All, The general consensus is that the emissions specs were derived to "protect" intentional receivers.
ALERT: Be aware that a giant ITE company that has a vested interest in PCs has managed to render the emissions spec. useless. Somehow the FCC allowed FCCB + FCCB = FCCB in CFR47 for component combinations!! For example: If Company A mixes a certified motherboard from company B with a certified video card from company C then Company A can affix the FCC logo WITHOUT testing. The FCC and others freely admit that the resultant mix can fail - I have private emails that such mixtures have FAILED by as much as 20db over Class B!! The FCC have managed to render the emissions test irrelevant and causes the electronics industry to add cost. So much for protection. Thank you Charles Grasso Advisory Engineer StorageTek 2270Sth 88th Street Louisville CO 80027 M/S 4247. Tel:303-673-2908 Fax:303-661-7115 email:[email protected] Web Site: http://www.ewh.ieee.org/r5/denver/rockymountainemc/ -----Original Message----- From: Dave Clark [mailto:[email protected]] Sent: Friday, May 28, 1999 7:31 AM To: 'Lou Gnecco'; [email protected] Subject: RE: History Class ... Doug, I don't know the exact history behind the limits. However, one thing you may want to keep in mind is that emissions limits are based on protecting intentional receivers which have relatively sensitive front ends. Thus driving tight emissions limits from unintentional radiators. Do they need to be as tight as they are? We could discuss for a while. David Clark Spike Technologies, Inc. -----Original Message----- From: Lou Gnecco [mailto:[email protected]] Sent: Thursday, May 27, 1999 9:31 PM To: [email protected] Subject: Re: History Class ... Doug, Some of these limits were based on the field strength that you typically encounter in an urban area. Lou At 01:45 PM 5/27/99 -0700, you wrote: > >Anyone have a clue where the limits (frequency >and amplitude) for CISPR-22 came from? > >For instance ... > >Radiated Limits for Class A at 10 meters > > Frequency Quasi-Peak limits > MHz dBuV > > 30 - 230 40 > > 230 - 1000 47 > > >Why the 40 dBuV/m limit from 30 - 230 MHz? > > >Or any other similar standard limits for that matter? > >Regards, Doug McKean > > >--------- >This message is coming from the emc-pstc discussion list. >To cancel your subscription, send mail to [email protected] >with the single line: "unsubscribe emc-pstc" (without the >quotes). For help, send mail to [email protected], >[email protected], [email protected], or >[email protected] (the list administrators). > > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators). --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators). --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
