> From: K4IA@aol.com
> Sent: Monday, March 18, 2002 9:21 AM
> To: BarryS@core.com
> Cc: towertalk@contesting.com
> Subject: Re: [Towertalk] Antenna Suggestions Wanted!
>
>
> If you top feed the inverted L, you don't need/want radials. Check out
> Cebik's articles on the inverted L. <A
> HREF="http://www.cebik.com/gup25.html";>http://www.cebik.com/gup25.
> html</A> and others at the same site.
ANY vertical antenna, will perform better with a good radial system.
Any vertical antenna in close proximity to ground will have a field
that interacts with the ground such that any improvement in ground
conductivity in the high field area (generally 1/4 wave radius of the
bottom of the antenna) will improve system efficiency.
As the feed point is raised above ground, the area of critical loss
increases in diameter (and moves out). Since the field intensity
is a square law function, interaction with ground decreases as the
feed point is elevated. Work by N7CL and others shows that losses
start to get down to a reasonable level at heights between 1/8 and
1/4 wave and reach a limit at about 1/2 wave elevation.
Still, if one can't install a "broadcast quality" ground system, use
the best that time and budget allow. Don't believe the old wives'
tales about certain "magic" antennas.
73,
... Joe, K4IK
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