Hi, Rik.
On Tue, 14 May 2002, Rik Strobbe wrote:
>If Lcp=0 this means that ground wire only touch to the ground in infinity
>small point. So R should be infinity large. If there is no conterpoint
>Lcp is a ground rod length.
I agree about Lcp is really 0.
But if I take Lcp = 0.2m (short ground rod only), Lant= 30m , C = 150pF (Xc
= 7800 Ohm) and a = 0.01 then R = (Lant/Lcp)*a*Xc = 11700 Ohm. I believe
that this value is far too high, a more realistic value would be a few
hundred Ohm.
When I derive the formula I assumed wires capacitance 5 pF/meter
If wire is VERY short (0.2 meters) it's not true. For such a short
wire there is about 20 pF/meter. If do some corrections resistance for
ground rode of 0.2 meter is about 3000 Ohm, not 11700 Ohm.
Are You sure real resistance is few hundred Ohm WHEN THERE IS NO LONG
WIRE to connect TX to such a short ground rod? Does You do such
experiment?
73 de RA9MB/Alex
http://www.qsl.net/ra9mb
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