Amund,
You do not HAVE to be in a chamber to keep working on this. Since there is only one Vcc pin (which processor IS this? - be SURE there is only one Vcc pin; you may have an unfiltered, unconnected Vcc pin or two) you are limited in how many capacitors you can attach to it. This doesn't matter; if you filtered power, and got 7 dB, you've done there what CAN be done there and should look look at other things. Troubleshoot the board. I too have thrown solutions at problems without knowing what exactly was wrong. It takes too long and costs too much. Find the source. A small 'scope probe, with the end taped over, makes a serviceable E-field probe. And you can make a small (~5 mm) shielded loop out of subminiature coax by turning it back on itself. This will allow you to sweep the board for traces that have the most current at frequencies of concern. Once you know where they are, you will be able to deal with how it is coupling. I once used such a small loop to show where clock traces went -- through a nickel-paint shielded chassis. It surprised the folks I showed it to, and got the attention of the coating people as well. We'd been throwing solutions at the product for some time without effect. If a fix doesn't work, you did not put it where it COULD work. I've done this too many times to be proud of the "horror stories," but I am alert to it now! Find the problem. Good luck! Cortland ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
