Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 25A92380000BC; Mon, 8 Aug 2011 15:02:00 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QqV4i-0002JV-GR for rs_out_1@blacksheep.org; Mon, 08 Aug 2011 20:01:20 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QqV4h-0002JM-VO for rsgb_lf_group@blacksheep.org; Mon, 08 Aug 2011 20:01:19 +0100 Received: from mail-pz0-f42.google.com ([209.85.210.42]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QqV4e-0004wK-Bi for rsgb_lf_group@blacksheep.org; Mon, 08 Aug 2011 20:01:19 +0100 Received: by pzk37 with SMTP id 37so8736467pzk.1 for ; Mon, 08 Aug 2011 12:01:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=uu/SAMzPNRZFhothtoRVMo7k2uSpKKUszZUW3e+MT3I=; b=yFtacSRO5yNwjaNzDRH58wOoaPLEXuX7u9DfjJXqS9hLB7Ucybd/+ubdrnLi19SKSN +lM1NZNY/HJO6sUkmn/UMF8WBE3mAo6Z/EfxqUvOqG5N/ZVM5E1RUjbiY6BPFkr3y57V SUS25CSvRtHemHwcHUdO0U2XF5n4hL+EFdN1s= MIME-Version: 1.0 Received: by 10.142.225.11 with SMTP id x11mr5961462wfg.221.1312830068288; Mon, 08 Aug 2011 12:01:08 -0700 (PDT) Received: by 10.142.178.4 with HTTP; Mon, 8 Aug 2011 12:01:08 -0700 (PDT) In-Reply-To: <002901cc55f2$d098c060$0401a8c0@xphd97xgq27nyf> References: <002901cc55f2$d098c060$0401a8c0@xphd97xgq27nyf> Date: Mon, 8 Aug 2011 20:01:08 +0100 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Re: 1.095kHz earth mode test at 6km Content-Type: multipart/alternative; boundary=000e0cd29b9edeebf304aa0311f9 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE 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: 0:2:457703200:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d025.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60ce4e4032a87d11 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --000e0cd29b9edeebf304aa0311f9 Content-Type: text/plain; charset=ISO-8859-1 Thanks Mal. Encouraging as ever. On 8 August 2011 18:44, mal hamilton wrote: > ** > To day my lawn is covered with MOLE MOUNDS of soil. As far as I can see all > you are doing is driving the MOLE population up NORTH > QRP es Underground earth mode induction seems to achieve little for big > effort !! The local Music Rave can be heard 19 miles away > in Audio mode using loudspearkers, a 2 Kw amplifier and an Appliance > Operator !!! > > G3KEV > > > > > ----- Original Message ----- > *From:* Roger Lapthorn > *To:* rsgb_lf_group@blacksheep.org > *Sent:* Monday, August 08, 2011 2:45 PM > *Subject:* LF: 1.095kHz earth mode test at 6km > > Today I repeated the earth mode (through the ground) "long carrier" test of > 17.7.11 this time at 1.095kHz rather than 8.760kHz. The same test location > was used in the fens not far from the River Cam. This is now a very long way > from home! As before, I got my XYL to cut the carrier for periods of 1 or 2 > minutes to positively identify my signal. I need to automate this so she can > continue to do the gardening.... > > 4 different receiving antenna arrangements were tested, using my low > impedance MPF102 tuned preamp into the PC: > > (a) an earth electrode pair parallel with the road, > (b) an earth electrode pair diagonally across the road, > (c) a single turn loop in the road, and > (d) a 30t 80cm diameter loop at the edge of the road. > > Best results were with (a) and (d). With (b) there was no detectable. > > At 1.095kHz the signal was again around 10dB S/N in 11mHz bandwidth on (a) > and (d) and marginally weaker on (c). This is a similar result to 8.76kHz > although I was expecting the signal to be stronger at this lower frequency. > I'm now tempted to do an earth mode test at a *higher* frequency, possibly > 17.52kHz which I can still see with Spectran and Spectrum Laboratory and I > can derive with my 4060 divider circuit. Using earth mode I believe I'll > still be legal as very little radiated signal can be present. > > The image attached shows the signal with the RX earth electrodes parallel > to the road, i.e. set-up (a), at a distance of 6km from the home QTH where > the TX was running 5W into 20m spaced earth electrodes. > > 73s > Roger G3XBM > > -- > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > http://www.youtube.com/user/g3xbm > https://sites.google.com/site/sub9khz/ > > -- http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm https://sites.google.com/site/sub9khz/ --000e0cd29b9edeebf304aa0311f9 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks Mal. Encouraging as ever.

On 8 Aug= ust 2011 18:44, mal hamilton <g3kevmal@talktalk.net> wrote:
To day my lawn is covered with MOLE MOUNDS of soi= l. As far=20 as I can see all you are doing is driving the MOLE population up=20 NORTH
QRP es Underground earth mode induction seems to = achieve=20 little for big effort !! The local Music Rave can be heard 19 miles=20 away
in Audio mode using loudspearkers, a 2 Kw amplifi= er and=20 an=A0 Appliance Operator !!!
=A0
G3KEV
=A0
=A0
=A0
----- Original Message -----
Sent: Monday, August 08, 2011 2:45= =20 PM
Subject: LF: 1.095kHz earth mode te= st at=20 6km

Today I repeated the earth mode (through the ground) "= ;long=20 carrier" test of 17.7.11 this time at 1.095kHz rather than 8.760kHz.= The same=20 test location was used in the fens not far from the River Cam. This is no= w a=20 very long way from home! As before, I got my XYL to cut the carrier for= =20 periods of 1 or 2 minutes to positively identify my signal. I need to aut= omate=20 this so she can continue to do the gardening....

4 different recei= ving=20 antenna arrangements were tested, using my low impedance MPF102 tuned pre= amp=20 into the PC:

(a) an earth electrode pair parallel with= the=20 road,
(b) an earth electrode pair diagonally across the road,
(c)= a=20 single turn loop in the road, and
(d) a 30t 80cm diameter loop at the= edge=20 of the road.=A0

Best results were with (a) and (d). With (b= )=20 there was no detectable.=A0

At 1.095kHz the signal was again arou= nd=20 10dB S/N in 11mHz bandwidth on (a) and (d) and marginally weaker on (c). = This=20 is a similar result to 8.76kHz although I was expecting the signal to be= =20 stronger at this lower frequency.=A0 I'm now tempted to do an earth m= ode=20 test at a higher frequency, possibly 17.52kHz which I can still se= e=20 with Spectran and Spectrum Laboratory and I can derive with my 4060 divid= er=20 circuit.=A0Using earth mode I believe I'll still be legal as very lit= tle=20 radiated signal can be present.

The image attached shows the sign= al=20 with the RX earth electrodes parallel to the road, i.e. set-up (a), at a= =20 distance of 6km from the home QTH where the TX was running 5W into 20m sp= aced=20 earth electrodes.

73s
Roger G3XBM

--
http://g3xbm-qrp.blogspot.com= /
http://www.g3= xbm.co.uk
http://www.= youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/

<= /blockquote>



--
http://g3xbm-qrp.blogspot.com/http://www.g3xbm.co.u= k
http://www.= youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/

--000e0cd29b9edeebf304aa0311f9--