We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: UNID 6942.6 USB 0041 UTC 11 Dec 2013  (Read 1489 times)

Offline OldSeaRock

  • Full Member
  • ***
  • Posts: 121
  • Earth, TX
    • View Profile
UNID 6942.6 USB 0041 UTC 11 Dec 2013
« on: December 11, 2013, 0041 UTC »
Hell of a noise - don't know what it is.   S-9 at peaks in Tejas.

dit-dit-dit-dit-dit-dit (NOISE after 6 dits)

00:44 UTC  and now it sounds like there are two of them.

00:48 - now it's eight dits before a noise.
« Last Edit: December 11, 2013, 0049 UTC by OldSeaRock »
eQsl appreciated:  theoldsearock@yahoo.com
Listening on & off since 1968.  Howdy from Tejas!

rdla4

  • Guest
Re: UNID 6942.6 USB 0041 UTC 11 Dec 2013
« Reply #1 on: December 11, 2013, 0145 UTC »
Link 11 Tactical data link. This thing will show up and spend <sometimes> days on the same frequency. It usually likes to park at 6945-6950.

Offline Token

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 2122
    • View Profile
Re: UNID 6942.6 USB 0041 UTC 11 Dec 2013
« Reply #2 on: December 11, 2013, 0253 UTC »
Actual tuned frequency is 6942.0 kHz, tonight it is USB only, but it can also be LSB or even ISB, different data on LSB and USB.  When properly tuned the Doppler Tone (lowest tone) is at 605 Hz and the Synchronization Tone (highest tone) is at 2915 Hz.  You will note the rhythm changing as different units enter the net and as different data is sent, suffice to say it does not always sound the same.

This pops up in the band often, and might be found on any frequency at all.  Typically it is below 14 MHz when on HF and is also found in UHF.  An older thread with a description of what Link 11 is can be found here:
http://www.hfunderground.com/board/index.php/topic,12731.0.html

T!
T!
Mojave Desert, California USA

Offline OldSeaRock

  • Full Member
  • ***
  • Posts: 121
  • Earth, TX
    • View Profile
Re: UNID 6942.6 USB 0041 UTC 11 Dec 2013
« Reply #3 on: December 11, 2013, 1740 UTC »
Thanks for the ID.  Link 11.  I'll check out the info.
eQsl appreciated:  theoldsearock@yahoo.com
Listening on & off since 1968.  Howdy from Tejas!