[Lowfer] antenna current

[Bill Ashlock]

>Of the three goals, only one can be reasonably achieved in back yards at 
>LF,
>that is to reduce the dielectric losses close to the antenna.

>*The ground system is simply not long enough to provide a low impedance 
>return for much
>of the antenna current*.

John, I respectfully disagree with this point. The examples you gave in the 
text of your posting relate to full sized AM broadcasting antennas and the 
best radial length comes to >.25WL. I think the basic rule for verticals of 
ALL heights is the that the radials be a little longer than the height of 
the antenna. This makes sense to me because the size of the electric field 
surrounding the antenna is proportional to the actual length of the antenna, 
not the wavelength of use.

I believe that at LF most of the need for a good radial system is to provide 
a return for the electric field to the ground point in the final, thus 
preventing the field from using the lossy soil for this purpose. This has 
little to do with the actual transmission of the wave generated (except it's 
initial amplitutude), which I believe doesn't need a special ground because 
the soil, itself, is sufficiently conductive.

Bill A

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