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Re: Topband: Ground Conductivity

To: "Chortek, Robert L." <Robert.Chortek@berliner.com>
Subject: Re: Topband: Ground Conductivity
From: Dave Cuthbert <telegrapher9@gmail.com>
Date: Mon, 23 Mar 2020 13:35:33 -1000
List-post: <mailto:topband@contesting.com>
Robert,

an EZNEC model of your vertical as described in your QRZ bio shows your
measured 29.7 ohm input resistance when ground conductivity is set to *0.008
S/m*. EZNEC calls this (0.0075S/12) ground *flat, marshy, densely wooded*.
Using 0.005/13 ground EZNEC reports 35 ohms.

     Dave KH6AQ

On Mon, Mar 23, 2020 at 1:21 PM Dave Cuthbert <telegrapher9@gmail.com>
wrote:

> AA6VB, QTH San Jose, California looks like *8 mS/m*
>
> FCC ground conductivity map
> https://www.fcc.gov/media/radio/m3-ground-conductivity-map
>
> A more detailed map
> https://www.americanradiohistory.com/FCC_Ground_Conductivity_Maps.htm
>
> 1 skin depth t 1.8 MHz in 8 mS/m soil is ~4 meters
>
>     Dave KH6AQ
>
> On Mon, Mar 23, 2020 at 12:02 PM Chortek, Robert L. <
> Robert.Chortek@berliner.com> wrote:
>
>> A quick question for the collective wisdom on this esteemed reflector:
>>
>> How would one categorize the quality of ground consisting of grass. For
>> example, if you live next to a large (many acres) open space made entirely
>> of well watered grass, would that qualify as “average ground“, “above
>> average ground” or something else?
>>
>> Haven’t been able to find the answer anywhere.
>>
>> Thanks for your input, as always!
>>
>> 73 es DX,
>>
>> Bob/AA6VB
>> Robert L. Chortek
>> _________________
>> Searchable Archives: http://www.contesting.com/_topband - Topband
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>>
>
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