[TowerTalk] Vertical in the swamp

[Jim Lux]

Carrington, Walter wrote:
> Is swamp water conductive?
> Fresh water swamps have a lot of stuff suspended or dissolved in the water. The conductivity might be much higher than pure water.  
> A quick google:
> Great Salt Lake = 158,000 uS/cm
> Salt water is about 50,000 microSiemen/cm  (uS/cm)  
> Atlantic Ocean = 43000 uS/cm
> Drinkable water -- less than 3000 uS/cm  (and you'd prefer <1000 )
> Irrigation water -- 3000 to 6000 for  salt tolerant plants.
> Lake Mead = 850 uS/cm
> Lake Superior = 97 uS/cm
> Soil conductivity in New England = 10 to 20 uS/cm  (Map ARRL Antenna Handbook).
> Deionized water = .05 uS/cm
> "Fresh" water swamps =  250 to 37000 by one Australian study,  but conditions were strange there (the 37000 was almost dry,  all were drying out).
> My guess for swamps = 250 to 3000 
> 


For the area right in the neighborhood of the antenna (say, within one 
antenna height), the conductivity is important.  Farther away, it's the 
relative permittivity (dielectric constant) that's more important, and 
water, fresh or salt, is HUGE (e.g. 80ish) compared to almost anything else.






>>From what I can find online,  your conductivity ought to be 10 to 100 times mine.
> It ought to be more conductive than Lake Superior for sure, i.e., substantially better than a clean lake.
> If your swamp gets drier seasonally the conductivity should go up when it's drier but still liquid.
> 
> These numbers make it look like a fresh water swamp will be better for radio than almost all soils and most fresh water lakes but not as good as salt water.
> 
> I wonder if the swamp at the bottom of my hill helps on 2 meters.
> --Walter, K1CMF
> _______________________________________________
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