Have you considered a coaxial dipole design? It can be made several ways.
The most popular is to fold back the shield 1/4 wave over the outer jacket
of the coax leaving 1/4 wave center conductor. The antenna is end fed, no
matching (it still needs the 1:1 balun, loop, or ferrite beads to keep the
radiation from following the jacket). It can be made by running the coax
through the center of a piece of copper or aluminum tubing, or using copper
braid. They work well as vertical or horizontal antennas and it will fit
your requirements below.
Good luck
Buck
N4PGW
> -----Original Message-----
> From: towertalk-bounces@contesting.com [mailto:towertalk-
> I want to end-feed a half wave vertical so I can get a nice low angle of
> radiation. The base of the antenna would be about 0.05 to 0.10
> wavelengths above ground. It looks like the antenna impedance will be
> around 4,000 ohms. I would prefer not to use tuned circuits or stubs as
> I would like the device to work over a 2:1 frequency range. (No, I'm
> not expecting the antenna to be a half wave over a 2:1 frequency range!!
> I would have 2 different antennas to choose from.) Power level is 200W.
>
> 73 de Jim Smith VE7FO
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|