Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dc02.r1000.mx.aol.com (Internet Inbound) with ESMTP id A1A6638000083; Wed, 9 Jan 2013 07:25:03 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TsugN-0005Ej-5y for rs_out_1@blacksheep.org; Wed, 09 Jan 2013 12:22:59 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TsugL-0005Ea-SE for rsgb_lf_group@blacksheep.org; Wed, 09 Jan 2013 12:22:57 +0000 Received: from nm1-vm0.bt.bullet.mail.ukl.yahoo.com ([217.146.182.223]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1TsugI-00066U-PW for rsgb_lf_group@blacksheep.org; Wed, 09 Jan 2013 12:22:56 +0000 Received: from [217.146.183.196] by nm1.bt.bullet.mail.ukl.yahoo.com with NNFMP; 09 Jan 2013 12:22:33 -0000 Received: from [217.146.189.79] by tm2.bt.bullet.mail.ukl.yahoo.com with NNFMP; 09 Jan 2013 12:22:33 -0000 Received: from [127.0.0.1] by smtp829.mail.ird.yahoo.com with NNFMP; 09 Jan 2013 12:22:33 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=s1024; t=1357734153; bh=quOJ78JRa6CFcD758U20QzVP7dQYeRuMWjUHJ6Q9QZA=; h=X-Yahoo-Newman-Id:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MIMEOLE:X-Antivirus:X-Antivirus-Status; b=ITCfFGhm9QpkRvEDJazGIsiZ6OqeXxb+8LSVH6TDknF0ecik7MMLKJu9SPvyfOz6jbbnPVfzxu0ykZt9nExN60bWN9LKkf0ZPlIJLW9dl7nXrhTjqQxfQQLdt8YaIqLhprLnWHP21n/tujmVGN1ipyObbvtH8DQuVoa5r4qm2x0= X-Yahoo-Newman-Id: 882062.2138.bm@smtp829.mail.ird.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: ilimOhkVM1lIuN81rjgGxeMQW.g_z2p88cS10waZt5Mx7.a N3Fqn1PSJUeWQ6jOmnLKUk3LEdDnLxr4GyqT_gXuNpSFNkxovE0TrIzIFAze gD1622A8b3BOTnpvcXdQ7.S040sWxFGXtEEHvEAf5xXvJ5xsjzrPBYDsbH9k 6X98J8sebsAESzOuIJKhkkTVJ4bdyxTEe_N7hFVPqqupe022qjeYYYeOivKE UpUivm_qeLvWnsMV868gSay3mFxvaTun_Nk7fRKtdpngDuXXq9xfwfwNGD0F J7MJ.Wqxrbm5pPXVWQqNq9hO9i02HmnkSGEzRgPY2GPy2Gq.AdZY3hmcuH34 lsdEPUzyfzOez4ib8v_ygVuSyYyY8rNSU1K_1KoTGhB6zsRqGGFrt_agGGRt o14ItaMApCm8NJ._zRjKJ06SxBO74Q.5IhcwGxxL6WaaWmMbYaKszr4qh6u_ UlwjqYbrzYMlr5uqs1HwnJBcoGT5qY52zllMSDtxUPguEJjsNgFE2..DDYOH g2T3U_FJxWEwzFlWquxcaTow8LlKKPdTKuXKd9w7MDx0SFsyUFjwV867gFO1 Uq4_sNMzuzVylMVwoND3XHpmpNsOIztiTe3YGEFt2voCpqRM8FN0Hu62Oss3 Qzh1QH2pgdFdRtbqtOMC2eHYTyqBPjOnRFodT4SPS7a5Ke0MveM4Yys4uGXs epnJ.uw9p.nRSfw0.oe_cb5PQSKNi4Ap9Ip9UoYTZ0Kguum7EHsa7iFgOhdi TGA-- X-Yahoo-SMTP: fpz.2VeswBBs59bVshRPmMN51lcO2lgFRIvE4XTqE8dRwOxd70E- Received: from gnat (alan.melia@81.157.0.154 with login) by smtp829.mail.ird.yahoo.com with SMTP; 09 Jan 2013 04:22:33 -0800 PST Message-ID: From: "Alan Melia" To: References: <8EFF74C5288B4CC1B0776D52DBE13A77@gnat> Date: Wed, 9 Jan 2013 12:06:16 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-Antivirus: avast! (VPS 130108-1, 08/01/2013), Outbound message X-Antivirus-Status: Clean 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: Hi Graham could be, there are lots of "explanations" as to how the K9AY and "Flag" are supposed to work, also Beverages that aren't actually Beverages but long lengths of low wire :-)). Alan ----- Original Message ----- From: Graham To: rsgb_lf_group@blacksheep.org Sent: Wednesday, January 09, 2013 1:10 AM Subject: Re: LF: Re: Comparing earth-electrode v. Marconi antenna on 472kHz [...] 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 [217.146.182.223 listed in list.dnswl.org] 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines X-Scan-Signature: b322dc0956bb435e223041a6879534f9 Subject: Re: LF: Re: Comparing earth-electrode v. Marconi antenna on 472kHz Content-Type: multipart/alternative; boundary="----=_NextPart_000_0050_01CDEE61.BA324EF0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.1 required=5.0 tests=FORGED_MUA_OUTLOOK,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-AUTHENTICATION: mtain-dc02.r1000.mx.aol.com ; domain : btinternet.com DKIM : pass x-aol-sid: 3039ac1d408250ed619e780a 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_0050_01CDEE61.BA324EF0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Graham could be, there are lots of "explanations" as to how the K9AY = and "Flag" are supposed to work, also Beverages that aren't actually = Beverages but long lengths of low wire :-)). Alan ----- Original Message -----=20 From: Graham=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Wednesday, January 09, 2013 1:10 AM Subject: Re: LF: Re: Comparing earth-electrode v. Marconi antenna on = 472kHz Could be on the grounds of part of a magnetic loop , where = the circuiting current is bolstered by the 'diffused ' return = path , I was thinking of the high level of circulating currant = causing the radiation as opposed to a 'wave size' array =20 G.. From: Alan Melia=20 Sent: Wednesday, January 09, 2013 12:10 AM To: rsgb_lf_group@blacksheep.org=20 Subject: LF: Re: Comparing earth-electrode v. Marconi antenna on = 472kHz There is nothing wrong with the "science" of doing simple experiments = Roger ......The bad science is if you try to read too much into = them......which you have not done. Your results do align with the books = in the subject though most are for ELF. It doesnt work this way for = everyone it depends on local ground conditions.....thats why there is = always so much discussion :-))=20 I cant remember the detail but the skin depth of your ground at 500k = is probablty quite shallow but it probably could still be several feet = giving a reasonable area loop, and the conductivity must be quite good. Graham's idea of a TWA is feasible but I think it is too short(normal = requirement 300 to 900 m) to have directionality, not terminated, and = too low ar this frequency. TWAs usually work best on receive over poor = ground and would very inefficient as transmitting aerials. But any bit = of wire will act as an aerial and there is no guarantee there is a = single mode of operation :-)) Alan G3NYK ----- Original Message -----=20 From: Roger Lapthorn=20 To: rsgb_lf_group@blacksheep.org ; rsgb_lf_group@yahoogroups.co.uk=20 Sent: Tuesday, January 08, 2013 9:06 PM 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_0050_01CDEE61.BA324EF0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Graham could be, there are lots of=20 "explanations" as to how the K9AY and "Flag" are supposed to work, also=20 Beverages that aren't actually Beverages but long lengths of low wire=20 :-)).
Alan
----- Original Message -----
From:=20 Graham
Sent: Wednesday, January 09, = 2013 1:10=20 AM
Subject: Re: LF: Re: Comparing=20 earth-electrode v. Marconi antenna on 472kHz

