Agreed, but for most people, connect/disconnect is by far the easiest way
to go if it's not overly inconvenient. For a contest multi-station,
absolutely stay connected because of the level of hassle otherwise. But for
joe semi-average ham, a clean break is simple and works 100% of the time
(assuming you do it each time, which I do).
Keeps lightning out of the house/station instead of trying to do something
with it when it arrives.
Michael Goins, K5WMG
Professor, Writing
University of Texas at San Antonio
*
*
On Fri, Nov 16, 2012 at 11:17 AM, Jim Lux <jimlux@earthlink.net> wrote:
> On 11/16/12 7:46 AM, K1TTT wrote:
>
>> My program doesn't do strap, so instead of 2" strap that the OP has, I
>> substituted 1" wire which gives a slightly smaller surface area... the OP
>> said he was going have 700' of buried stuff so that is what I used... of
>> course you can't bury in rock, but I can simulate it as a worst case, the
>> 1'
>> of topsoil on top shows there isn't much difference.
>>
>>
> From a transient behavior standpoint, I would imagine that the wire could
> be insulated it and would work about the same. 700 feet x 1/3 foot is
> around 230 square feet of surface area, or 22 square meters..
>
> if it's separated by 1mm from the "earth", that's a capacitance of
> 8.85E-12* 22/1E-3 F or about .2 uF...
>
> At a nominal 1 MHz (for lightning), that's an impedance of a bit less than
> an ohm...
>
>
> and, because I'm a fan of Ufer grounds.. a 3x3x3 foot cube of concrete in
> soil with the top surface exposed has a surface area of 45 square feet, so
> its capacitive impedance is about 4 ohms.. a 5x5x5 cube is about 2 ohms..
> so don't worry about the vapor barrier between concrete and soil. The
> concrete has lower inductance than the wire radials, too..
>
>
>
>
>
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