HFU HF Underground
Loggings => HF Mystery Signals => Topic started by: IQ_imbalance on January 11, 2019, 2017 UTC
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Maybe our 8000kHz carrier moved to a new frequency? -87dBm here, started around 1914 UTC 11 Jan. The spectrogram looks very similar. TDoA is all over the place, but seems to converge in the midatlantic area somewhere.
(https://i.imgur.com/GmxbDIU.png?1)
(https://i.imgur.com/sUqdxlK.png)
(https://i.imgur.com/Ez9JDV9.png)
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16;51Z 1/12/2019 -51dBm in NH on a 51' vertical wire. -67dBm on a 124'EFW at +100' AGL in an E/W configuration.
The 8000 kHz carrier not existent at this time at all.
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1739 UTC- 9000 kHz signal S5 in WNY.
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Has it moved again? Would be nice to catch some indication on the spectrum that there was a switch.....
Any TDoA experts care to weigh in? Are we just chasing timing errors or is this carrier really being broadcast at multiple sites?
(https://i.imgur.com/8RTkCnF.png)
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Strong carrier on 9000 kHz at 1930 UTC 12 Jan 2019 tune-in time, still going strong at 1948 UTC with S9+10db signal on the COMMSIGMA KiwiSDR on the CT/MA border. No modulation or anything else, just a steady carrier.
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The spectrogram picture posted looks to me like a featureless carrier, the "features" look like Doppler shift in reflected energy from aircraft.
I am no expert, but at a guess the TDOA results are all over the place because there is no modulation. If there are indeed no features on the carrier, just a dead carrier, the Kiwi TDOA techniques, as I understand them, cannot be applied. So yeah, you can TDOA away, but the answers will be wrong, or at best a lucky guess.
T!
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Thanks!! No point chasing TDoA if it's just analyzing noise.
One update....there's some drift in the carrier this afternoon. Looks like it's a few Hz below 9000kHz now, but drifting back up.....
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The spectrogram picture posted looks to me like a featureless carrier, the "features" look like Doppler shift in reflected energy from aircraft.
I am no expert, but at a guess the TDOA results are all over the place because there is no modulation. If there are indeed no features on the carrier, just a dead carrier, the Kiwi TDOA techniques, as I understand them, cannot be applied. So yeah, you can TDOA away, but the answers will be wrong, or at best a lucky guess.
T!
And this is why we need a net of people who can df the old fashioned way.