Unknown 4007 KHz USB DIGITAL ??

[Saint]

Can some one listen to the MP4 File of a digital sound I have been trying to decode and I have not been able too looks like rtty but the digital tracks are farther apart ?? encrypted signal ??
Steve

UNKNOWN DIGITAL.mp4

drive.google.com

 

[ka3jjz]

From our file here

Undecodeable NATO Digital Signals - The RadioReference Wiki

wiki.radioreference.com

it's likely a STANAG 4481 signal out of Maryland (4005 would be the center freq, sometimes written like this: 4005cf). On occasion - you really need to be johnny on the spot to find this - but stations like this will sometimes run a test tape in the clear instead of the encrypted junk. But you need to be VERY lucky to see it

Mike

 

[Saint]

From our file here

Undecodeable NATO Digital Signals - The RadioReference Wiki

wiki.radioreference.com

it's likely a STANAG 4481 signal out of Maryland (4005 would be the center freq, sometimes written like this: 4005cf). On occasion - you really need to be johnny on the spot to find this - but stations like this will sometimes run a test tape in the clear instead of the encrypted junk. But you need to be VERY lucky to see it

Mike

Hi Mike thanks for the information I always see this signal very strong all the time, I looked at Multipsk and can't see a decoder that would decode this, is there a decoder in Multipsk paid version to decode this . Steve

 

[Saint]

Just read the link you sent along and I see there is nothing that will decode this
Steve

 

[dlwtrunked]

It is an encrypted 75 Bd/850 Hz shift U.S. Navy transmission from the USAF *Andrews)/USN facility at Davidsonville, MD. The actual frequency is 4005 MHz. As others have said, nothing is going to decode it as the encryption requires the right classified key to do that. Other frequencies, with the same or similar USN transmissions to watch from there are:
4985 night
6487 day and night
9830 day and night
12015 day
15959 day

 

[Saint]

It is an encrypted 75 Bd/850 Hz shift U.S. Navy transmission from the USAF *Andrews)/USN facility at Davidsonville, MD. The actual frequency is 4005 MHz. As others have said, nothing is going to decode it as the encryption requires the right classified key to do that. Other frequencies, with the same or similar USN transmissions to watch from there are:
4985 night
6487 day and night
9830 day and night
12015 day
15959 day

OK thanks for all the info, Sad such a good strong signal and it can't be decoded but there are lots of other signal out there.
Steve

 

[ka3jjz]

There are quite a few STANAG logs every month in the UDXF. Most folks I think are using the hard core programs like Hoka or Krypto to analyze then, but unless you catch them running a test tape you will never decode it. STANAG 4285 is real popular, but as you noted STANAG 4481 is out there too....Mike

 

[dlwtrunked]

OK thanks for all the info, Sad such a good strong signal and it can't be decoded but there are lots of other signal out there.
Steve

It looks so strong as it is a simple signal being shifted between two frequencies with more modern stuff filling a bandwidth to be a much larger data rate. There is not much clear (unencrypted) stuff on HF now a days. When I was young (50 years ago), there was lots of radioteletype press, telegrams, military, weather, and others stuff as well as lots of FAX press photos and weather. Add in a lot of ship-to-shore cw. Todays HF is an *extreme* disappointment to what on had to receive around 1970 or so.

 

[ka3jjz]

While there isn't the level of clear HF digital as it was 50 years ago, there's still plenty to see. Weather broadcasts on NAVTEX and FAX are still pretty easy to find, there are literally hundreds (if not more) ALE networks (for the most part, they're in the clear), HFDL is out there (and that wasn't around back then...), GMDSS / DSC is also out there ....name your pleasure...Mike

 

[dlwtrunked]

While there isn't the level of clear HF digital as it was 50 years ago, there's still plenty to see. Weather broadcasts on NAVTEX and FAX are still pretty easy to find, there are literally hundreds (if not more) ALE networks (for the most part, they're in the clear), HFDL is out there (and that wasn't around back then...), GMDSS / DSC is also out there ....name your pleasure...Mike

There is far lest FAX than back then I do agree ALE is interesting and HFDL also. But still fall less interesting stuf than 50 years ago when one would encounter 16 channel military FDM RTTY which would include generally one weather channel and one press channel. I still have press FAX from back then as well as telegraph links between countries (Moscow-Cuba was a favoirte as was Miami-Cuba). The digital military traffic is also much less now. And even copying back then cw/FTTY Firestone's Liberia plantation working their Akron station. And I still have an RTTY message sent on a VOA RTTY house keeping channel that was sent to me via that channel after they found the transmitter spur of that channel that I phone them about. Back then Russian trawlers were active on mostly 8 MHz with traffic too and from Russian and there was other SITOR ship-shore traffic. Even the FCC DF network ran an HF repeater system to cooriunate (yes, encrypted but toy encryption than some us had no problem copying 100% of their traffic). It is not so much the amount of traffic today but the variety in the clear that is missed. Today is often boring in comparison as copying locations only in some cases does not compare to actually copying messages back then.