Morning folks.. I find myself wrestling with PC emissions again. No names this time :-)
Above 500 MHz, I'm seeing a bunch of reasonably stable harmonics with about a 33 MHz spacing. Any thoughts as to what they may be from? I've played with all the case openings etc, and also added a ferrite bead to every cable leaving the MB... only minimal effect on this particular set of emissions. Ironically, the cooling fan is a big problem, it's powered from a 5 volt source that's very noisy. Consequently, the wires going to it radiate like crazy... I believe the MotherBoard is clocking around 1 GHz. Cheers, Derek N. Walton Owner L F Research EMC Design and Test Facility Poplar Grove, Illinois, USA www.lfresearch.com
