HFU HF Underground
Loggings => HF Mystery Signals => Topic started by: MDK2 on September 25, 2016, 1656 UTC
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South Korean SWLer Moomin posted this to his youtube channel a few days ago wondering what it was. The closest I could come up with, is that this frequency was listed in N&O newsletter # 200 as a frequency used by M32a, a Russian Navy station. The designation M32a would indicate a morse code station, but this obviously is not CW.
Anyway, your sleuthing is welcome and if you think you know what it is, please comment on the video itself as well as here. Moomin is interested in an English translation of what the Russian OM is saying, if anyone reading this can speak the language.
https://www.youtube.com/watch?v=FiN8S_-qvko
7936 kHz
22 September 2016
1313z
QTH: Gyeonggi-do, Siheung-si, South Korea. I believe he uses SDRPlay and his antenna is a 303WA-2 MF/HF.
EDIT: It does sound a lot like 29B6 'Kontayner' OTH Radar per sididwiki. I'm not expert enough to call it, however.
EDIT 2: per quick discussion with Token on the pirate chat, it's a Russian OFDM modem.
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Hello.
The language on the clip is NOT Russian. Sounds rather Scandinavian for me (very tentatively). It's too hard to recognize exactly by 2-4 words. May be Swedish or Norwegian members could confirm or refute.
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EDIT 2: per quick discussion with Token on the pirate chat, it's a Russian OFDM modem.
What I said in chat was that IF it was Russian it was probably some kind of OFDM, however I had not yet had time to look at the signal in software, and I was bothered by the apparent Doppler tone on the wrong side of the data. The Russian systems typically put the Doppler tone above the data, say around 3300 Hz, this one apparently has a Doppler tone (judging by ear) below the data.
I still have not had a chance to look at the signal in detail, however I did get a chance to grab a histogram. I am pretty sure this signal is not a Russian modem, but rather it is MIL-STD 188-110 A/B Appen B, possibly in 39 x 44.44 Bd QPSK or some signal based on that system. Several people (including the Chinese) have come out with modifications to that format that can be hard to discern from the original.
(edit) I have looked closer at this signal, and yes, it is either MIL-STD 188-110A Appendix B, 39 tone, or one of the many slightly modified versions of that signal in use by multiple sources. The Bulgarians are known to use a version very similar to this, however I have not heard Bulgarians on that particular frequency.
T!
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Comments are most welcome on the youtube link itself, for those inclined to share their insights directly with "Moomin."