What is this huge signal?

KA7U

Listening to CW on the 40 meter band and this wideband signal showed up. Opened the band spread and found two other instances of similar signal, or is it generated noise from source?

Ron

KA7U

Attachments:
https://forum.kiwisdr.com/uploads/Uploader/ff/7078ede13a1ce9be9ef7b33c3844a8.png
https://forum.kiwisdr.com/uploads/Uploader/a5/d240bd967bb26b254dacf394351ed9.png
https://forum.kiwisdr.com/uploads/Uploader/89/819995f12c870f1be9f68e3a0c13a9.png

jks

Most likely an OTHR. But most of the common ones are not that wide and (generally) stay out of the ham bands. The definitive guide is here: http://www.iarums-r1.org/iarums/radar-2013.pdf  Maybe China? (see section 2.3)

If you zoom all the way in you can measure the repetition rate by looking at the spacing of the carriers. That will help with an ID. OTHR out of Cyprus by the US/UK is usually 20 kHz wide and the Russians 14 kHz.

KA7U

These carriers are closer spaced. OTHR is probably it, and the signals are going strong on the bandscope in the 3 locations.

Ron

KA7U

Attachments:
https://forum.kiwisdr.com/uploads/Uploader/e3/7988a31417458e37194f453334df56.png

WA2ZKD

I would rule out any ECCM stuff as there is no randomness

KA7U

More similar signals but short duration and seem to have multiple stations transmitting on different frequencies...

Ron 

KA7U

Attachments:
https://forum.kiwisdr.com/uploads/Uploader/67/bd092a15e5abef9d2dc5c21d0275e2.png
https://forum.kiwisdr.com/uploads/Uploader/df/270d05f201d810e00816c44f65061e.png
https://forum.kiwisdr.com/uploads/Uploader/31/28f9854e79115e790b53c3e2004074.png

G8JNJ

Hi Ron,

It's probably Super Darn. I normally see it around 12MHz but your screen grabs look very similar.

https://en.wikipedia.org/wiki/Super_Dual_Auroral_Radar_Network

Regards,

Martin - G8JNJ

Token

The first set posted by KA7U, showing the radar on 7020 kHz, those are Chinese OTH-SW radars. I have seen as many as 12 frequencies active at one time for these specific radars. Keep in mind these are not LFM or FMOP waveforms, as the British PLUTO (from Cyprus) or the Russian 29B6 radar are, these use BPSK on the pulse. The Chinese OTH-B radars use waveforms more similar to what is seen with PLUTO and 29B6.

And yes, the second set of radars, marked "wierddigi", are indeed SuperDARN.

T!