On 4/24/2011 4:21 PM, Rick Karlquist wrote:
> It is difficult to feed a vertical dipole in the traditional
> way in the center without the feedline affecting the pattern.
Rudy Severns, N6LF, figured out a way to end feed it, and I expanded on
it. I built my version and hung it from a pulley high in a redwood,
with the top about 110 ft above ground. It works, but when I compared it
to my horizontal dipoles, the dipoles were ALWAYS a couple of S-units
stronger. Before I built it and hung it in the tree I also modeled it in
NEC.
See my power point on Coax Chokes for photos and details of my feeding
method and printouts of the modeling results. On the air comparisons
correlate quite well with the model predictions.
73, Jim K9YC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|