In message <9d04b979323dcd428297dda95108893e0120c...@bb-corp-ex2.corp.cubic.cub>, dated Mon, 16 Jun 2008, "Price, Edward" <[email protected]> writes:
>For a standard of comparison, maybe I could use the definition of a >good conductive joint as one being less than 0.0025 Ohms. If I assume >that the radiated leakage is proportional to the joint resistance, then >a 1 Ohm value is 400 times higher than a "good" joint. That would imply >that the leakage would be 52 dB greater than the "good" joint cable. > >Naahh, can't be that simple! Your frequency range is 10 kHz to 5 MHz. The joint is an antenna about 0.1 mm 'long'. It isn't going to radiate significantly. What is more likely: - the resistance of the joint adds to the impedance of the cable shield. If the interconnection is unbalanced, this increases the disturbance voltage (picked up on the shield either via capacitive or magnetic coupling) injected into the circuit. If the interconnection is balanced, the increased disturbance voltage appears as a common-mode signal, so may or may not have a significant effect; - IF the cable is long enough (but it needs to be very long), the increased voltage on the shield due to common-mode conducted emission >from the internals of the equipment may result in an increase in significant radiated emission. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Either we are causing global warming, in which case we may be able to stop it, or natural variation is causing it, and we probably can't stop it. You choose! John Woodgate, J M Woodgate and Associates, Rayleigh, Essex 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/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: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
