So I left a thread of posts about this new coax I had made, trying to understand its electrical characteristics such as velocity factor and so on... Then I had an occasion to exchange emails with the MFG asking what the capacitance was per foot. The answer was something like 30pF per foot. The operating frequency is 49MHz. When I use the same VNA I posted about last time, the capacitance at 36" @ 49MHz rose to 5.1nF before it flipped to inductive! Why isn't the capacitance per foot exactly that? Why isnt it linear? One would think if a MFG told you our new coax design had 30pF per foot that three feet would yield 90pF, not 5100! Whats going on? By the way, this new coax is being measured open ended as this config presents an issue so that's the way we are testing. The same 36" coax lead terminated with a 50 Ohm terminator yields about 10pF@ 36"! Makes no sense to me whatsoever. The dielectric constant of this stuff is very close to 2.03 with a Vf of .7 Anybody understand why my VNA single port S-Param measurements are so wacky when it comes to this coax? I've tested multiple assy's on two different VNA's and get the same data. Thanks.