That doesn't look too good. Start with finding a preamplifier (10-20 dB). Be careful, too much gain will destroy your dynamic range. Check receiver settings too. Too high amplitude reference level may invoke IF atten that you are not aware of. The noise floor 10 dB below limit as you mention should be the goal,
Ari > -----Original Message----- > From: ext Russell [mailto:r....@totalise.co.uk] > Sent: 27 February, 2002 12:06 > To: emc-pstc > Subject: Screened Room Ambient Scans > > > > What levels would one expect to see from a scan (30MHz to 1 > GHz) within a > screened room prior to testing for emissions (UUT switched off). > > I'm looking at an ambient scan starting at 32dBuV/m @ 30MHz, > dropping to > 18dBuV/m @ 70MHz then gradually (with small peaks and > troughs) rising to > 41dBuV/m @ 1GHz. > > Particularly at 30MHz and 1GHz this is less than 10dBuV/m > below the EN55022 > cl. B limits. Does this (high?) noise floor affect the final > measurements? > > Thanks in anticipation. > > Russell. > > > ------------------------------------------- > 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: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > 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" > ------------------------------------------- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org 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"
