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Loggings => HF Mystery Signals => Topic started by: IZ5PQT on March 23, 2015, 1442 UTC

Title: Wideband signal on 16 m and 11 m
Post by: IZ5PQT on March 23, 2015, 1442 UTC

Hello

I came across two puzzling signals which look very similar.
Their spectrum extends for 20 kHz: 17540-17560 kHz (S9) and 25920-25940 kHz (S9+10).
The shape is flat but with several peaks equally spaced. In AM mode it sounds like
a harsh 50 Hz or 100 Hz loud signal, but with different pitch in the two cases.
 Listened to in Pisa (Italy) with an
ELAD-FDM-S2 and a longwire.
2015.03.23

• until 1430 both signals on
• at 1434 both disappear
• both for sure present also previous day

Screenshots
http://www.televideo.ws/Shared/23-03-2015 15-21-14.png (http://www.televideo.ws/Shared/23-03-2015 15-21-14.png)
http://www.televideo.ws/Shared/23-03-2015 15-19-26.png (http://www.televideo.ws/Shared/23-03-2015 15-19-26.png)
73 Giovanni

Title: Re: Wideband signal on 16 m and 11 m
Post by: Token on March 23, 2015, 1836 UTC

Without a recording (preferably in USB mode, widest bandwidth possible) it is difficult to be sure.  However this is almost certainly the British PLUTO radar, from Cyprus.  The bandwidth is correct (20 kHz is its most common swept width, but not its only width) , the appearance is correct, and the most common mode for this radar is its 50 Hz sweep repetition rate.

Go here ( http://www.hfunderground.com/wiki/Signal_Identification#Non_Communications_Modes ) look for the PLUTO entry.  Play the sound files.  Keep in mind those are recorded in USB, and will sound different than what you heard in AM.

T!

Title: Re: Wideband signal on 16 m and 11 m
Post by: IZ5PQT on March 23, 2015, 2012 UTC

thanks! I suspected that it could be some OTHR. The information on PLUTO on the page suggests that I have really listened to it.

Giovanni