[TowerTalk] Vertical "dipoles"

[Jim Jarvis]

Jim Reid wrote:


>I suppose if you were  able to get the lower end of the dipole 
>well above even 1/4 wave length in height,  you would be better off,
> but at WWVH it was far more economical to use the
> ground radials to terminate the high E fields from the
> lower ends of those down sloping fanned radials
> (which,  by the way,  provide the shielding for the
> coax feed which goes up the center of the lower
> portion of the supporting tower structure).

We're in violent agreement.  IF you can control the environment
within 2 wavelengths of the antenna, you can work miracles.
If you cannot, you do what you can.

Clearly, radials under the half wave, center fed vertical will 
improve its efficiency.   But get the low end of the radials high
enough, and it's not a material issue.

See Jim's .jpg.  VERY helpful.

N2EA
Jim Jarvis
jimjarvis at ieee.org