gandogujju Posted January 18, 2018 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.
Lista Posted January 18, 2018 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
Recommended Posts