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LF: Re: Earthing systems

To: [email protected]
Subject: LF: Re: Earthing systems
From: "captbrian" <[email protected]>
Date: Sat, 26 Jun 2004 09:07:05 +0100
References: <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
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 <[email protected]>
To: LF-Group <[email protected]>
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
[email protected]






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