[TowerTalk] EZNEC Question

[David Gilbert]

I did some more searching and found a similar discussion on the 4NEC2 
reflector from about 3 years ago.  In it was a link to this article by 
Cebic which seems to indicate that dielectric loading of a conductor 
produces an inductive effect.  If that's the case it makes sense that it 
would have more effect at a current maximum than a voltage maximum.

https://hamwaves.com/wire/doc/Insulated%20Wires:%20The%20NEC-2%20Way.html

I also harkened back to the formula for velocity factor in a coaxial 
transmission line, which is V = 1/sqrt(er), where er = the relative 
permittivity.  That certainly describes the equivalent of an inductive 
effect.

Apparently at age 77 I'm not yet too old to learn ... although that day 
might not be too far off.  ;)

Dave   AB7E

>
>
> On Mon, 27 Jan 2025 20:33:55 -0700, David Gilbert <ab7echo at gmail.com> wrote:
>
> I've been using EZNEC Pro/2 to try to model the effects of dielectric
> loading on a wire antenna ... specifically a full wave loop on 435 MHz.
> I split the sides of the loop up into multiple wires (each with multiple
> segments) so I could individually declare a thick dielectric ... i.e.,
> insulation in the wires table ...  separately for each portion of the
> loop.  To my surprise the loading effect seems to be greatest at or near
> current maximums, not at voltage maximums where I would have presumed
> the electric field would have the most effect.  This has me greatly puzzled.
>
> Any thoughts?
>
> Dave   AB7E