Craig you are right. A helical vertical will be out performed by a top
loaded vertical. The top loaded short vertical will have higher radiation
resistance resulting in a better signal.
Designing and building a top loaded vertical is easy. They work as modeled
in NEC whereas the helical antenna is more of a cut-and-try endeavor.
For everyday use I run a top loaded vertical on top band. Sometimes as short
as 10'. But when contest time rolls around a 130' balloon wire appears,
sometimes flying over the Great Salt Lake of Utah.
Dave WX7G
On Wed, Jul 15, 2009 at 1:16 PM, CRAIG CLARK <jcclark@wildblue.net> wrote:
> This antenna idea is not new. My 1982 edition of the ARRL Antenna Book
> shows
> one on page 10-12. As I remember, the bandwidth is rather low, 10-15 KHz
> and
> it is at best a compromise antenna. At best, the helical antenna is a
> compromise of space versus performance.
>
> Do you have any trees that you can use as an antenna support? For the
> effort, I'd favor an inverted L or one of its iterations over the helical
> design. With a tuning network, this antenna can be quite successful on
> 160-80 and 40 meters.
>
> As for a loop at 8 feet, I would suggest it is not worth the effort. It is
> far too low to give any credible performance on the low bands.
>
> Good luck
>
>
> Craig Clark K1QX
> Radioware
> PO Box 209
> Rindge NH 03461
> 603 899 6957
>
>
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>
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