in advance.
Bill - W1HD

 

[CrazyCalifornian]

Encrypted Military RTTY...

 

[W1HD]

Encrypted Military RTTY...

So no way to decode it? OK. On to bigger and better things! THANK YOU!

 

[dlwtrunked]

So no way to decode it? OK. On to bigger and better things! THANK YOU!

It is extremely unlikely that it is what he said. There are no reports of other than experimenters in that range. Can you give us a recording?

 

[ka3jjz]

Bill this is likely 8694 Dixon California STANAG 4481. Except in rare instances, these signals- used by NATO and other military- are encrypted. There are LOTS of these on the air - See this list from our wiki

Undecodeable NATO Digital Signals - The RadioReference Wiki

wiki.radioreference.com

The Russians have their own system(s) - some running MFSK4, 6 and 66 among many others. Their Navy often runs T600 (also known as CIS-36-50) and we have a zip file with over 400 freqs here...

Russian T600 Frequencies and Callsigns - The RadioReference Wiki

wiki.radioreference.com

If you are hunting for readable stuff just to get your feet wet, this article (again from our wiki) will be quite helpful

Testing Your New Setup - The RadioReference Wiki

wiki.radioreference.com

You would do well to join the UDXF reflector on the groups.io server. You will get an eyeful about things readable and not. The address is

UDXF groups.io Group

The Utility DXers Forum - UDXF is centered around the exchange of news and information relating to "utility" radio stations and signals, below 30 MHz. The Utility DXers Forum - UDXF is centered around the exchange of news and information relating to "utility" radio stations and signals, below...

groups.io

This ain't Yahoo. Very little if any spam or OT stuff here. Check out their home page which is listed there. You will be quite amazed at what you will find. Puts any other utility HF page - including our own - to shame

Mike

 

[ka3jjz]

It is extremely unlikely that it is what he said. There are no reports of other than experimenters in that range. Can you give us a recording?

No experimenters in the 8 Mhz range, for sure.

Mike

 

[dlwtrunked]

No experimenters in the 8 Mhz range, for sure.

Mike

You are right-sorry about that. I had just finished reading a 8000 Hz European experimental thread and did not read the subject line and with the text just saying 8692.5 without units, mistakenly my mind made them Hz like the last thread I had read. My appologies--particularly to the CrazyCalifornian. Anyway, the station on 8692 kHz is a NATO encrypted station (may be U.S. or other NATO member). The USN in Dixon California uses 8694 kHz (center frequency). Depending on how he measured the frequency, it may have been them.

 

[ka3jjz]

NP- as I mentioned there's a bunch of STANAGs out there, more so since the beginning of the Ukrainian war. The US is a NATO member, by the way. And there are several different protocols within STANAG, but the most common are 4285 and 4481 (which this might have been). Occasionally 5066 is noted but this is assumed to be used for file transfers, email and the like.

Mike

 

[popnokick]

Most likely STANAG 4481 because to the unaided ear the FSK audio of 4481 sounds much like conventional RTTY. Leading one to hear it and think, "Why can't I demodulate this? Sounds like any other RTTY signal." The other STANAG modes sound more like high speed PSK (which they are) and are not easily mistaken for the usual mark / space conventional RTTY. Audio and spectrum samples of these modes can be heard here (NOTE: Takes VERY long time to load due to size of samples) -
https://www.sigidwiki.com/wiki/Database

 

[dlwtrunked]

Most likely STANAG 4481 because to the unaided ear the FSK audio of 4481 sounds much like conventional RTTY. Leading one to hear it and think, "Why can't I demodulate this? Sounds like any other RTTY signal." The other STANAG modes sound more like high speed PSK (which they are) and are not easily mistaken for the usual mark / space conventional RTTY. Audio and spectrum samples of these modes can be heard here (NOTE: Takes VERY long time to load due to size of samples) -
https://www.sigidwiki.com/wiki/Database

The Dixon, CA station on 8694 kHz has been reported as 50 Bd FSK/850 Hz shift RTTY on the frequency. As the mode existed before the STANAG terminology and was used by NATO since before I started listening in the 1960's, those of us from back then just refer to it as 850 Hz shift encrypted FSK RTTY (though we know it is a STANAG mode, that is not as descriptive). (I once was a participant in a NATO STANAG meeting and was lucky as they wanted me to chair the group but my supervisor said "No" as they would not pay for my time.)

 

[ka3jjz]

If you want to get down in the weeds on analysis of digital signals, Antonio's site is one of the best. This is not for the faint of heart, though - it gets very technical very quickly. But he covers a plethoria of digital modes, both known and unknown

diario SWL I-56578 Antonio

HF utility & milcomm signals<br> <i>tony.anselmi@gmail.com</i>

i56578-swl.blogspot.com

Mike

 

[W1HD]

What can I say besides "Thank you"? I have so much to learn - my first "lesson" has been just how vast this whole HF decode universe is. So many modes, so much encryption. It's a bit overwhelming.

I will try to post audio in the future (once I learn how to record it - smile).

A couple of the replies I received referenced specific sites where helpful info may be found. I will investigate each with great appreciation.

Happy hunting and, again, thank you!

 

[ka3jjz]

Why don't I further blow a fellow ham's mind? This article has a great many specific links to digital (and audio routing) resources. I haven't cleaned this up in a bit, but most of this should still be good.

HF Appendix - The RadioReference Wiki

wiki.radioreference.com

Grab a large glass of your favorite tuning oil and enjoy.....Mike

 

[W1HD]

Why don't I further blow a fellow ham's mind? This article has a great many specific links to digital (and audio routing) resources. I haven't cleaned this up in a bit, but most of this should still be good.

HF Appendix - The RadioReference Wiki

wiki.radioreference.com

Grab a large glass of your favorite tuning oil and enjoy.....Mike

I did bookmark this one and spent an hour or so last night browsing. Thanks!