Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mi05.r1000.mx.aol.com (Internet Inbound) with ESMTP id D5125380000CD; Wed, 9 Jan 2013 16:31:04 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Tt3DR-00085D-SL for rs_out_1@blacksheep.org; Wed, 09 Jan 2013 21:29:41 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Tt3DQ-000854-W8 for rsgb_lf_group@blacksheep.org; Wed, 09 Jan 2013 21:29:40 +0000 Received: from mail-qa0-f53.google.com ([209.85.216.53]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.77) (envelope-from ) id 1Tt3DN-0008Pg-93 for rsgb_lf_group@blacksheep.org; Wed, 09 Jan 2013 21:29:39 +0000 Received: by mail-qa0-f53.google.com with SMTP id a19so1080119qad.5 for ; Wed, 09 Jan 2013 13:29:14 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=5ELyw4kmoxR0E8cXYM0tkZkL4xODui/GOVEf4Ly6ctQ=; b=iPrhOUVy/TYFT2tTfldnYfVwK/5YG5T2nPdOUpl8uC5ThudY6G2TvgHbJyEPQMzlj5 /tJlMXj6LHUNcEB/hixTTunZDz8W0igaSjfhReeiKHJrxDiwLKTb7ld1wTZCvib9KA/p jIvK+ZQuQze9P9vGygf4D41s+tqPthIUYbYbqsTrYSg6WymYDg71Pfo97RcdZUp3bIGD aTMzNXJk0PufoBc1P5SHiaxGd52pt/Ma7U9BPAn+FA55ZCzKwespKmpIX++32JF9hkbH 6XNjwwWWqfPgUHdCExPc2dmcXwk+Yz20Ggan3GVdI53ciBfToHbax7HYZfgZVHkDGDhC D4dA== MIME-Version: 1.0 Received: by 10.224.179.67 with SMTP id bp3mr45870088qab.7.1357766954447; Wed, 09 Jan 2013 13:29:14 -0800 (PST) Received: by 10.229.156.18 with HTTP; Wed, 9 Jan 2013 13:29:14 -0800 (PST) In-Reply-To: <92BB9448A06946099A4AAD993F1D80FC@gnat> References: <3401C753-302E-4621-9137-45B9A216D17F@gmail.com> <7E7DFBB4D102A04DB5ADC88D66628A4A0FB68393@ICTS-S-MBX5.luna.kuleuven.be> <92BB9448A06946099A4AAD993F1D80FC@gnat> Date: Wed, 9 Jan 2013 21:29:14 +0000 Message-ID: From: Roger Lapthorn To: "rsgb_lf_group@blacksheep.org" X-Spam-Score: -0.7 (/) 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: See the conclusions of this work summarised on my blog at < http://g3xbm-qrp.blogspot.co.uk/2013/01/earth-electrode-antenna-conclusions.html >. I am totally amazed how well this thing works, considering how utterly simple it is! [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.216.53 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (rogerlapthorn[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_OBFUSCATE_05_10 BODY: Message is 5% to 10% HTML obfuscation 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 4547f2cca70c75b03fc1ebaed398eea1 Subject: Re: LF: Re: RE: [rsgb_lf_group] Earth electrode antenna with wire at zero height (WSPR 472kHz) Content-Type: multipart/alternative; boundary=20cf3033441901f39b04d2e1c179 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_40_50,HTML_MESSAGE, TO_ADDRESS_EQ_REAL 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-mi05.r1000.mx.aol.com ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d7b8d50ede198466f X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --20cf3033441901f39b04d2e1c179 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable See the conclusions of this work summarised on my blog at < http://g3xbm-qrp.blogspot.co.uk/2013/01/earth-electrode-antenna-conclusions= .html >. I am totally amazed how well this thing works, considering how utterly simple it is! Work now concluding. New challenge needed, HI. 73s Roger G3XBM On 9 January 2013 18:01, Alan Melia wrote: > ** > Hi Rik if Roger was able to measure the Field Strength in the far field h= e > could calculate "a" value for the ERP and a "virtual height".....that wou= ld > be a nice parameter for an underground antenna :-)) > Alan > G3NYK > > > ----- Original Message ----- > *From:* Rik Strobbe > *To:* rsgb_lf_group@yahoogroups.co.uk ; rsgb_lf_group@blacksheep.org > *Sent:* Wednesday, January 09, 2013 4:45 PM > *Subject:* LF: RE: [rsgb_lf_group] Earth electrode antenna with wire at > zero height (WSPR 472kHz) > > Hello Roger, > > > > assuming that the underground antenna behaves like a loop: > > For a classic loop area of the loop and the current flow are