So the text books say....
However some of this is counter-intuitive and very counter-empirical.
Best regards - Brian AF4K
> On Jan 19, 2015, at 12:17 PM, Kelly Taylor <ve4xt@mymts.net> wrote:
>
> In most cases, RF ground is a fallacy. The right length of conductor can
> make it so that there's zero difference RF-wise between having it connected
> and having it not connected to the ground rod. A ground conductor starts
> rapidly losing effectiveness RF-wise at one-tenth a wavelength (about 6' on
> 10m) and longer.
>
> Also, as part of an antenna system such as a vertical, a ground rod (for RF
> purposes) is next to useless. (Important for lightning protection, yes, but
> not for RF.) Radials are the way to provide RF current return: a ground rod
> is mostly very well insulated from picking up return currents.
>
> Dry soil has got to be less conductive than moist soil. I would think what
> that means is multiplying the number of ground rods to make up for the lack
> of conductivity, and perhaps encasing the rods in concrete or bentonite to
> maximize whatever conductivity there is. You don't have to have the rods
> vertical, either. You could lay them in trenches, and for concrete
> encasement, you'd treat the ground rod much like you would rebar, suspending
> it in the concrete during the pour.
>
> 73, kelly
> ve4xt
>
>
>
>
>> On 1/19/15 10:45 AM, "Ken" <wa8jxm@gmail.com> wrote:
>>
>> It seems to me that the ground above my rock layer (@ 36-40²) gets really
>> dry
>> during the summer. Does that dry dirt have enough conductivity to be useful?
>> I do not know the answer to that question.
>>
>> Are there different answers depending on why we have the ground rod? (RF
>> ground, power line ground, or lightning protection)
>>
>> Ken WA8JXM
>>
>>
>>> On Jan 19, 2015, at 12:53 AM, Kelly Taylor <ve4xt@mymts.net> wrote:
>>>
>>> It seems to me a valid question to ask on this thread: Do you gain anything
>>> by, for example, drilling a hole to get a ground rod deeper?
>>>
>>> If you think about it, the answer might not be so simple.
>>>
>>> The point of a ground rod is to maximize electrical contact with the ground.
>>> If you have to drill 48 inches of an eight-foot rod and don't employ some
>>> kind of conductive filler (concrete, bentonite, etc.) to bond the rod to the
>>> rock, how much better off are you than just putting in a 48-inch rod? Even
>>> if you do use bentonite, is rock a good connection?
>>>
>>> If that's the case, what would be wrong with cutting the eight-foot rod into
>>> two 48-inch rods and driving them 96 inches apart?
>>>
>>> The point of eight- or ten-foot ground rods is to get eight or ten feet of
>>> contact area, not necessarily to get eight or ten feet deep, yes?
>>>
>>> Just curious on all this.
>>>
>>> 73, kelly
>>> ve4xt
>
>
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