[TowerTalk] FW: Tower Grounds

[Grant Saviers]

When I upgraded my tower grounds, I bought rods at a commercial 
electrical supply house and Home Depot.  The 5/8" rods looked a bit 
small and a caliper showed them undersized.  I then checked some 1/2" I 
had on the shelf, and they were undersized also.  I found this article

http://www.galvanelectrical.com/pdf/groundrodmarkingcompliance.pdf

I have never seen a "code compliant" stamped ground rod.  Also, I have 
no way to measure Cu plating thickness, but would assume it was cheated 
on as well.  Probably they all came from China where 1" = 19mm.

One thing I did learn in measuring the results was that #2  wire 
contributed significantly to reducing the DC resistance of a leg (35' #2 
plus 2x 8' x "5/8" rods). (some earlier rods were #8 connected).  Since 
#2 is 0.258" diameter (mine is USA #2) and 5/8 rods were about 0.58" the 
circumference ratio is 2.24.  So 35' of #2 solid earth contact area is 
about equal to 2x 8' x 5/8- rods.  Of course buried 6" the field 
distribution is a bit odd, but at DC it helped to get near to the 
Motorola 5 ohm target.  Also, I'm confident the #2 copper will be there 
after the copper flash on the rods is long gone.

Additional reasons to use a Ufer.

Grant KZ1W