[TowerTalk] [Bulk] Re: Tower grounding connections and foundation

[Mike Reublin NF4L]

My Ufer ground megged at 4 ohms. No ground rods.
73, Mike NF4L


> On Aug 8, 2015, at 11:02 AM, Paul Christensen <w9ac at arrl.net> wrote:
> 
>> "Then there is the "default" - 10 ohms - maybe one ground rod and 18 gauge
> wire?  Hilarious!
> 
> Not too hilarious on the day we were driving 24 ft. rods with a hammer drill
> just to get under 10-ohms in the sandy soil of North Florida.  Repeated 4
> times to get below that target.   Two 8. ft rods spaced 16 ft. and connected
> together with #2 copper gets you to maybe 50-60 ohms here.  
> 
> I can see why the G spec also requires 10-ft rods.   We saw an asymptotic
> effect when adding more and more 8 ft. rods.  The 24 ft rods allowed us to
> reach the goal line.  We went from about 30 ohms with many 8 ft. rods to 10
> ohms with just one 24 ft. rod.  The end result was about  5 ohms as measured
> with a clamp-on earth tester with the four 24 ft. rods placed at the shack
> EGB, each of the two tower bases, and in between each tower.  
> 
> That said, I do agree there's often a lot of "spec polishing" in the trades.
> For example, why is that a 3/4" PVC emergency drain pan line for my hot
> water heater was fine in 2001, but then local code increased it to 1" the
> next time it was replaced?  Then code required 1-1/4 just recently with the
> last heater change.  Just how hard is it to figure how big is a "big enough"
> line for a drain pan?  In 4-5 years, will that change to 1-1/2"?
> 
> Paul, W9AC
> 
> 
> 
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