Towertalk
[Top] [All Lists]

Re: [TowerTalk] How Helically Wound Verticals Really Work (was : Vertica

Subject: Re: [TowerTalk] How Helically Wound Verticals Really Work (was : Vertical dipoles)
From: Steve Hunt <steve@karinya.net>
Date: Fri, 20 Nov 2009 08:53:30 +0000
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
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
>   

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>