Dear Ken Sorry to be so late replying, but I have been unable to read any of the correspondence in this thread for a week.
In an attempt to spare the emc-pstc more of our arguing I will not reply in detail to three of your emails, one from the 6th Jan, and two from the 7th Jan, because they all deal with what I think is the core issue: "Can the emissions from an 'intentional radiator' such as a laptop that is compliant with CISPR22 and/or FCC limits interfere with an electronic product that is not an intentional radio receiver and possibly cause a safety problem?" Have I summarised the issue correctly? I am of the opinion, and I think the other correspondents are too, that the answer is: "Yes they can in some circumstances but it should be unlikely these days". I think the reasons for this conclusion include... a) Products with compliant fields at 10 metres distance might have considerably stronger fields closer to, especially in their near field. b) The mandatory standards don't measure all the frequencies that could be emitted from the compliant laptop and possibly cause interference (e.g. audio frequency magnetic fields from fluctuating dc power supply currents can interfere directly with nearby audio or low-frequency transducer circuits). c) Some circuits are very sensitive (especially some transducer amplifiers), or not well-designed for RF immunity, or both at the same time. What do you think, Ken? What do the other emc-pstc members think? Can we please finish this debate now? Regards, Keith Armstrong PS: I will not be able to reply to postings in this thread for about another week.
