Could the problem have something to do with the field "leveling" algorithm?
Perhaps there is a transient spike in the field as it sweeps from one frequency to another? I only say this because I have been to a lab that manually controls the field (well, they used to about 9 years ago anyway). While testing there, the technician would sometimes have a tough time leveling the field at certain frequencies, possibly due to resonances in the chamber. The technician would watch the output of a field probe and adjust the amplifier for the proper field strength. At some frequencies, the amp would be set for 3V/m; then when the frequency was stepped to the next level, the field strength would either jump or almost disappear. The amplifier would need quite a bit of adjustment to bring the field back to 3V/m. I'm just wondering if this same effect may be going on; and maybe you don't see it when you dwell on those frequencies. Good luck and please let the group know what you find. Chris Maxwell Nettest From: [email protected] [mailto:[email protected]] On Behalf Of John Woodgate Sent: Thursday, August 18, 2005 1:38 PM To: [email protected] Subject: Re: RF Susceptibility: Sweep v/s spot check "Chileshe, Chris" <[email protected]> wrote (in <97976b56b6309e45bf7378c2c39329ed01a73...@havuksmb01.euro.ad.etn.com>) about 'RF Susceptibility: Sweep v/s spot check', on Thu, 18 Aug 2005: >What is the explanation for this and there are techniques for getting >round this 'problem'? Are you using a real continuous sweep, which inevitably includes sideband frequencies, or a stepping sweep, which doesn't (after the initial transient after the step shift in frequency has decayed)? -- Regards, John Woodgate, OOO - Own Opinions Only. Deadlines are 90% of deadliness. http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [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://www.ieeecommunities.org/emc-pstc This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [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://www.ieeecommunities.org/emc-pstc
