Hi Well at the risk of being burnt at the stake I believe that: When carrying out an automatic sweep some EMC test software does not allow the power meter time to measure the power level correctly. (The larger the transition the longer it will take for the power head to level and this isn't taken into account) and as time is money everyone wants the test to run quickly! The result is overshoot and undershoot of the actual level and I guess that this may be what you experience with this pass/fail issue between manual and automated sweep tests. The big transitions occur when reflections are experienced in the room. I found putting boards covered with foam absorber helped to disperse the RF before it was reflected off the offending wall even though it was ferrite lined. Or even testing at an angle to the walls helps. I hope this isn't too much like heresy Cheers Rich Richard Jones EMC Project Officer Wolfson Centre for Magnetics Cardiff University Queens Building Newport Road Cardiff Wales, UK CF24 3AA Tel: +44 (0) 29 2087 5936 Fax:+44 (0) 78 9819 9422 URL: http://www.WolfsonEMC.co.uk ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/
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