Message-ID: <000f01c45b54$92822640$31540150@captbrian>
From: "captbrian" <captbrian@ukonline.co.uk>
To: rsgb_lf_group@blacksheep.org
References: <000901c45b0a$de3c2260$6507a8c0@Main>
Date: Sat, 26 Jun 2004 09:07:05 +0100
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Subject: LF: Re: Earthing systems
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You've changed his uF to nF.

Are the radials insulated ?

Are the radials grounded at the 'inboard' end?

If insulated and not inboard grounded then: IF a 45' buried wire is series
resonant with .047uF at 136 (which I doubt) then he has two quarter waves in
series fed at the centre and capacity coupled to earth at one end.[Ugh!] The
outer of the feeder coax not at earth potential ?

I wish someone cleverer than I would comment on the capacitance to earth of
buried wires (such capacitance is in parallel with his .047 and the effect
of the earth on buried  wires' inductance.

I wish Ed would tell us how he determined the 'resonance' of his radials

Like you I applaud his experimental energy but suspect the results may be
the esult of misleading measurements.

Bryan G3GVB


----- Original Message -----
From: Alan Melia <Alan.Melia@btinternet.com>
To: LF-Group <rsgb_lf_group@blacksheep.org>
Sent: Saturday, June 26, 2004 12:19 AM
Subject: LF: Earthing systems


> Hi all, I offer  below, culled from the LWCA message board, a description
of
> an "improved" eathing system for LF.  To me this does not make sense, but
> maybe I am missing something...any thoughts anywhere?? I can see that the
> small inductance of the very short (45feet..14m) "radial" could "impede"
the
> passage of current collected at the remote ground spike, but I do not
really
> see what is happening. We may have to wait for the article to hear the
full
> measurement detail. I am worried that he has measured the soil
conductivity
> at 60Hz ....this has little relation to ground loss effects at 136 to
> 180kHz....though maybe if it drops at 60Hz it is somewhat better at 136 ??
> ---------------------------------
> Hi Eric,
> I'm working on an article for an upcoming LOWDOWN on the system, but
> briefly, it goes like this; at the far end of EACH radial is a 4 or 8 ft
> ground rod (most are 8') with a series capacitor between the radial end
and
> the ground rod. This capacitor is VERY important as it cancels out the XL
of
> the buried radial and really maximizes the available current in said
> radial.Here, on a 45' radial(the longest) it requires a 0.047uF value. On
> the 20 footers,(the shortest) it runs about 0.15 uF. The bad news is I
have
> 134 radials!! Lots of expense and lots of exercise.(I LOVE to experiment)
> Hope this info helps you. 73, Ed G.
> -------------------------------
>
> 0.047nF resonates with 29uH at 136 and about 16uH at 180Khz....my belief
is
> that a short wire (less than a 1/4wave is capacitive not inductive at LF,
> though a straight piece of insulated wire measured away from resonance
will
> have some inductance.
>
> My though is if this really does work it could be helpful tho those with
> short back gradens, but I worry that Ed may not have measured the aerial
> system properly and could maybe be fooling himself (I've done it myself
> before I started to use an RF bridge)
>
> I am not trying to nit-pick on Ed's energetic works, but would like to ask
> him the right questions (maybe suggest some different measurements) so
that
> we could, maybe, understand what is happening.
>
> Cheers de Alan G3NYK
> alan.melia@btintermnet.com
>
>
>
>