Marcel Birthelmer wrote: > On Thu, Jun 17, 2010 at 11:48 AM, John Chung wrote: > >> I am curious..... WHY and WHY is shield cables NOT ALLOWED?! >> >> John. >> >> > > Probably because shielding inevitably causes the issue of where to > ground the shield etc... and if you have different grounds in > different parts of the system, it's even trickier. > Shield on twisted pair need (should) only one end grounded. Applies to Mixing desks with Balanced Microphones or STP for 10/100/1G ethernet. This provides screen and prevents ground loops as the signal is supposed to be differential on the twisted pair only. Coax needs both ends grounded. If the coax has a 2nd *isolated* screen insulated from inner screen, it should only be grounded at one end. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist