HFU HF Underground

Loggings => HF Mystery Signals => Topic started by: ulx2 on May 02, 2018, 2114 UTC

Title: UNID Mode 6443.3 kHz 2045 UTC 2 May 2018
Post by: ulx2 on May 02, 2018, 2114 UTC

Unidentified mode. The signal has been received on 6443.3 kHz (approx.) in LSB. Time: 20.45 UTC, date: 2 May 2018.

Waterfall screenshot and mp3 recording from Twente web-SDR are attached.
The signal is currently audible also here, in Kyiv.

What it could be?

Title: Re: UNID Mode 6443.3 kHz 2045 UTC 2 May 2018
Post by: Josh on May 03, 2018, 1758 UTC

Batputer says it's fsk, 230Hz shift, 300Bd, 530Hz bandwidth. There's a CIS-12 log here recently but this sig's not CIS-12.

Title: Re: UNID Mode 6443.3 kHz 2045 UTC 2 May 2018
Post by: ulx2 on May 21, 2018, 0025 UTC

Thanks for the information, Josh.

Title: Re: UNID Mode 6443.3 kHz 2045 UTC 2 May 2018
Post by: Josh on May 21, 2018, 1654 UTC

Looked at it again and it's FM-Hell possibly, knew I'd heard something similar before. 122.5baud, 230Hz shift. Hell modes mess with automated mode classifiers (used when first looking at the signal) so it doubled the baud, but I knew I'd heard the pilot tone and burst before. No idea what the message is but here's a screencap of the output;
http://s000.tinyupload.com/index.php?file_id=00910469952425641313
The light and dark backgrounds are from me trying different offsets.


http://www.w1hkj.com/modes/feld.htm