Message-ID: <004101c345ef$52d38500$0c2465d5@oemcomputer>
From: "Johan Bodin" <sm6lkm.jbeab@swipnet.se>
To: rsgb_lf_group@blacksheep.org
References: <001b01c345d6$cf184ce0$e3c428c3@captbrian>
Date: Wed, 9 Jul 2003 09:53:55 +0200
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Subject: LF: Re: earth losses
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Bryan,


>  Of the earth return loss resistance, how much of the resistance is the
> actual earth rod(s)-to-soil contact and how much is the earth path ?

that is a very interesting question but it is difficult, if not impossible, to
give an exact answer. However, in a typical amateur antenna, the earth
path is responsible for a considerable part of the total resistance.

I believe in G3AQC's "footprint theory" - the more ground area covered by
the top loading wire(s), the better. More lawn in parallel, so to speak :-)


> With an  inverted L antenna ,  is not a counterpoise of the same length as
> the horizontal section and directly underneath but a few feet off the ground
> a good way of avoiding the earth rod to soil contact losses ??

I have tried such a ground wire with an 15m up / 85m out inverted L but there
was no detectable difference. Feedpoint resistance was around 35 ohms
in both cases (including coil loss etc). Probably because the wire "catched"
only a fraction of the total E field. I did not try using the (slightly) elevated ground
wire as the only ground ("floating antenna") because I ran out of loading inductance...

73
Johan SM6LKM