Original poster: "Richard W. by way of Terry Fritz <twftesla-at-qwest-dot-net>" <potluck-at-xmission-dot-com> Hi list, Was wondering. Power transmission lines, before a substation, can carry from 100Kv to more the 600Kv. So why no corona? Seems we battle corona quite a bit at much lower voltages. <shrugs> Rick W. Salt Lake