At 09:13 PM 2/1/02 -0500, Chuck wrote:
>
>In getting back to the basics, I submit that at heights over 4 to 6
>wavelengths above ground, the antenna is in "free space" and
>that's why the "nulls"are filled in. Also, at these heights, in free space
>means you have no gain from ground reflection, so they are 5-6 db
>down from lower antennas. How does one define free space? How
>high above ground would you have to be to be considered in this category?
A lot higher than 4-6 wavelengths. I ran a 10m yagi in EZNEC at 200 feet
above ground, and both the deep nulls and reflection gain were still fully
evident.
73, Pete N4ZR
Sometimes a tower is
just a tower
________________________________________________________________________
Where do you get ICE bandpass filters & beverage matching boxes? The
same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
-----------------------------------------------------------------------
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|