Return-Path: Received: from mtain-da04.r1000.mx.aol.com (mtain-da04.r1000.mx.aol.com [172.29.64.76]) by air-me05.mail.aol.com (v129.4) with ESMTP id MAILINME054-8bb34c21ef0f211; Wed, 23 Jun 2010 07:25:03 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-da04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2D960380000BD; Wed, 23 Jun 2010 07:24:57 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ORO18-0008Vi-Ug for rs_out_1@blacksheep.org; Wed, 23 Jun 2010 12:21:18 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ORO18-0008VY-CC for rsgb_lf_group@blacksheep.org; Wed, 23 Jun 2010 12:21:18 +0100 Received: from blu0-omc1-s26.blu0.hotmail.com ([65.55.116.37]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1ORO11-0006H6-Sz for rsgb_lf_group@blacksheep.org; Wed, 23 Jun 2010 12:21:18 +0100 Received: from BLU146-W18 ([65.55.116.7]) by blu0-omc1-s26.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4675); Wed, 23 Jun 2010 04:20:56 -0700 Message-ID: X-Originating-IP: [67.60.204.92] From: Laurence KL7UK To: Date: Wed, 23 Jun 2010 03:20:56 -0800 Importance: Normal In-Reply-To: References: ,,, MIME-Version: 1.0 X-OriginalArrivalTime: 23 Jun 2010 11:20:56.0750 (UTC) FILETIME=[266A0CE0:01CB12C6] X-Spam-Score: 0.7 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,SUBJ_HAS_SPACES=0.651 Content-Type: multipart/alternative; boundary="_a1b6abea-f765-4976-bc20-19d451267ba0_" Subject: RE: LF: RE: VLF QRP Earth mode: 5.1km DX tonight but no such thing as a free lunch X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.5 required=5.0 tests=FORGED_HOTMAIL_RCVD,HTML_20_30, HTML_FONTCOLOR_BLUE,HTML_MESSAGE,SUBJ_HAS_SPACES 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-sid: 3039ac1d404c4c21ef090193 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --_a1b6abea-f765-4976-bc20-19d451267ba0_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Some interesting reading perhaps - In a former life Ive spent hours, some= times days wandering around neighborhoods with my DF set and SG browns tra= cking painful tv/radio interference issues and can vouch for the interacti= on! =20 http://www.netl.doe.gov/technologies/oil-gas/publications/td/FG113004.PDF =20 Laurence =20 Date: Wed, 23 Jun 2010 08:42:56 +0100 From: rogerlapthorn@gmail.com To: rsgb_lf_group@blacksheep.org Subject: Re: LF: RE: VLF QRP Earth mode: 5.1km DX tonight but no such thin= g as a free lunch Rik (et al), One earth rod in the sea at each end and another driven into the chalk roc= k 300m inland at each end and would almost guarantee a QSO on 1kHz across= the channel by earth-mode. Anyone crossing the channel would be able to= detect the signal with a loop in a boat. Two rods in the sea at each end= would not work. Also, you do wonder with the network of gas pipes, water pipes, electricit= y pylons, phone lines etc criss-crossing vast swathes of countryside just= how far "utility assisted" (for the want of a better term) earth mode VLF= comms could travel. From my own QRP tests this week I conclude a LOT furt= her than I'd previously thought possible. Of course no direct physical con= nection is needed, just the ability to induce power into these by placing= wire loops or earth electrode loops nearby.=20 This raises another point. However unintentionally, 136kHz, 500kHz and 1.8= MHz signals must, at times, couple into utilities and be "helped" to radia= te more effectively by the presence of cables and pipes. I am now almost= sure that the same mechanism used to conduct my 838Hz signal a very long= way last night must have helped my 500kHz WSPR signal cross the UK last= weekend: there is a signal flowing in the earth electrode "loop in the= ground" as well as a signal flowing around the streets via copper water= pipes. Whether the mechanism at 500kHz or 137kHz is as a result of a loop= or a very long e-field antenna (the copper pipes in the streets) just be= low the surface of the earth is open to debate. Fascinating. 73s Roger G3XBM On 23 June 2010 08:15, Rik Strobbe wrote: Yet another thought: =20 salt water is a rather good conductor. What about a couple of rods into the sea near Dover and another pair near= Cap Griz Nez ? Distance is 34 km. =20 73, Rik ON7YD =20 Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.or= g] namens Rik Strobbe [Rik.Strobbe@fys.kuleuven.be] Verzonden: woensdag 23 juni 2010 9:00 Aan: rsgb_lf_group@blacksheep.org Onderwerp: LF: RE: VLF QRP Earth mode: 5.1km DX tonight but no such thing= as a free lunch At greater distances (3-5kms) the signal reaches its destination by conduc= tion through the ground aided by pipes in the roads and with inductive cou= pling into the loop at the RX. Roger, =20 very interesting. There are huge gas pipelines running across the country (and even across= Europe). I wonder how far one would get with a ground antenna near one of these.=20 The 2 rods of the ground antenna each at one side of the pipeline would gi= ve optimal coupling. =20 73, Rik ON7YD =20 =20 =20 =20 --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 =20 _________________________________________________________________ Hotmail has tools for the New Busy. Search, chat and e-mail from your inbo= x. http://www.windowslive.com/campaign/thenewbusy?ocid=3DPID28326::T:WLMTAGL:= ON:WL:en-US:WM_HMP:042010_1=3D --_a1b6abea-f765-4976-bc20-19d451267ba0_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Some  interesting reading perhaps - In a former life Ive spent hours,= sometimes days wandering around neighborhoods with my DF set an= d SG browns tracking painful tv/radio interference issues and can vouch fo= r the interaction!
 
