On 2/6/16 9:47 PM, Jim Brown wrote:
On Sat,2/6/2016 4:22 PM, jimlux wrote:
Using N6LF's formulas I get skin depths around 5-10 meters at 2MHz
(0.005 S/m, epsilonr = 3-10)
You might get 60 feet (20 meters) if the soil is particularly
non-conductive (rock). Dropping the conductivity to 0.5 mS/m gives
you skin depths of 22-34 m at 2MHz
Rock and sand are quite prevelant throughout the west, and pretty much
what we have in the mountains. :)
yes, but.. It's a pretty rare ham shack that sits on a granite outcropping.
And most rock is actually ok from a conductivity standpoint.
http://emgeo.sdsu.edu/emrockprop.html
sedimentary rocks like shales have pretty high conductvity (100 mS/m).
To get down to 0.5, you're looking dolomite, limestone.
The usual granitic sort of stuff also seems to be reasonably conductive,
unless you're looking at shield, unweathered rock.
There's also a frequency dependence.. so looking up a table for low
frequencies (line frequency, etc) might not be a good baseline.
73, Jim K9YC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|