well defined= (the current > goes through the wire =3D circumference of the loop). > > This is not the case for the underground antenna, there will be a current > flow through an area or even a volume. > > But one could define the virtual area of the underground antenna as > the area of a classic loop that procudes the same ERP (with the sameanten= na current) > as the underground antenna. > > But how to determine this virtual loop area? > > Suggestion: > > You can measure the relative ERP of your underground loop (at a givenante= nna current > ) using daytime WSPR and some local RX station (daytime and local will > rule out any propagation changes). > > Let's define the virtual area of the underground antenna as A1 (m^2) and > the relative ERP as P1 (=3D dB values from WSPR). > > Next you could raise the wire, increasing the loop area by a know value A= 2 > ). Again measure the relative ERP P2 (as before, using the same WSPR RXst= ations at daytime > ). > > Now the total loop area is A1+A2, where we know A2 (the above groundpart)= but > not A1 (the virtual underground part). > > A1 can be calculated: > > At a constant antenna current the ERP will be proportional to the square > of the loop area. > > So P1 is proportional to A1^2 and P2 is proportional to (A1+A2)^2. > > Or: P2/P1 =3D (A1+A2)^2/A1^2 =3D (A1^2+2*A1*A2+A2^2)/A1^2 > > And after some more math: > > A1 =3D ((1+sqrt(P2/P1))/((P2/P1)-1))*A2. > > So based on the ERP increase (P2/P1) and the above ground area (A2) of > the loop the virtual area (A1) of the "submerged" part can be calculated. > > If this is done for some different heights of the wire (=3D different val= uesof A2 > ) one would have an indication if this theory is valid (the outcome of > the virual area should be more or less the same). > > > > 73, Rik ON7YD - OR7T > > > > > ------------------------------ > *Van:* rsgb_lf_group@yahoogroups.co.uk [rsgb_lf_group@yahoogroups.co.uk] > namens Roger Lapthorn [rogerlapthorn@gmail.com] > *Verzonden:* woensdag 9 januari 2013 15:54 > *To:* rsgb_lf_group@blacksheep.org; rsgb_lf_group@yahoogroups.co.uk > *Onderwerp:* [rsgb_lf_group] Earth electrode antenna with wire at zero > height (WSPR 472kHz) > > > > Ok, so as the final instalment of this test I have now got the wires from > the earth rods coming to the transverter just resting on the wet grass > (what was elevated by 1.5m is now zero). It seems to work best just feedi= ng > the transverter straight into the rods without matching suggesting low > reactance and near 50 ohms. > > I'm still getting decent reports! So, it confirms the "loop in the ground= " > theory, or it is acting as some bizarre E field antenna. > > Will again leave it running overnight to get a decent number of spots but > already I think we have an answer. > > What I can try next - is this ever going to end!? - is elevate the loop > part "in the air" to much greater height (about 9m to match the top of th= e > Marconi I just took down) and see how much improvement I get. More in the > air implies greater loop area so more signal. Just how much will indicate > how much of the loop's effective area is in the soil/rock. > > WSPR spots please folks. > > 73s > Roger G3XBM > __._,_.___ > Reply to sender| Re= ply > to group| Re= ply > via web post| Start > a new topic > Messages in this topic( > 1) > Recent Activity: > > - New Members > 8 > - New Photos > 1 > - New Links > 1 > > Visit Your Group > [image: Yahoo! Groups] > Switch to: Text-Only, > Daily Digest=95 > Unsubscribe=95 Terms > of Use > . > > __,_._,___ > > --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk https://sites.google.com/site/sub9khz/ http://qss2.blogspot.com/ --20cf3033441901f39b04d2e1c179 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
See the conclusions of this work summa= rised on my blog at <http://g3xbm-qrp.blogspot.co.uk/2= 013/01/earth-electrode-antenna-conclusions.html>.

