[600MRG] ground

[Larry]

Ed,

It is a desert. Central WA really is a desert. If it were not for the 
Columbia River irrigation project there would be no agriculture other 
than dry land wheat in this area. We average 7 inches yearly 
precipitation just like I had down in central AZ.

But, we do have the irrigation and lots of water. During the summer I 
run sprinklers on the antenna patch. If I didn't keep grass growing 
there, the wind erosion would have all of my buried radials running 
across the top of exposed rocks in a year or less.

Virtually all moisture percolates down or evaporates in about a week 
during the summer unless I irrigate. When I irrigate I can run 
sprinklers for 48 hours and put down the equivalent of 2 inches of rain 
under the vertical. No change in feed point impedance. Ever.

73, Larry - W7IUV / WH2XGP

On 07-Feb-15 8:42 AM, Edward R Cole wrote:
> Larry,
>
> What you describe sounds like definition of a desert.  Only thing in
> your soil that will hold moisture might be the cliche.  I suspect your
> soil never gets wet enough to cause a significant change in
> conductivity.  Also helps is your ground radial system.
>
> I believe I once visited your place (probably on a trip to attend the
> conference at Moses Lake).  It looks a lot like desert unless you
> irrigate it.
>
> 73, Ed - KL7UW
>
> At 06:45 AM 2/7/2015, Larry wrote:
>> OK, what am I missing here?
>>
>> My 630 meter vertical antenna system shows no measurable difference in
>> feed point impedance between bone dry dirt and soggy wet dirt.
>>
>> For that matter neither does my 160 meter vertical.
>>
>> My dirt is composed of volcanic ash, sand, and rock. The so called top
>> soil averages 30 inches deep over cliche and basalt. It is so bad
>> during summer that electric fences are no longer effective unless the
>> pasture is irrigated!
>>
>> The 160 vertical is over a radial system composed of 82x 100 foot
>> symmetrically positioned buried wires in a clear 1.5 acre area. I. E.
>> no trees, no towers, no houses, etc.
>>
>> The 630 meter vertical is over 16x 25 foot buried wires but the area
>> is more cluttered with nearby conductive objects like metal buildings
>> and towers.
>>
>> So can anybody tell me why I NEVER see variations in feedpoint
>> impedance due to ground changes on ANY vertical antenna system I have
>> used?
>>
>> 73,
>>
>> Larry - W7IUV / WH2XGP
>>
>>
>>
>>
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>
> 73, Ed - KL7UW
> http://www.kl7uw.com
>      "Kits made by KL7UW"
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>
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