[TowerTalk] Vertical and radials

[Robert Harmon]

I love your perfect QTH description.   A hill of salt water, sloping gently in all directions.   hihihi

I am having trouble finding ground conductivity fro my area in the north San Francisco Bay Area.  Napa county.
Looks like my area shows a number 8.  Where is he chart to find out what this means in conductivity ?
Wish I could find a map that I could drill down closer to my QTH.  I know it is pretty good right now, we have had 
lots of rain the last few weeks.

Bob
K6UJ



> On Jan 22, 2022, at 3:58 AM, John Langdon <jlangdon1 at austin.rr.com> wrote:
> 
> The other thing that K5IU was clear about is that the ground under the
> antenna is the dominant factor in performance regardless of the radials you
> use.  
> 
> 
> 
> If you have really low conductivity soil under the antenna, even if you
> mount a vertical on a 1/4 wavelength radius copper disc, essentially an
> infinite number of buried radials, you are going to get poor performance.
> Elevated radials will be as good or better in that situation, and are less
> work, but a high dipole, over poor soil, will be equal or better.
> 
> 
> 
> If you have really high conductivity soil, a modest number of buried radials
> or a set of 4 1/8 wavelength elevated radials tuned with an inductor will
> probably give you good performance.
> 
> 
> 
> If you are over salt water, a single resonant radial will work very well.
> 
> 
> 
> BTW the ground conductivity maps most of us have access to, like
> https://commons.wikimedia.org/wiki/File:United_States_Effective_Ground_Condu
> ctivity_Map.png , are from data averaged over a large area  and any given
> location within an area on the map may vary widely from the average. The
> perfect QTH is a hill of salt water, sloping gently in all directions.
> 
> 
> 
> 73 John N5CQ
> 
> 
> 
> 
> 
> 
> 
> 
> 
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