The 15th edition, ARRL Antenna Handbook, cites ranges for
conductivity:
Poor soil 1-5
milliseimens per meter
Average soil and fresh water 10-15 milliseimens per
meter
Very good soil 100 milliseimens
per meter
Salt water 1000
milliseimens per meter
<<
I don't know where the Handbook got that data.
Salt water is generally accepted at 5000 mS/m. Always has
been, and still is as far as I know. All my BC conductivity
charts show it in the range of 5000mS/m.
The Great Lakes with ALL their pollutants are 8mS/m at 1
MHz. We measured about that amount in BC proofs.
Uncontaminated fresh water would be much worse in
conductivity, probably a few mS/m.
Very good soil is considered to be around 20-30mS/m, not
anywhere near 100.
The best soil we found around Ohio was near 35mS/m in the
old Black Swamp. It was an acidic sandy loam nearly
saturated with water.
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