Mike, The ARRL Antenna Book gives Vf as 0.81 for 75 ohm, aluminum jacket hardline, foam dielectric. 73 Don K5AQ -- FAQ on WWW: http://www.contesting.com/FAQ/towertalk Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com