[600MRG] Ground Conductivity -

[Frank Lotito]

" ground conductivity in the U.S. ranges between 0.5 and 30 millimhos (or millisiemens) per meter.  The conductivity of seawater is 5,000 millimhos per meter, resulting in the best propagation of AM signals. "
......
The above was copied from the FCC's recent publication on ground conductivity (https://www.fcc.gov/media/radio/m3-ground-conductivity-map)
................
Obviously, the "gold standard" for ground conductivity is salt water.  I have a question - If one were to lay out 120 equally spaced radials, each a half wave long from the base of a vertical antenna, what would the estimated ground conductivity be compared to "seawater"?  For a more modest radial system, what does it take to achieve a conductivity of say 500 milliohms, which is almost 20 times better than the best ground conductivity in the US, but still one tenth that of seawater?
........
73 Frank K3DZ / WH2XHA