[TowerTalk] Fwd: Grounding of tower

[Jim Lux]

On 5/10/13 9:15 AM, Jim Brown wrote:
> On 5/10/2013 8:58 AM, George Dubovsky wrote:
>> In the case of a radial system on or just below the surface of the earth,
>> one or many ground rods connected anywhere to the rf ground system should
>> not hurt,
>
> Please remove the phrase "RF ground system" from your vocabulary -- it
> is a false concept, and leads to confusion.
>
> Rudy Severns, N6LF, has done a lot of work studying radial systems for
> verticals, especially for the lower bands.  Rudy has shown that an earth
> connection can significantly degrade the performance of an elevated
> radial system. I suspect he might agree that adding an earth connection
> to the feedpoint of a dense on-ground radial system would not hurt, and
> radials connected a grounded tower certainly have that condition . Earth
> connections elsewhere in the radial system are a bad idea, because they
> disturb (in a bad way) the current distribution along the radial. Rudy's
> published work does a great job of explaining why.
>
>

This was also an observation when they were validating NEC3/NEC4.  They 
modeled worse performance with a set of radials plus a ground rod than 
just the radials alone.  They were kind of surprised, so they went out 
and built a test and verified that it is real.