[TowerTalk] [NCCC] Dielectric Constant of THHN

[Jim Lux]

Dean Straw wrote:
> Jim:
> 
> EZNEC Version 5 has a default value of 3.5 for PVC insulated wire's
> dielectric constant, with a loss tangent of 0.05. (In EZNEC Version 5, in
> the Wires dialog box, right click on the "Diel C" box to see default
> values.)
> 
> 73, Dean, N6BV
> 

That's fairly high.  Most unfilled plastics are in the 2-3 range PVDF, 
Kynar, is much higher. I have seen numbers for PVC of 3.1 to 3.2

However, you might want to look at
http://wwww.madisoncable.com/CableDesign2.asp

which gives radically different numbers depending on whether it's been 
Irradiated or not.


Given the wide variation, maybe you need to measure it? Or ask the mfr 
of your wire?