I read in !emc-pstc that Gordon,Ian <[email protected]> wrote (in <E1BA0362B28ED211A1E80008C71EA3060206FD2E@EXC_EAS01>) about 'Temperature effects on conducted emissions?' on Mon, 11 Aug 2003:
>Can anyone suggest a means by which the indicated signal from a LISN + >transient limiter + receiver combination can result in a 30dB change >over one month? I used the same "reference source" and test >configuration on both occasions to generate emissions. However, the >source is merely a piece of standard equipment and not intended as a >calibration reference. The temperature has varied considerably over the >last month but I would not have thought this could result in a 30dB >variation. Most unlikely. Bad cable? Cables can go bad in ways you wouldn't believe. I've had one that measured 30 ohms end-end of the inner conductor and another that had its own 50 ohm termination built in! >Alternatively, can anyone suggest a means of constructing a >reference source >which may be connected to the LISN input? I haven't thought deeply about it, but the LISN looks like 50 ohms or more to the EUT. And you don't need much voltage across that 50 ohms to simulate a typical EUT. So a simple wideband noise-generator (ideally a thermionic noise diode) would be OK, I think. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! 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] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
