Envelope-to: dave@picks.force9.co.uk
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Date: Mon, 01 Aug 2005 13:09:03 +0000
From: Johan Bodin <jbodin@tele2.se>
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To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: Suitable ground?
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Yes, I have been using the 150mm (6") pipe in our well with quite good
results. The pipe is 12m long and goes about 11 m (36ft) through soil
and about 1m into the granite rock below (total hole depth is 111m).

At resonance, my antenna had a feedpoint resistance of 35 ohms.
The loading coil loss was around 8 ohms, including the variometer,
leaving a loss resistance of about 27 ohms for ground connection +
"environmental loss". The TX was connected to the pipe ground via
25m 2.5mm^2 wire laying on the ground. I made an interesting observation
when connecting the mains protective ground in parallel with the
"pipe ground" - the feedpoint resistance increased to 50-60 ohms!...

The antenna was an 85 meter long inverted L at an average height of 14m.

73
Johan SM6LKM


J. B. Weazle McCreath wrote:
> [...] However, about 150 feet from my house is a water well in the
 > form of an 8 inch diameter steel pipe that goes down 275 feet!
 > Has anyone on the list had any experience using such as a ground
 > for a Marconi antenna? [...]


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