http://www.netl.doe.gov/technologies/oil-gas/publications/td/F= G113004.PDF
 
Laurence
 
Date: Wed, 23 Jun 2010 08:42:56 +0100
From: rogerlapthorn@gmail.com
= To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: RE: VLF QRP Earth mod= e: 5.1km DX tonight but no such thing as a free lunch

Rik (et al),<= BR>
One earth rod in the sea at each end and another driven into the ch= alk rock 300m inland at each end and would almost guarantee a QSO= on 1kHz across the channel by earth-mode. Anyone crossing the channel wou= ld be able to detect the signal with a loop in a boat. Two rods in the sea= at each end would not work.

Also, you do wonder with the network= of gas pipes, water pipes, electricity pylons, phone lines etc criss-cros= sing vast swathes of countryside just how far "utility assisted" (for the= want of a better term) earth mode VLF comms could travel. From my own QRP= tests this week I conclude a LOT further than I'd previously thought poss= ible. Of course no direct physical connection is needed, just the ability= to induce power into these by placing wire loops or earth electrode loops= nearby.

This raises another point. However unintentionally, 136kH= z, 500kHz and 1.8MHz signals must, at times, couple into utilities and be= "helped" to radiate more effectively by the presence of cables and pipes.= I am now almost sure that the same mechanism used to conduct my 838Hz sig= nal a very long way last night must have helped my 500kHz WSPR signal cros= s the UK last weekend:  there is a signal flowing in the earth electr= ode "loop in the ground" as well as a signal flowing around the streets vi= a copper water pipes. Whether the mechanism at 500kHz or 137kHz is as a re= sult of a loop or a very long e-field antenna (the copper pipes in the str= eets)  just below the surface of the earth is open to debate.

= Fascinating.

73s
Roger G3XBM



On 23 June 2010 08:15, Rik Strobbe <Rik.Strobbe@fys.= kuleuven.be> wrote:
Yet another thought:
 
salt water is a rather good conductor.
What about a couple of rods into the&nbs= p;sea near Dover and another pair near Cap Griz Nez ?
Distance is 34 km.
 
73, Rik  ON7YD
 <= /DIV>
Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_gro= up@blacksheep.org] namens Rik Strobbe [Rik.Strobbe@fys.kuleuven.be]
Verzonden: woen= sdag 23 juni 2010 9:00
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: LF: RE:= VLF QRP Earth mode: 5.1km DX tonight but no such thing as a free lunch
  1. At greater distances (3-5kms) the signal reac= hes its destination by conduction through the ground aided by pipes in the= roads and with inductive coupling into the loop at the RX.
Roger,<= /DIV>
 
very interesting.
There are huge gas pipelines= running across the country (and even across Europe).
I wonder how far one would get= with a ground antenna near one of these.
The 2 rods of the ground anten= na each at one side of the pipeline would give optimal coupling.
 
73, Rik  ON7YD
 
 
 
 



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http://www.youtube.com/user/g3xbm
G3XBM &n= bsp;  GQRP 1678      ISWL G11088
=
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