Topband: earth tester

[Henk PA5KT]

Another website with a measurement tool:

http://www.technik.dhbw-ravensburg.de/~lau/gc.html

I did not yet try this or N6LF's system.

73 Henk PA5KT

Jorge Diez - CX6VM schreef op 4/22/2015 om 7:34 PM:
> Thanks Jim
>
> I will look at N6LF website, I want to measure my soil conditions
>
> 73,
> Jorge
>
>
> -----Mensaje original-----
> De: Topband [mailto:topband-bounces at contesting.com] En nombre de Jim Brown
> Enviado el: miércoles, 22 de abril de 2015 01:48 p.m.
> Para: topband at contesting.com
> Asunto: Re: Topband: earth tester
>
> What do you want to measure?  These testers, as well as the "fall of
> potential" method, measure the impedance to earth at dc and low audio
> frequencies.
>
> It's important to remember that a connection to earth is for lightning
> protection, and does not make a TX antenna work better.
>
> If you want to measure your soil conditions, N6LF shows a method on his
> website. It uses a driven rod that passes through an opening in a wire
> screen. Z between the rod and the screen is measured using a vector
> impedance analyzer, first before the rod is driven, and again after being
> driven to its full length, and soil parameters are computed from the two
> measurements.  I've thought about doing this, but never got around to it.
> This measurement yields the data on the soil conditions that affect the
> performance of vertical antennas.
>
> 73, Jim K9YC
>
>
>
> On Wed,4/22/2015 6:00 AM, Paul Christensen wrote:
>>> "Do you use a earth tester?  Which brand do you know is very good and
>>> accurate to consider?"
>> Jorge,
>>
>> If you can, try and find a "clamp-on" earth tester rather than the
>> type that relies on the fall-of-potential method with electrodes.
>> There are several good clamp-on units by Megger, Fluke and AEMC. I
>> recently acquired an AEMC model 3711.  It wasn't supplied with a
>> calibration loop, but I found one from Fluke that quickly checks
>> calibration at 100, 50, 12.5, and 0.5 ohms. You'll want that
>> calibration loop to validate the accuracy of the clamp tester,
>> especially if you use an off-brand model from Asia.
>>
>> N4CC and I recently installed a large grounding field, with some
>> ground rods driven down to a depth of 24 ft.  The clamp-on device was
>> useful for quick validation.  Had we used a unit with electrodes, it
>> would have taken us much longer to perform our tests.  By the way, in
>> sandy/clay type soil here in north FL, we found that connecting 8 ft.
>> rods end-to-end to form a 24 ft rod substantially lowered earth
>> resistance by a factor of 10x.
>>
>> Paul, W9AC
>>