I am totally amazed how well this thing works, considering how ut= terly simple it is!

Work now concluding. New challenge needed,= HI.

73s
Roger G3XBM


On 9 January 2013 18:01, Alan Melia <alan.melia@btinternet.com> wrote:
Hi Rik if Roger was able to measure the Field=20 Strength in the far field he could calculate "a" value for the ER= P and a=20 "virtual height".....that would be a nice parameter for an underg= round antenna=20 :-))
Alan
G3NYK
=A0
----- Original Message -----
From:=20 Rik Strobbe
Sent: Wednesday, January 09, 2013 4= :45=20 PM
Subject: LF: RE: [rsgb_lf_group] Ea= rth=20 electrode antenna with wire at zero height (WSPR 472kHz)

Hello=A0Rog= er,

=A0

assuming=A0= that the underground=20 antenna=A0behaves=A0like a loop:

For a=A0classic loop=A0area of the loop=20 and=20 the=A0current=A0flow=A0are=A0well=A0defined=20 (the=A0current=A0goes=A0through= =20 the=A0wire =3D=A0circumference of=20 the loop).

= This=A0is=A0not the=20 case=A0for=A0the underground=20 antenna,=A0there=A0will=A0be=20 a=A0current=A0flow=A0through=A0= an=A0area=A0or=20 even a volume.

= But=A0one=A0could= =A0define=A0the=A0virtual=A0area<= /a>=20 of the underground antenna as the=A0area of a classic=20 loop=A0that=A0procudes=20 the=A0same ERP (with=20 the=A0same antenna current) as the undergroun= d=20 antenna.

= But=A0how=20 to=A0determine=A0this=A0virtual= =20 loop area?

= Suggestion:

= You=A0can=A0measure<= a>=20 the=A0relative ERP of=A0your underground=20 loop (at a=A0given antenna=20 current)=A0using=A0daytime=A0WS= PR=20 and=A0some=A0local=A0RX=20 station (daytime=20 and=A0local=A0will=A0rule=20 out=A0any=A0propagation=20 changes).

= Let's=A0define=20 the=A0virtual=A0area of the underground=20 antenna as=A0A1 (m^2) and the=A0relative ERP= =20 as=A0P1 (=3D=20 dB=A0values=A0from=20 WSPR).

= Next=A0you=A0could=A0raise=20 the wire,=A0increasing the=20 loop=A0area=A0by=20 a=A0know=A0value=20 A2).=A0Again=A0measure=20 the=A0relative ERP=A0P2 (as=20 before,=A0using=20 the=A0same=A0WSPR=A0RX=20 stations at daytime).

= Now=A0the=A0total=20 loop=A0area is A1+A2,=A0where= =20 we=A0know=A0A2=20 (the=A0above=A0ground=20 part)=A0but=A0not=A0A1=20 (the=A0virtual underground part).

= A1=A0can=A0be= =20 calculated:

At a constant=20 antenna=A0current the=20 ERP=A0will=A0be=A0proportional= =20 to the square of the loop area.

= So=A0P1=20 is=A0proportional to A1^2=20 and=A0P2 is=A0proportional to=20 (A1+A2)^2.

= Or: P2/P1 =3D=20 (A1+A2)^2/A1^2 =3D=20 (A1^2+2*A1*A2+A2^2)/A1^2

And=A0after=A0some more=20 math:

= A1=A0=3D=20 ((1+sqrt(P2/P1))/((P2/P1)-1))*A2.

= So=A0based=A0on=20 the ERP=A0increase (P2/P1) and=20 the=A0above=A0ground=A0area=20 (A2) of the loop the=A0virtual=A0area= =20 (A1) of the "submerged"=20 part=A0can=A0be=20 calculated.

= If=A0this=20 is=A0done=A0for=A0some=20 different=A0heights of the=A0wire (=3D=20 different=A0values of=20 A2)=A0one=A0would=20 have=A0an=A0indication=A0if=A0t= his=A0theory=20 is=A0valid (the=A0outcome of=20 the=A0virual=A0area=A0should=A0= be=20 more=A0or=A0less the=20 same).

=A0

73, Rik=A0=A0ON7YD=20 -=A0OR7T=A0

=A0

=A0

V= an: rsgb_lf_group@yahoogroups.co.uk=20 [rsg= b_lf_group@yahoogroups.co.uk] namens Roger Lapthorn=20 [rogerlaptho= rn@gmail.com]
Verzonden: woensdag 9 januari 2013=20 15:54
To: rsgb_lf_group@blacksheep.org;=20 rsgb= _lf_group@yahoogroups.co.uk
Onderwerp: [rsgb_lf_group] Earth= =20 electrode antenna with wire at zero height (WSPR 472kHz)

=A0=20

Ok, so as the final instalment of this test I have now got the wires f= rom=20 the earth rods coming to the transverter just resting on the wet grass (w= hat=20 was elevated by 1.5m is now zero). It seems to work best just feeding the= =20 transverter straight into the rods without matching suggesting low reacta= nce=20 and near 50 ohms.

I'm still getting decent reports! So, it co= nfirms=20 the "loop in the ground" theory, or it is acting as some bizarr= e E field=20 antenna.

Will again leave it running overnight to get a decent nu= mber=20 of spots but already I think we have an answer.

What I can try ne= xt -=20 is this ever going to end!? - is elevate the loop part "in the air&q= uot; to much=20 greater height (about 9m to match the top of the Marconi I just took down= ) and=20 see how much improvement I get. More in the air implies greater loop area= so=20 more signal. Just how much will indicate how much of the loop's effec= tive area=20 is in the soil/rock.

WSPR spots please folks.

73s
Roge= r=20 G3XBM

__._,_.___
Recent Activity:=20
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=A0
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=20



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http://www.g3xbm.co.uk
https://sites.google.com/site/sub9khz/
http://qss2.blogspot.com/

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