Gary McInturff wrote >> I have to get a UTP Ethernet connection out of a semi-anechoic chamber. There no anti-chamber so any unfiltered cable routing opening is a major leak because of the opening and the induced noise on the cable itself. Since Ethernet signals don't like to be filtered. I'm considering two options - neither of them make me real happy.
1) Find, if one exists, some sort of metallic RJ-45 bulkhead transition connectors and mount that into the transition panel. I've seen the plastic versions for inter-connecting Ethernet cables, but the were neither metallic nor bulkhead mounted. 2) Make an air dielectric waveguide out of foot or so ½ inch metal pipe and attach that to the transition panel and route the cable through the "wave guide" The opening itself even at ½ is larger than 18 GHz upper test frequency, but the width of the wave guide buys me some attenuation - and I don't expect to see much in the way of ambient up that high anyway. << First off, abandon any idea of snaking the wire through the waveguide transition; putting a wire in a waveguide makes a coax out of it; anything n the wire will still be there outside the chamber. (You KNEW that, right?) Best shot; convert to fiber to get out of the chamber. Do it right first and you won't have to do it over again. You COULD transformer isolate the Ethernet, and pass the signal through a common mode choke -- bifilar wind magnet wire for a 100 ohm transmission line, or wrap the UTP on a larger toroid etc. Use STP outside the chamber to give you a "free" parasitic capacitor for the CM choke to work with. Cortland KA5S - 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 ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
