[TowerTalk] Good vacation antenna

[Wes]

I assume that you're referring to the Boothe article.  I've only found part 1 of 
that, since ARRL in its infinite wisdom prevents download of the piece.  But he 
didn't need to measure this, it can be modeled; the EZNEC help file says: "The 
currents at the ends of real loading coils are often substantially different 
because of radiation and/or physical length. When this occurs, the EZNEC load 
model, which has equal currents at the two terminals, does a poor job of 
representing the coil, and considerable inaccuracy can result. Whenever 
possible, a helix rather than a load should be used to model a loading coil."

I used a distributed coil model in a paper about short inductively loaded 
antennas that I wrote 20 years ago and posted on the Rec.Radio.Amateur.Antenna 
newsgroup.

Wes  N7WS


On 7/4/2025 11:30 AM, Jim Brown wrote:
> On 7/4/2025 8:39 AM, Wes wrote:
>> I "built" a model of a vertical in AutoEZ and used EZNEC Pro/2+ V 7.0 running 
>> the NEC 5 engine to do the computations.
>
> All good, but -- one of the things that long QEX piece showed is that EZNEC 
> doesn't correctly model inductive loading! They did this by comparing the 
> modeling result with measurements of built antennas.
>
> 73, Jim K9YC
>