[Elecraft] OT: Ground rods and concrete

[Rick Dettinger]

Thyir’er we go!

73,
Rick  K7MW





> On Apr 18, 2017, at 6:01 PM, Matt Zilmer <mzilmer at roadrunner.com> wrote:
> 
> Time to update that list of frequently misspelled words. It is very long, but also distinguished.
> 
> How about it's versus its?  The first is a contraction, and the second is a possessive.  I think, from experience, that this is the single most common spelling error that I see from English-first writers.
> 
> /me ducks.  I'm SURE this is off topic.
> 
> 73,
> 
> matt W6NIA
> 
> 
> On 4/18/2017 5:03 PM, Randy Lake wrote:
>> This has been bugging me for a while and I am now in a mindframe to comment.
>> Lightening:
>> light·en·ing
>> ˈlītniNG/
>> *noun*
>> 
>>    1. a drop in the level of the uterus during the last weeks of pregnancy
>>    as the head of the fetus engages in the pelvis.
>> 
>> Come on !!
>> 
>> Randy
>> N1KWF
>> 
>> 
>> On Tue, Apr 18, 2017 at 7:39 PM, Ken G Kopp <kengkopp at gmail.com> wrote:
>> 
>>> I was the first to use the term "exploding tower base" in this discussion.
>>> The term "exploding" was probably not correct.  As several others have
>>> phrased it, an instant expansion of steam is more correct. Concrete is
>>> never totally "dry" in the context of this conversation.
>>> 
>>> I witnessed lightening blowing apart the two tower bases I spoke of in
>>> person, directly, and in real-time. It happened in the mid-sixties at the
>>> St. Petersburg, FL Coast Guard base.  As someone else has mentioned;
>>> the Tampa Bay region has the highest incidence of lightening in the
>>> Western Hemisphere.  To the one of you who accused my of lying ...
>>> I was there ... you weren't.
>>> 
>>> At the time I was an ET aboard the USC&GS (Now NOAA) Oceanographic
>>> Survey ship Hydrographer/WTEI and we were in the area deliberately
>>> attracting lightening with balloon-hoisted cables.  I -do- know something
>>> about the infinite uncertainty of lightning.
>>> 
>>> I'm a retired electric power company two-way radio tech and have probably
>>> dealt with more types of towers than most of you.  Large electric
>>> transmission
>>> line towers are almost always set on four concrete piers, and are grounded
>>> with (usually) copper straps cad-welded to each tower leg and connected to
>>> ground rods a bit away from the cement.  Each of us can search long enough
>>> to find "facts" that support our various positons, especially on today's
>>> Internet.
>>> 
>>> Here in the mountains of the West ... as well other regions ... finding and
>>> maintaining a "good" ground at a radio site atop a mountain can be a
>>> "challenge".  It's almost never done with ground rods.  My power company
>>> employer has several hundred mountain-top microwave and/or radio sites.
>>> Been there, done that, as they say.
>>> 
>>> One responder spoke of fitting a copper pipe with a garden hose fitting and
>>> "flushing" it into the ground.  That works very well, and is how some of my
>>> 14 grounds are installed.  It helps if the downward end is partly
>>> flattened, BTW.
>>> 
>>> A much bigger problem overall than lightening is water collecting in tower
>>> legs,
>>> especially in climates where it can rust (undetected) from the inside and /
>>> or
>>> freeze and split one or more legs.  There's an accepted way to avoid this.
>>> 
>>> 73!
>>> 
>>> Ken Kopp - K0PP
>>> 
>>> 
>>> On Apr 18, 2017 at 4:30 PM, <w5sum at comcast.net> wrote:
>>> 
>>>> some 40 years ago, maybe longer I put up a 50' rohn 25G tower. Dug the
>>>> hole
>>>     and set the tower base in it alone with a 12' 3/4" ground rod and
>>> poured the
>>>     cement, left about 6" of ground rod protruding. I bonded to that rod
>>> and grounded
>>>     the tower. 3 years later I had a huge lightning strike on my tower and
>>> yes.. it cracked
>>>     that base.
>>> 
>>>     never again
>>> 
>>>     Ronnie W5SUM
>>> 
>>>> ______________________________________________________________
>>>> 
>>>> 
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>> 
>> 
> 
> -- 
> "A delay is better than a disaster."
> -- unknonwn
> 
> Matt Zilmer, W6NIA
> [Shiraz]
> 
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