Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-db04.r1000.mx.aol.com (Internet Inbound) with ESMTP id AB7A238000083; Wed, 12 Oct 2011 04:09:11 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RDtr4-0000Co-3e for rs_out_1@blacksheep.org; Wed, 12 Oct 2011 09:07:58 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RDtr3-0000Ce-FN for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2011 09:07:57 +0100 Received: from filter02.i-online.fr ([195.200.78.9]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RDtr2-0003sw-8H for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2011 09:07:57 +0100 Received: from smtp.qtxt.dns-iol.com ([195.200.78.13]) by filter02.i-online.fr (IceWarp 10.2.2) with ESMTP (SSL) id VST61232 for ; Wed, 12 Oct 2011 10:07:32 +0200 Received: (qmail 27394 invoked by uid 507); 12 Oct 2011 10:07:47 +0200 Received: from unknown (HELO ?192.168.1.101?) (john.rabson@numeo.fr@217.67.155.178) by smtp.qtxt.dns-iol.com with SMTP; 12 Oct 2011 10:07:47 +0200 Mime-Version: 1.0 (Apple Message framework v1084) From: John Rabson In-Reply-To: Date: Wed, 12 Oct 2011 10:07:48 +0200 Message-Id: References: To: rsgb_lf_group@blacksheep.org X-Mailer: Apple Mail (2.1084) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Content-Type: text/plain; charset=us-ascii Subject: Re: LF: noise on VK and earth dipole tests Content-Transfer-Encoding: quoted-printable X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:471744512:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40584e954b270cb1 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none hi Dimitrios, On 11 Oct 2011, at 23:37CEST, Dimitrios Tsifakis wrote: > ... > By the way, has anyone in the group experimented with transmitting > into the ground with earth probes? It seems to be working reasonably > well here, in fact I have been thinking that it's comparable to my > very limited inverted-L LF antenna... >=20 > http://people.physics.anu.edu.au/~dxt103/136/earth/ >=20 Amongst other things, it depends on the geology. G3XBM has managed 5.6 = km with 5 W RF at very low frequency. On 87 kHz with 4W SSB (cave = radio) in limestone, the best I know of is 1.6 km two way and 2.5 km one = way in the French alps. It is always worth trying. John F5VLF