Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4CDB038000042; Tue, 8 Jan 2013 16:19:26 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TsgXg-0002Fd-1E for rs_out_1@blacksheep.org; Tue, 08 Jan 2013 21:17:04 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TsgXf-0002FU-GA for rsgb_lf_group@blacksheep.org; Tue, 08 Jan 2013 21:17:03 +0000 Received: from smtpout2.wanadoo.co.uk ([80.12.242.42] helo=smtpout.wanadoo.co.uk) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1TsgXd-0003F6-5K for rsgb_lf_group@blacksheep.org; Tue, 08 Jan 2013 21:17:02 +0000 Received: from AGB ([2.26.16.164]) by mwinf5d22 with ME id lZGg1k00C3YP8Wy03ZGgt2; Tue, 08 Jan 2013 22:16:40 +0100 Message-ID: <1523DBA5E4DD4A8C964ED69185DF5FE5@AGB> From: "Graham" To: References: In-Reply-To: Date: Tue, 8 Jan 2013 21:16:40 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Roger ''directionality along the line of the earth-electrode baseline and a null off the sides'' A terminated travelling wave 'thing'ey' then ! sort of makes sense , the Amps in the top section are maximised by the diffused return path , may be not cancelling ? [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [80.12.242.42 listed in list.dnswl.org] 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 350b42a0642244046701ed1a68bf48aa Subject: Re: LF: Comparing earth-electrode v. Marconi antenna on 472kHz Content-Type: multipart/alternative; boundary="----=_NextPart_000_0121_01CDEDE5.73511600" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30,HTML_MESSAGE, MISSING_OUTLOOK_NAME 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: 3039ac1d60cb50ec8d5e1704 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_0121_01CDEDE5.73511600 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Roger=20 ''directionality along the line of the earth-electrode baseline and a = null off the sides'' A terminated travelling wave 'thing'ey' then ! sort of makes = sense , the Amps in the top section are maximised by the = diffused return path , may be not cancelling ?=20 73 -G.. From: Roger Lapthorn=20 Sent: Tuesday, January 08, 2013 9:06 PM To: rsgb_lf_group@blacksheep.org ; rsgb_lf_group@yahoogroups.co.uk=20 Subject: LF: Comparing earth-electrode v. Marconi antenna on 472kHz This evening I've been noting my WSPR S/N reports from stations across = the country and nearer Europe using my 9m long Marconi antenna (an = average arrangement for a small garden plot like mine - but not the = best) and comparing these with the reports last night when I was using = just the 15m baseline earth-electrode "antenna". I crudely plotted the = "improvement factor" in dB on a polar plot. Each dot represents a = station reporting my signal with the dB improvement over the = earth-electrode antenna plotted on a 0-20dB scale out from the centre. = This is not good science, it is G3XBM science I'm afraid, but it give a = fair idea of the difference and how direction affects this (see attached = rough polar plot). Although in some directions the difference is very little, in other = directions the reports are up to 14dB better on the (omni-directional) = Marconi. My conclusion is that the earth electrode antenna is behaving somewhat = like a loop with some directionality along the line of the = earth-electrode baseline and a null off the sides. With stations = receiving me off the sides there is most improvement with the Marconi, = and less difference with stations end-on who were getting a reasonable = signal with the earth-electrode antenna. CONCLUSION: the simple, stealth, earth-electrode antenna is a VERY = useful antenna on 472kHz as long as one is prepared to accept a 2-14dB = loss compared with a "small garden" Marconi. In all honesty, I am = getting better reports on the Marconi but few new stations are copying = me: most could copy me on the earth electrode antenna.=20 I shall run WSPR overnight to see if any more distant stations copy me, = then probably put away the 472kHz gear and Marconi for a while to find = another interesting challenge - possibly something on 10m or VHF.=20 These last few days have been fun, and that is really what this hobby is = about. 73s Roger G3XBM --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk https://sites.google.com/site/sub9khz/ http://qss2.blogspot.com/ ------=_NextPart_000_0121_01CDEDE5.73511600 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Roger
 
''directionality along the line of the earth-electrode baseline and = a null=20 off the sides''
 
A  terminated  travelling   wave = 'thing'ey'  =20 then !  sort of  makes  sense  , the  = Amps  in=20 the  top  section  are  maximised by  the  = diffused  return  path  , may  be  not =20 cancelling  ?
 
73 -G..
 
 
 

From: Roger Lapthorn
Sent: Tuesday, January 08, 2013 9:06 PM
To: rsgb_lf_group@blacksheep.org= ; rsgb_lf_group@yahoogroups= .co.uk=20
Subject: LF: Comparing earth-electrode v. Marconi antenna on = 472kHz

This evening I've been noting my WSPR S/N reports from stations = across the=20 country and nearer Europe using my 9m long Marconi antenna (an average=20 arrangement for a small garden plot like mine - but not the best) and = comparing=20 these with the reports last night when I was using just the 15m baseline = earth-electrode "antenna". I crudely plotted the "improvement factor" in = dB on a=20 polar plot. Each dot represents a station reporting my signal with the = dB=20 improvement over the earth-electrode antenna plotted on a 0-20dB scale = out from=20 the centre. This is not good science, it is G3XBM science I'm afraid, = but it=20 give a fair idea of the difference and how direction affects this (see = attached=20 rough polar plot).

Although in some directions the difference is = very=20 little, in other directions the reports are up to 14dB better on the=20 (omni-directional) Marconi.

My conclusion is that the earth = electrode=20 antenna is behaving somewhat like a loop with some directionality = along=20 the line of the earth-electrode baseline and a null off the sides. With = stations=20 receiving me off the sides there is most improvement with the Marconi, = and less=20 difference with stations end-on who were getting a reasonable signal = with the=20 earth-electrode antenna.

CONCLUSION: the simple, stealth,=20 earth-electrode antenna is a VERY useful antenna on 472kHz as long as = one is=20 prepared to accept a 2-14dB loss compared with a "small garden" = Marconi. In=20 all honesty, I am getting better reports on the Marconi but few new = stations are=20 copying me: most could copy me on the earth electrode antenna. =

I=20 shall run WSPR overnight to see if any more distant stations copy me, = then=20 probably put away the 472kHz gear and Marconi for a while to find = another=20 interesting challenge - possibly something on 10m or VHF.

These = last few=20 days have been fun, and that is really what this hobby is about.

73s
Roger G3XBM
--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
https://sites.google.com/= site/sub9khz/
http://qss2.blogspot.com/

<= /DIV>
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