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: Unidentified mode on 6335 kHz  (Read 2919 times)

Offline n1kgh

  • Newbie
  • *
  • Posts: 8
    • View Profile
    • Email
Unidentified mode on 6335 kHz
« on: April 05, 2013, 1236 UTC »
What is this mode on 6335 kHz?  It resembles ALE and DRM and I have seen it often, but haven't found a match with any online samples.

Offline Token

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 2121
    • View Profile
Re: Unidentified mode on 6335 kHz
« Reply #1 on: April 05, 2013, 1353 UTC »
In order of importance to assist in IDing a signal: recording (audio or I/Q), screen shot of spectrogram (such as using SpectraVue, Spectrum Lab, or Spectrogram 16, but anything that will show a waterfall will help), date, time, frequency, and mode of operation.  Aproximate location you heard it from, and by this I mean the location of the receiver, just in case you are using a remote.

From your description it is impossible to say what you might have heard.  For example, right now locally (west coast) I hear the edge of a North Korean jammer on 6335 kHz USB, but if I go to an east cost remote I have off tuned STANAG 4285 and no sign of the jammer, and when I go to an MA remote I see nothing on that freq at all.

Not trying to be snarky or anything, just saying that the more data you provide the more likely you are to get a meaningful answer.

T!
« Last Edit: April 05, 2013, 1605 UTC by Token »
T!
Mojave Desert, California USA

Offline n1kgh

  • Newbie
  • *
  • Posts: 8
    • View Profile
    • Email
Re: Unidentified mode on 6335 kHz
« Reply #2 on: April 05, 2013, 1723 UTC »
Location is Salem, MA and this was heard around 0200Z UTC Friday 4/5, and until I get another spectrogram, the attached image is the best I can do.  I don't care so much who sent it--yet--as I do what mode it matches.  I have other screencaps.

Offline n1kgh

  • Newbie
  • *
  • Posts: 8
    • View Profile
    • Email
Re: Unidentified mode on 6335 kHz
« Reply #3 on: April 05, 2013, 1736 UTC »
For comparison, this is another signal at 4281.9 (center frequency probably 4282), heard on 3/17 at 2325 UTC, same location (Salem, MA).  I don't know if this is the same entity as the 6 MHz logging.

Offline Token

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 2121
    • View Profile
Re: Unidentified mode on 6335 kHz
« Reply #4 on: April 05, 2013, 1738 UTC »
Location is Salem, MA and this was heard around 0200Z UTC Friday 4/5, and until I get another spectrogram, the attached image is the best I can do.  I don't care so much who sent it--yet--as I do what mode it matches.  I have other screencaps.


No image seen here, nothing embedded or linked that I can see.

At this point, wihtout more to go on, it is totally a guess, but you are probably describing a STANAG mode, most commonly 4285.  I say this for a couple of reasons, it looks something like DRM but more narrow, and I know 4280 kHz USB is an S4285 channel.

If it is S4285 the chances of you finding out who is sending is pretty slim, almost all 4285 is encrypted.  I will try to upload an example to YouTube a bit later today, time permitting.

(edit)  I uploaded an example of S4285 to YouTube.  Compare and see if this is what you are looking at.  Pay attention to the width of the signal, there are several other techniques that look very similar.
http://www.youtube.com/watch?v=u-CgZNJIAVs


T!
« Last Edit: April 06, 2013, 0008 UTC by Token »
T!
Mojave Desert, California USA