G8JNJ

@ Lonecrow

Looking back over some past notes, I think it's likely to be noise from Ethernet data. I was reminded about this when I tried my KiWi around 18MHz and found some weak signals similar to what you are observing, as I'd previously manged to reduce these to a fairly low level.

http://forum.kiwisdr.com/discussion/778/noise-at-roughly-60-khz-intervals

If you look at some of the screenshots that I'd attached to my post, they look a lot like what you are seeing and hearing.

The exact frequencies at which some of these signals are strongest will depend upon your Ethernet cable lengths and any switch / hub you are using.

Make up some simple 'sniffer' probes to use with your KiWi in order to locate local noise sources.






Copied from Keith Armstrong's excellent EMC notes.

http://www.compliance-club.com/archive/keitharmstrong/emc_testing1.html

http://www.compliance-club.com/archive/keitharmstrong/emc_testing2.html

Regards,

Martin - G8JNJ

@Hugobmf

I have just tried editing and saving a configuration on the admin pages and it worked OK for me running v1.216

When you enter a new value in to a text box, and then press 'enter', do you see the text box turn green for a short period ?

Regards,

Martin - G8JNJ

Should have said, these are the bursts centered on 4785KHz

See

http://www.hfindustry.com/meetings_presentations/presentation_materials/2017_sep_hfia/presentations/THALES_HFXL_HFIAsept2017_Presentation_final2_Bernier.pdf

Regards,

Martin - G8JNJ

Hi Dave,

I've just managed to perform four runs using different KiWi's (fortunately Emerald was available.

I used the widest I/Q filter bandwidth to straddle two sets of databursts that had no other transmissions at low level in the background.

The best (narrow red band) 'pairs' of plots from all four runs intersect St Eval and the composite best guess location is just off the West Cornish coast in the Irish sea.

Regards,

Martin - G8JNJ

Hi Dave,

See

http://forum.kiwisdr.com/discussion/comment/2631#Comment_2631

NVIS makes a real mess of TDoA on the LF bands.

You may have to try TDoA at a few different times if day, before you find stable propagation.

Regards,

Martin