[TowerTalk] Verticals and well pipe grounding

[john at kk9a.com]

Interesting map. I am in the 4 millimhos per meter area. Fresh water areas
like the Great Lakes is only 8 and there are some 30 millimhos areas
scattered around the center of the US.

John KK9A

Re: [TowerTalk] Verticals and well pipe grounding
from [Jim Brown]	[Permanent Link][Original]
To:	towertalk at contesting.com
Subject:	Re: [TowerTalk] Verticals and well pipe grounding
From:	Jim Brown <jim at audiosystemsgroup.com>
Reply-to:	jim at audiosystemsgroup.com
Date:	Mon, 8 Feb 2016 09:17:21 -0800


https://www.fcc.gov/media/radio/m3-ground-conductivity-map

On this page is a link to a 6.8 MB zip file which contains a grid of 8.5-in
x 14-in pages that are sections of the full map. The contours are fairly
rough, with a factor of 2:1. This map is fairly old -- it seems quite close
to the one I worked with in Pete Johnson's consulting office in 1961. My
guess is that it does not show the poorer ground conductivity of developed
population centers described in the soil characteristics for NEC.

N6LF shows a procedure for measuring soil characteristics on his website,
and it's been one of those things that W6GJB and have had on our list of
things to do for several years.

73, Jim K9YC