Could  be  on the  grounds  of  part of = a =20 magnetic  loop  , where  the  circuiting =20 current  is  bolstered  by the  'diffused '   =    return  path ,  I was thinking of the  = high =20 level  of  circulating  currant   = causing =20 the  radiation as  opposed to  a 'wave  = size' =20 array    
 
G..

From: Alan Melia
Sent: Wednesday, January 09, 2013 12:10 AM
To: rsgb_lf_group@blacksheep.org= =20
Subject: LF: Re: Comparing earth-electrode v. Marconi = antenna on=20 472kHz

There is nothing wrong with the = "science" of=20 doing simple experiments Roger ......The bad science is if you try to = read too=20 much into them......which you have not done. Your results do align = with the=20 books in the subject though most are for ELF. It doesnt work this way = for=20 everyone it depends on local ground conditions.....thats why there is = always=20 so much discussion :-))
 
I cant remember the detail but the = skin depth of=20 your ground at 500k is probablty quite shallow but it probably could = still be=20 several feet  giving a reasonable area loop, and the conductivity = must be=20 quite good.
 
Graham's idea of a TWA is feasible = but I think it=20 is too short(normal requirement 300 to 900 m) to have directionality,=20 not  terminated, and too low ar this frequency. TWAs usually work = best on=20 receive over poor ground and would very inefficient as = transmitting=20 aerials. But any bit of wire will act as an aerial and there is no = guarantee=20 there is a single mode of operation :-))
 
 
Alan
G3NYK
----- Original Message -----
From:=20 Roger=20 Lapthorn
To: rsgb_lf_group@blacksheep.org= =20 ; rsgb_lf_group@yahoogroups= .co.uk=20
Sent: Tuesday, January 08, = 2013 9:06=20 PM
Subject: LF: Comparing = earth-electrode=20 v. Marconi antenna on 472kHz

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

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

My=20 conclusion is that the earth electrode antenna is behaving = somewhat=20 like a loop with some directionality along the line of the = earth-electrode=20 baseline and a null off the sides. With stations receiving me off = the sides=20 there is most improvement with the Marconi, and less 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.=20 In all honesty, I am getting better reports on the Marconi but few = new=20 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=20 copy me, then probably put away the 472kHz gear and Marconi for a = while to=20 find another interesting challenge - possibly something on 10m or = VHF.=20

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