You probably have a common impedance problem and not a field coupling problem, this is due to the fact that your coax cable share the same ground reference. Clayton Paul explains the details of the effect in his book 'Introduction to Electromagnetic Compatibility'. At low frequencies you can draw the equivalent circuit of a multiconductor transmission line with a lumped impedance assigned to each signal wire and the shields, the impedance of the common ground will cause voltage to be coupled from an active line to a quiet line. This can be easily calculated based on basic circuit theory. Joachim -- - -- Joachim Mueller EMC/SI-Engineer, W.L.Gore & Associates Nordring 1 91785 Pleinfeld Germany Phone: +49 9144 6016368 Email: joachim_mueller@xxxxxxxxxx C Deibele <deibele@xxxxxxx> To: jeff.w.loyer@xxxxxxxxx Sent by: cc: si-list@xxxxxxxxxxxxx si-list-bounce@fre Subject: [SI-LIST] Re: Coaxial Cable crosstalk elists.org 05.02.02 16:21 Please respond to deibele "Loyer, Jeff W" wrote: > > ok, I'll take the bait... > > Isn't the crosstalk between 2 coax cables zero? > > Jeff Loyer Bait? Bait? Come come Jeff.... <smile> In a perfect world, the crosstalk is zero. In a real world, however, there is crosstalk, unfortunately. While the crosstalk is small, this may or may not impact you depending on the signal levels that you have. Imagine the following scenario: You have a busbar, that is switched on/off and 50 KHz, 2000 Amps. You have a piece of coax laying near the busbar, that has 50 uV signals on it. What do you think would happen to the signal on the coax? I would bet in this case that the coax would have some signal from the busbar on it. See what I am driving at? Craig ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu