[TowerTalk] Verticals and well pipe grounding

[Donald Chester]

> Also there is an averaging area dimension for the map - I don't remember
> what it is - but any given soil in an area of less than that size,  can vary
> quite a bit from the map values.

> 73 John N5CQ

Exactly.  Look at the map. Some adjacent sections jump abruptly from the lowest conductivity to the highest.
Santa Fe, N Mexico is a good example, where it's 15 on one side of the line, and just to the north across
the boundary, it's only 2. See section 15w.jpg on the FCC map.
 
You know the actual contours would rarely, if ever, precisely follow the boundaries shown on the map,
jumping abruptly from low conductivity at one point, to high conductivity just a few feet to the other side of the
line.  Those maps, based on random samples, are virtually useless for predicting the soil conductivity at any
specific site location. They might be somewhat useful as a preliminary guideline, but no substitute for actual
measurement.

Don k4kyv