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spurious emissions from kiwisdr on 144,010
Hi,
i notice strong emissions on multiple frequencies from the kiwisdr or the attached beglebone green. The emissions are realy strong.
The most anoying frequency is in the 2m ham Band on 144,010. Has anyone else noticed this?
Best regards
Robert, db1jj
i notice strong emissions on multiple frequencies from the kiwisdr or the attached beglebone green. The emissions are realy strong.
The most anoying frequency is in the 2m ham Band on 144,010. Has anyone else noticed this?
Best regards
Robert, db1jj
Comments
1. I added a clip-on-ferrite and some ferrite cores to the 5 V power cord.
2. I added a common mode choke to the ethernet cable
3. I disconnected the gps
4. I disconnected the Antenna
I opened a client session with Firefox on the kiwisdr. On my Airspy with sdr-console (first screenshot)
Then i close Firefox. after about 30 to 60 sec the noisespectrum changes. (second screenshot)
Then i log in the thw kiwisdr via ssh and enter cdp and then mst (you see the effect of cdp and mst on the third screenshot
In a last try i started the kiwisdr, with only ethernet and power connected. opened one client via Firefox and then removed the ethernet cable. And even then with no possible ground loop ( becaus kiwisdrs only connection is power), i get the noise peak. (last screenshot, you see when i unplugged ethernet)
Attachments:
https://forum.kiwisdr.com/uploads/Uploader/60/6e5ce173f5d0ad8d1cdfc9a3f259b7.jpg
https://forum.kiwisdr.com/uploads/Uploader/a8/514cfdc276299db57a3954b0a5404f.jpg
https://forum.kiwisdr.com/uploads/Uploader/43/f02321d1a80711a5f4c2d13129c214.png
https://forum.kiwisdr.com/uploads/Uploader/49/68ff5db3fa45f0cfe8b51b5b49e4e7.png
https://forum.kiwisdr.com/uploads/Uploader/24/b8d98ebea75691ead55912ae2659f6.png
https://forum.kiwisdr.com/uploads/Uploader/b5/9ee47b61d9c053baf7ccd62d93ed6b.png
I try this again later. If this is the case, does the BB standalone test make sense?
I think the driver strenth and measurement with the near field probe is a good starting point.
I also have a beaglebone black (the one with hdmi ) lying around. Perhaps it has something to do with the layout of the bb-green.