Jim Brown <k9yc at audiosystemsgroup.com> wrote: > Fundamental truths. > 1) The heat is produced in the WIRE, NOT THE CORE. It is the WIRE that gets hot. Heat is produced in both the wire and the core. A lossy core wound with a small number of turns, and subjected to substantial common mode VOLTAGE will overheat. 73, Sinisa YT1NT, VE3EA