[HCARC] One last Question

[curtiswe at ktc.com]

The over simplified, not quite what really happens but useful for illustration answer is; that the ground provides the missing half of an antenna as a mirror image. Think of a pencil held perpendicular to a mirror, it looks twice as long as it really is. 

What actually happens is that the ground provides a path for the return currents in an incomplete or electrically  short antenna (compared to a half wave dipole in which the currents are returned through the other half).  

The conductivity of the ground plays an important role in determining the efficiency of such an antenna. Most soil is not all that conductive. This can be improved by adding a conductive screen such as radial wires, on or just under the surface.   

That doesn't cover all of it but I hope it helps.
Sent from my BlackBerry® Smartphone by WCW

-----Original Message-----
From: "Gary and Arlene Johnson" <qltfnish at omniglobal.net>
Sender: hcarc-bounces at mailman.qth.net
Date: Mon, 27 Aug 2012 13:18:46 
To: <hcarc at mailman.qth.net>
Subject: [HCARC] One last Question

What does it mean to "work an antenna against ground".  This is another one of those seemingly innocuous statements I see in the antenna book.  It assumes that everyone knows what "working against a ground" means.  Is it the same as grounding an antenna??  If all antennas are to be grounded, why make the statement??

You usually see the statement in context like this "this antenna can be used on 160 meters if worked against a ground".

Gary J
N5BAA
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