George, Mitchell Instruments carries several wire mappers/sorters. Here's one: www.mitchellinstrument.com/cgi-local/shop.pl/SID=1057423835.14643/page=c587c.htm 73, Eric Lemmon WB6FLY George Shaw wrote: Does anyone know of a hardware device that will allow me to attach a tone or digital ID sender at one end of a cable and that ID can be picked up at the far end of the cable? George Shaw MI3GTO