Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dg01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2074C380000E4; Wed, 12 Oct 2011 04:29:19 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RDuAc-0000XN-MW for rs_out_1@blacksheep.org; Wed, 12 Oct 2011 09:28:10 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RDuAc-0000XE-AW for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2011 09:28:10 +0100 Received: from out1.ip09ir2.opaltelecom.net ([62.24.128.245]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RDuAa-000472-7n for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2011 09:28:10 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AkoCAB5PlU5cHYnV/2dsb2JhbABDFokaj1EBCUOOW4EGgU4FAQEEAQgBAQNJAiYGAQEDBQIBAxEEAQEKJRQBBBoGFggGEwoBAgIBAYdtAga4LYdYBIdPnXo X-IronPort-AV: E=Sophos;i="4.69,333,1315177200"; d="scan'208";a="493283578" Received: from host-92-29-137-213.as13285.net (HELO xphd97xgq27nyf) ([92.29.137.213]) by out1.ip09ir2.opaltelecom.net with SMTP; 12 Oct 2011 09:28:02 +0100 Message-ID: <002501cc88b8$d6fda990$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: Date: Wed, 12 Oct 2011 08:27:54 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: noise on VK and earth dipole tests Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit 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: 0:2:492830720:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d41094e954fdf5577 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Earth probes not suitable for DX but good for cave exploration, looking for Bats and the Loch Ness Monster g3kev ----- Original Message ----- From: "John Rabson" To: Sent: Wednesday, October 12, 2011 8:07 AM Subject: Re: LF: noise on VK and earth dipole tests 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... > > http://people.physics.anu.edu.au/~dxt103/136/earth/ > 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