Return-Path: Received: from mtain-mb04.r1000.mx.aol.com (mtain-mb04.r1000.mx.aol.com [172.29.96.24]) by air-mc08.mail.aol.com (v129.4) with ESMTP id MAILINMC082-a98c4c6ad6d4241; Tue, 17 Aug 2010 14:37:08 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mb04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 65C703800652B; Tue, 17 Aug 2010 14:34:42 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OlQyD-0007q8-N3 for rs_out_1@blacksheep.org; Tue, 17 Aug 2010 19:33:09 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OlQyD-0007pz-3M for rsgb_lf_group@blacksheep.org; Tue, 17 Aug 2010 19:33:09 +0100 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OlQyB-0000Ee-Ea for rsgb_lf_group@blacksheep.org; Tue, 17 Aug 2010 19:33:08 +0100 Received: by bwz16 with SMTP id 16so3022320bwz.16 for ; Tue, 17 Aug 2010 11:33:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=NZnadWPd3K0Z5EGgm+xWox/sMlgKc7iOrpaagv07mjc=; b=bwwoj0alWDUxiGMrYVuTwM7Frcky++ygr9V4LXMyEjl7LyraMl1xMKPuZSXyrtSe/F XTj8jTV3fc9H+UivKJz7RmVYORAxzTflbwcyJNUa76K8YbEuIcbTFS2mrW2CqjQGyxQj j50XK73FG6YpTSP7RHvAU4iITx8j+jzE82Kwc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=FZA5UxSjtP4beZxC92gakRgEwK6H/fxgBzHr680EH4RwhvaPdbLmp+F9oAGW/6MvpZ mLciSFvm/loZH+uwY7v5/82DoyiGLrN42y8q62LH7fBjMgW25pJwhP1rD0NSGvbgFOy0 K2krqtaiFsy7Jo0Ca6VvKEXvk8GxrAMtTeYQA= MIME-Version: 1.0 Received: by 10.204.34.133 with SMTP id l5mr4654416bkd.180.1282069986078; Tue, 17 Aug 2010 11:33:06 -0700 (PDT) Received: by 10.204.202.71 with HTTP; Tue, 17 Aug 2010 11:33:06 -0700 (PDT) In-Reply-To: <4C6AA6BB.8020004@o2.ie> References: <4C694CC6.3010609@o2.ie> <4C69AAB7.5070006@iup.uni-heidelberg.de> <4C6AA6BB.8020004@o2.ie> Date: Tue, 17 Aug 2010 19:33:06 +0100 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Earth electrode antenna tests Content-Type: multipart/alternative; boundary=0003255575fa18f101048e092e62 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=HTML_FONTCOLOR_UNSAFE, 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-AUTHENTICATION: mail_rly_antispam_dkim-d258.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60184c6ad6425434 X-AOL-IP: 193.82.116.20 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --0003255575fa18f101048e092e62 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Your findings also tie up with mine Tony. On 136kHz the 20m spaced TX earth electrode behaves as a loop in terms of far field directionality with nulls orthogonal to the line of the electrod= es and strongest signals end on. This also ties up with my WSPR reports on 500kHz which came from N.Holland, Tring and Bristol i.e. in the line of th= e electrodes with no reports orthogonal to the electrode alignment. On 0.838kHz the best orientation when picking up pure induction signals (u= p to around 0.5km) was orthogonal to the electrodes. When receiving "utiliti= es assisted" conducted signals 5.6km away the orientation did not matter, whi= ch is what one would expect. There is no doubt in my mind that *this sort of "antenna" behaves like a loop* on 136 and 500kHz. By the way, good luck Stefan with the earth electrode DX tests. 73s Roger G3XBM On 17 August 2010 16:11, Tony wrote: > Hi Stefan > > I tried the antennae this afternoon on 23 KHz and the E/W wire is 12dB= up > on the N/S wire. > I have no idea what I was receiving as I was using a FRG-7700 which only > displays to the nearest KHz. > When I disconnected the far end from the earth stake the signal dropped= by > 18dB, the receiver is at the eastern end of the E/W wire and the norther= n > end of the N/S wire. > > I will try sub 10 KHz when I sort out where my local QRM is coming from. > > Tony, EI8JK. > > > > On 16/08/2010 22:16, Stefan Sch=E4fer wrote: > >> Hello Tony, >> >> Thanks for that interesting work! >> Could you extend the measurements to the VLF band? It would be interest= ing >> what the levels and directivity would be there. >> >> 73 and pse a sked for your upcoming LF stn! :-) >> >> Stefan/DK7FC >> >> Am 16.08.2010 16:35, schrieb Tony: >> >>> Yesterday I spent some time playing with different antennae. >>> I started by laying out another wire 52m long orientated roughly >>> north/south and then I shortened my original wire also to be 52m and= this >>> one is east/west, both terminated with an earth rod. >>> Results were not as expected however as although the two earth electro= de >>> antennae show most definite directivity they were the wrong direction. >>> >>> I monitored BBC R. Bristol on 1548 KHz which is about 500 Km due east= of >>> me and on the inverted L (tuned VSWR 1.6:1) I could just detect a carr= ier >>> heterodyne, on the N/S earth electrode antenna it was S1 but on the E/= W >>> earth electrode antenna it was S3. >>> RNE5 on 531 KHz about 960 Km due south of me was S3 on the E/W and S8= on >>> the N/S >>> >>> HGA22 (135 KHz) to my east was S4 on the E/W and S1 on N/S >>> >>> Readings were taken about 12:00 utc so most definitely ground wave. >>> >>> I was expecting the directivity to be broadside on the earth electrode >>> antennae, but they seem to behave like a Beverage in that respect, but >>> something that I think I will investigate further, maybe see if there= is any >>> difference if I terminate them with a resistor. >>> I'm sure Mal is correct though that they would be useless to TX throug= h >>> but for RX they seem to have possibilities especially after dark as th= ey are >>> a lot quieter. >>> >>> All good fun. >>> 73, Tony, EI8JK. >>> >> >> >> >> > > --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --0003255575fa18f101048e092e62 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Your findings also tie up with mine Tony.

