Some years ago Polyphaser was working to develop a "dynamic ground impedance
tester". He tried using a large ball several feet in diameter as a
reference. It worked somewhat but the problem was too much leakage of charge
and readings were unreliable.
73
Gary K4FMX
> -----Original Message-----
> From: towertalk-bounces@contesting.com [mailto:towertalk-
> bounces@contesting.com] On Behalf Of Pete Smith
> Sent: Monday, August 14, 2006 10:44 AM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Ground Resistance
>
> Rather than looking just at resistance, why not try to more fully
> characterize ground parameters? I fuzzily recall that a VE2 working at
> the Canadian government's antenna lab suggested years ago that you erect a
> very low dipole for the frequency of interest and then tweak ground
> parameters in a NEC-2 model until the resonant frequency and feedpoint
> impedance closely match the observed values. Is there something wrong
> with that approach?
>
> 73, Pete N4ZR
>
> At 12:19 AM 8/14/2006, Jim Lux wrote:
> >At 03:25 PM 8/8/2006, David Robbins K1TTT wrote:
> >>Way, yes... simple, not really. There are meters made for measuring
> ground
> >>system resistance, but they rely on either a very good reference ground
> >>nearby, or a couple of rods spaced the right distances apart to act as a
> >>reference. Its been some years since I used one so I forget the exact
> >>process, but its spelled out in detail in the manuals. The one I used
> last
> >>was made by Biddle if I remember correctly. Check with a local
> electrician
> >>or electric company crew, they may have one and could make the
> measurements
> >>for you. Or the meters can be rented from electronic rental places if
> you
> >>want to do it yourself.
> >
> >And, of course, such a meter would measure at some frequency OTHER than
> the
> >HF frequency you're actually interested in.
> >
> >I suppose one could do something like measure the received signal
> strength
> >from a fixed beacon, and keep adding radials until the difference is
> "small
> >enough".. Lots of traps here for the unwary, the vagaries of propagation
> >being but one.
> >Jim
> >
> >
> >
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