RFI? Or something else?

Get help identifying an unknown signal.
Post Reply
EODSarge
Posts: 6
Joined: Wed Jan 23, 2019 12:57 am

RFI? Or something else?

Post by EODSarge » Sat Jan 26, 2019 1:36 am

I see these three waterfall patterns a lot, usually on HF in direct sampling with an RTL-SDR Blog V3 and SDR#. Never had any experience with frequency waterfalls before.

This one sounds digital to me (on the right; on the left is a time signal):

Image

Two in one: On the left is a sweep across that band of frequencies; on the right is what looks like a braided rope, both unknown to me:

Image

I do live within less than a mile of a regional commuter airport and ~40 miles from Hartsfield International; though ADS-B and airband are great!

rtlsdrblog
Site Admin
Posts: 2434
Joined: Mon Nov 19, 2012 11:54 pm

Re: RFI? Or something else?

Post by rtlsdrblog » Sat Jan 26, 2019 2:50 am

Those are most likely over the horizon radar pulses e.g. https://www.sigidwiki.com/wiki/Jindalee ... ork_(JORN)

EODSarge
Posts: 6
Joined: Wed Jan 23, 2019 12:57 am

Re: RFI? Or something else?

Post by EODSarge » Sat Jan 26, 2019 9:30 pm

The top right one?

snn47
Posts: 192
Joined: Tue Dec 27, 2016 11:00 pm

Re: RFI? Or something else?

Post by snn47 » Wed Jan 30, 2019 6:13 am

A OTH can also look like the chineese OTH around 7 MHz http://www.arrl.org/news/chinese-over-t ... -40-meters Image
As the newsletter reported: “A jumping Chinese OTH radar covered the CW DX-edge of our exclusive 7 MHz band on November 17 at about 1500 UTC and later (long lasting).” The signal was 67 sweeps per second with a 10 kHz bandwidth

Post Reply