Some of that data for two types of coils is on my web page at http://www.k1ttt.net/technote/airbalun.html, it might give you some idea of what you are looking for and some of the things you must consider. David Robbins K1TTT e-mail: mailto:k1ttt@arrl.net web: http://www.k1ttt.net AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net