Hi Alex. Suggest you contact Polyphaser Corporation who are the experts in lightning protection. www.polyphaser.com 73, Bob, K3GT -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com Search: http://www.contesting.com/km9p/search.htm