Owen Duffy wrote:
I have constructed an NEC model of an 80/40 dipole using bootstrap coax
traps. I have generated a helix of GW elements for the RG58C/U coax coil,
and use NT cards to model the coax interior.

Plain conductors are loaded with copper conductivity.

I am grappling with approprate conductivity for the outer surface of the
coax coil, thinking that it must be greater than copper because of
proximity effects and braid effects. I have initially tried loading those
segments with conductivity of one tenth of copper... but I don't expect
that will make the RF resistance tenfold.

With those numbers, the loss in the interior of the coax is more than
half the total loss.

Has anyone experience or thoughts on an appropriate way to load the
conductor representing the outer surface of the coax coil forming the
trap?


Try changing the resistivity by a factor of 2 or 10 and see if the model
results change significantly. It might be a non-issue.