[TowerTalk] 40m 4el KLM - replacing linear loading with coils

[Jim Brown]

On 4/28/2020 6:50 PM, David Gilbert wrote:
> Whether NEC accurately models the current isn't the point.  You don't 
> need a model to know that if you push the coil out away from the center 
> the portion of the current between the coil and the center is higher 
> than it would be between that same point and the center if the coil was 
> at the center.

Yes, BUT you DO need a model to QUANTIFY how much better (or worse) the 
performance is for variations of a design to answer questions like "Is 
it worth the trouble to do all this?" W6GJB and I spent a lot of time 
optimzing an 80M vertical for portable operation. We used several 
variations of top and bottom capacitive loading combined with several 
variations of inductive loading. None of our designs used a base loading 
inductor, but we did vary their position. There were some designs that 
worked awfully well electrically, but were a problem to build, or had 
issues with wind.

And it's also worth it for what you can learn by going through the 
process.

73, Jim K9YC