[TowerTalk] How Helically Wound Verticals Really Work (was : Vertical dipoles)

[Steve Hunt]

One way of achieving lots of  top "capacity loading" is to stick a 
remotely tuned mobile whip on the top of the vertical. When it's below 
resonance it's capacitive and variable. In the 1970s a local ham 
designed the equivalent of today's "screwdriver" and used it to top load 
a 25ft vertical aluminium pole for 160m. I don't know why I never hear 
this suggested these days.

73,
Steve G3TXQ

Jim Brown wrote:
> YES! The problem, of course, is that you may need both, in which case I 
> would use as much top loading as possible (multiple wires, longer) and add 
> some inductance near the top of the vertical section if needed. This is my 
> gut feeling, not based on modeling. 
>
> 73,
>
> Jim K9YC
>