HFU HF Underground
Loggings => HF Mystery Signals => Topic started by: jasmine on February 01, 2020, 1735 UTC
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Sorry if this is the wrong forum for this question but does anyone know what this signal is? It sounds digital but its bandwidth is very wide and covers 200khz of space between 6750-6950khz. It doesnt look or sound like CODAR at all either.
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Haven't seen anything like that on East Coast SDR's today... been quite dead actually.
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Without a screen shot, a recording, or more information than provided the possibility of identifying this is not very high.
With that said, there are two Chinese radars setting right next to each other on center freqs of 6795 and 6930 kHz. ANd they have been there most of the morning, so it might be the signal you mean if you are on the west coast or using west coast / Pacific receivers. If I remember right you are in the north west so that becomes a strong contender. Between the two of them they are pretty much covering the range 6760 to 6950 kHz for me. These radars do not sound like CODAR or PLUTO, as they use a different modulation technique. These radars sound more "data" like. They sound more similar to this recording https://www.youtube.com/watch?v=0qCfUUF6EBI however the current radars are operating at a higher rep rate, so they tend to smear the pulses more to the ear, the pulses sound less well defined.
Another recording of various similar Chinese radars here: https://www.youtube.com/watch?v=xomCC9uSaYk
T!
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i recorded the spectrum in SDRUno. i'll try to find a place to upload it but yeah your description of how it sounds is exactly what i heard.
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I would start with just posting up a screen shot. If it is one of the radars we can probably tell from that. If not a radar we might need more.
In general, a screen shot and an audio recording will do. Along with date and time (UTC). When you do an audio rec for these purposes the mode of the receiver is important, both what it is set to and that people know the setting. For most signals USB mode and a filter setting wide enough to get the whole signal inside is a good starting point, if the signal is too wide for max filter width then just as wide as you can grab may be fine. Seldom is there need for one of the big I/Q files, audio files are much smaller.
T!
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That range sounds normal at 0020utc here in Chicagoland.
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This morning I see the same two Chinese radars in that frequency range. This is what it looks like here:
(https://a4.pbase.com/o12/50/78250/1/170374049.1eVgbbzW.2x_CHN_rad__1434z.jpg)
T!
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sorry it took so long for me to reply, i hadn't realized the message was moved here but here is a waterfall, it looks like the mystery was solved, HF Trading (https://www.hfunderground.com/board/index.php/topic,44885.0.html) and Chinese Over-the-Horizon Radars as mentioned above.(https://i.imgur.com/xdHmnwl.png)