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

[jimlux]

On 4/29/20 12:31 AM, David Gilbert wrote:
> 
> Agree on all of that, which is why I agreed it isn't a dominant effect. 
> And of course you and K6STI have a good point about the additional wind 
> loading of mid-element coils.
> 
> Every commercial coil loaded shorty-40 antenna that I know of puts the 
> coils out on the elements, though, so I suspect it may be worth the 
> bother if done right.
> 
> 73,
> Dave   AB7E
> 

I suspect that it's driven by 3 things:
1) commonality of parts for different models of antennas (i.e. you only 
need one kind of boom/element clamp or other aspects for manufacturing 
convenience)

2) mechanical design (previous comments about cantilever loads, and the 
general complexity of attaching stuff)

3) buyer preference - product differentiation (the buyer likes how it 
"looks" or is influenced by other factors)

RF performance (particularly forward gain) is probably a wash for 
"practical" designs, and most hams aren't going to buy one of each and 
evaluate whether the side and backlobe shapes are "best" for their 
operating style.