>
>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com [mailto:towertalk-
>> bounces@contesting.com] On Behalf Of Mark Robinson
>> Sent: Sunday, May 13, 2007 9:17 PM
>> To: TowerTalk@contesting.com; Jim Garland
>> Subject: Re: [TowerTalk] Rohn BPC25G
>>
>>
>>
>> >
>> >>
>> >>Dont ever put a ground rod in the concrete base. A lightining strike
>> >>can
>> >>easily explode the concrete.
>> >>
>> >>Carl
>> >>KM1H
>> > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>
>> > I've heard that for years, but I read recently (I think on the
>> > Polyphaser website, but I could be wrong) that that is an urban myth
>> > and that grounding a rebar cage is actually very desirable. Does
>> > anybody know someone who's actually exploded a concrete base?
>> >
>> > Jim W8ZR
>> >
>> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>
>> Connecting the rebar together and out of the top of the concrete as an
>> addition to the ground system is called a ufer ground. This uses the
>> conductivity of the damp concrete to couple to the soil. Do a google
>> search
>> on ufer ground
>>
>> I believe that you want to avoid having the rebar sticking out of the
>> concrete block into the soil underground as this is a direct path into
>> the
>> soil.
>>
>>
>> Mark N1UK
> --------------------------
> You don't want anything sticking out of the concrete either rebar or a
> ground rod. Not because it is a lightning path but because it will corrode
> (rust) and the corrosion will work its way up into the concrete and that
> will crack the concrete.
>
> It is fine to use the rebar inside the concrete as an auxiliary ground for
> the tower but it should all be tied together in the concrete so that there
> is no arcing from one piece to another in there.
>
> It is just as important to build the concrete so that no water accumulates
> around any pier pin or j bolts sticking out of the top too. If they rust
> down into the concrete you will have the same problem with the concrete
> cracking.
>
> 73
> Gary K4FMX
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
How do you connect to the rebar inside the concrete?
Mark N1UK
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