On 136kHz the 20m spaced= TX earth electrode behaves as a loop in terms of far field directionality= with nulls orthogonal to the line of the electrodes and strongest signals= end on. This also ties up with my WSPR reports on 500kHz which came from= N.Holland, Tring and Bristol i.e. in the line of the electrodes with no= reports orthogonal to the electrode alignment.

On 0.838kHz the best orientation when picking up pure induction signal= s (up to around 0.5km) was orthogonal to the electrodes. When receiving &q= uot;utilities assisted" conducted signals 5.6km away the orientation= did not matter, which is what one would expect.

There is no doubt in my mind that this sort of "antenna&quo= t; behaves like a loop on 136 and 500kHz.

By the way, good= luck Stefan with the earth electrode DX tests.

73s
Roger G3XBM<= br>
=A0

On 17 August 2010 16:11, Tony <ei8jk@o2.ie> wrote:
=A0Hi Stefan

I tried the antennae this afternoon on 23 KHz and the E/W wire is 12dB up= on the N/S wire.
I have no idea what I was receiving as I was using a FRG-7700 which only= displays to the nearest KHz.
When I disconnected the far end from the earth stake the signal dropped by= 18dB, the receiver is at the eastern end of the E/W wire and the northern= end of the N/S wire.

I will try sub 10 KHz when I sort out where my local QRM is coming from.
Tony, EI8JK.



On 16/08/2010 22:16, Stefan Sch=E4fer wrote:
Hello Tony,

Thanks for that interesting work!
Could you extend the measurements to the VLF band? It would be interesting= what the levels and directivity would be there.

73 and pse a sked for your upcoming LF stn! :-)

Stefan/DK7FC

Am 16.08.2010 16:35, schrieb Tony:
=A0Yesterday I spent some time playing with different antennae.
I started by laying out another wire 52m long orientated roughly north/sou= th and then I shortened my original wire also to be 52m and this one is ea= st/west, both terminated with an earth rod.
Results were not as expected however as although the two earth electrode= antennae show most definite directivity they were the wrong direction.
I monitored BBC R. Bristol on 1548 KHz which is about 500 Km due east of= me and on the inverted L (tuned VSWR 1.6:1) I could just detect a carrier= heterodyne, on the N/S earth electrode antenna it was S1 but on the E/W= earth electrode antenna it was S3.
RNE5 on 531 KHz about 960 Km due south of me was S3 on the E/W and S8 on= the N/S

HGA22 (135 KHz) to my east was S4 on the E/W and S1 on N/S

Readings were taken about 12:00 utc so most definitely ground wave.

I was expecting the directivity to be broadside on the earth electrode ant= ennae, but they seem to behave like a Beverage in that respect, but someth= ing that I think I will investigate further, maybe see if there is any dif= ference if I terminate them with a resistor.
I'm sure Mal is correct though that they would be useless to TX throug= h but for RX they seem to have possibilities especially after dark as they= are a lot quieter.

All good fun.
73, Tony, EI8JK.








--
http://g3xbm-qrp.blogsp= ot.com/
http:/= /www.g3xbm.co.uk
http://www= .youtube.com/user/g3xbm
G3XBM=A0=A0 GQRP 1678=A0=A0=A0 ISWL G11088<= br> --0003255575fa18f101048e092e62--