gandogujju Posted January 18, 2018 Share Posted January 18, 2018 Hello, I am using the Olimex OLinuxino and I find a constant noise at about 866.725MHz or thereabout in every board. While low, at -100dBm, when using it with IoT radios this is the band in India and it is quite a pain in applications requiring high sensitivity. This particular board had it pretty nasty at -86dB. I have tried with changing the DDR frequency as well as the CPU clock, however this nuisance refuses to go away. What can be done to get rid of this noise ? I have tried multiple boards -- Olinuxino (multiple), Marsboard, but each has some noise in exactly same band near 866MHz. Please advise. Link to comment Share on other sites More sharing options...
Lista Posted January 18, 2018 Share Posted January 18, 2018 I chased down EMI problems with A20-Micro in the past. We were using inside and enclosure with some sensitive ADCs. Had no access to a DSA, but main causes in my case were(in order of importance): -Power supply- We had a switching wall-wart type supply @12v. Replaced with battery, then with a better quality power supply. Ferrites on the supply cable helped a lot too. -Buck converter on board the A20-Micro is noisy- Try powering board by the 5v_Ext pins (obviously don't exceed 5v) If you get an improvement, please share another shot from your DSA. 2 Link to comment Share on other sites More sharing options...
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