[TowerTalk] antenna height

[Bill Turner]

ORIGINAL MESSAGE:

On Tue, 28 Nov 2006 17:22:06 -0000, "Merlin-7 KI4ILB"
 <merlin-7 at sc.rr.com> wrote:

> I know that your antennas need to be at least 1/4 wave from the ground but do you lose anything or not gain anything by going to to high?
> If so please explain...
> Thanks
> Joe

------------ REPLY FOLLOWS ------------

Changing the height affects the optimum "takeoff angle". Antennas
relatively low to the ground radiate most of their power straight up
or nearly so, but that can be a good thing on the lower frequencies if
you want mostly local contacts out to a few hundred miles or so.

As you increase the height up to one, two or a few wavelengths, the
takeoff angle comes down closer to the horizon and thus is good for
long-distance communication. 

A good way to learn about this is to get a copy of EZNEC and set up
different antenna models. A few hours spent with EZNEC is worth days
of discussion on the internet. There is a demo version available at

www.eznec.com

Try it out - it's great fun as well as a great learning experience.

Bill, W6WRT