Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-da03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 5230D38000084; Wed, 9 Jan 2013 16:24:01 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Tt369-0007qw-NW for rs_out_1@blacksheep.org; Wed, 09 Jan 2013 21:22:09 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Tt368-0007qj-Rd for rsgb_lf_group@blacksheep.org; Wed, 09 Jan 2013 21:22:08 +0000 Received: from nm3-vm0.bt.bullet.mail.ird.yahoo.com ([212.82.108.88]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1Tt366-0008I7-A7 for rsgb_lf_group@blacksheep.org; Wed, 09 Jan 2013 21:22:07 +0000 Received: from [212.82.108.230] by nm3.bt.bullet.mail.ird.yahoo.com with NNFMP; 09 Jan 2013 21:21:45 -0000 Received: from [77.238.189.18] by tm3.bt.bullet.mail.ird.yahoo.com with NNFMP; 09 Jan 2013 21:21:45 -0000 Received: from [127.0.0.1] by smtp818.mail.ird.yahoo.com with NNFMP; 09 Jan 2013 21:21:45 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=s1024; t=1357766505; bh=5t1shSZiUmJqH5bAshtoZgZTh8XbghNGUbe1c4K1O7I=; 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=4aDiSwatKj1IPgytzGhFCK8AKvCZuYdHA4ee6A8kbnuxx84sxHLFlY30Ptxo1Yw/vKE4CJB6vwUX25/nTFnfz2b5NpETNpXrQpzOoVAaxCgpLqisR3O9vpCcYR3rHGekGpf2LXgAl7D5AbghBX12pvM42CBDWJ4hpPQT13DTjfU= X-Yahoo-Newman-Id: 458918.65182.bm@smtp818.mail.ird.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: aIQxedIVM1niyppGvISm1E7dny8yotl5.UdmYCIXPYVkLQX 5PJS.NW7m1UBroVskpkVnjj7XDEzE93xnQfNcvnPIVtf.x0qmWPIph2SjwRZ P2nAW3M6qsolP7UoHawY1dlyhvYoAQoyyyPtOBMMFh.Qe5Ns9W1kXUb.4gZK ._vtPPzXXxHg76FLzqwHyhUPkJ7I.cLKfwwD4Qkr71KIcOG7s9DmFYnF5f5J 6ifsowjD4op.4UY1ISQ.d8K.s3a5dTfZkZFHbnMGT.M4KqnXGRacQNVuw.aH _.pR_2i5tQFpuU0yXnfTKnGUxRyEwwBjRKjgXytJumHcN1itVVDT6.dRoQAh Zww4IjNAJeyHL73z_TtOmRSvOjjn8unIxXtdNNGofd.5nbG4Z0ankls5kEGA q1WItWOzEnyWEoGaux_nxkigIfB2T9F.lDcqddYi9tJOWs5ez0IbGXRtputz .Ej80Y5qhHPJwlA2kBXED0NhfLkLMh0z_3WQ9H34OW1c42eTw4DV69mtuuyV JMa.vKeESoPK94MkjpDqHkpgCsX0IZdayjNYMNsS6qtrI8ThlFiqXTU_ZrQb Nk5Um523EVEKD.dEcZUolnEi88B4EHdCVqyhDMv47OjvlYzfdxXa8MP3ZHFA 5fTENipeEyTpsTX_wZW7Kg4kOvu1E0IiFJWwoODl1mFDZLJ4WUf5Hgtehp0a Ve9BGNxF4wCZuIfvXX5yjQEUa.AYx.iCusv5DbrVe6bd8ucYXoJNHGyRlsp3 NEAOyx46oRBP_Kg-- X-Yahoo-SMTP: fpz.2VeswBBs59bVshRPmMN51lcO2lgFRIvE4XTqE8dRwOxd70E- Received: from gnat (alan.melia@81.157.0.154 with login) by smtp818.mail.ird.yahoo.com with SMTP; 09 Jan 2013 21:21:45 +0000 UTC Message-ID: <92BB9448A06946099A4AAD993F1D80FC@gnat> From: "Alan Melia" To: References: <3401C753-302E-4621-9137-45B9A216D17F@gmail.com> <7E7DFBB4D102A04DB5ADC88D66628A4A0FB68393@ICTS-S-MBX5.luna.kuleuven.be> Date: Wed, 9 Jan 2013 18:01:00 -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 130109-0, 09/01/2013), Outbound message X-Antivirus-Status: Clean X-Spam-Score: 1.1 (+) 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 Rik if Roger was able to measure the Field Strength in the far field he could calculate "a" value for the ERP and a "virtual height".....that would be a nice parameter for an underground antenna :-)) Alan G3NYK [...] Content analysis details: (1.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.82.108.88 listed in list.dnswl.org] 1.1 DATE_IN_PAST_03_06 Date: is 3 to 6 hours before Received: date 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: 1d21af8b9fbb0623d7d37da24a04e495 Subject: LF: Re: RE: [rsgb_lf_group] Earth electrode antenna with wire at zero height (WSPR 472kHz) Content-Type: multipart/alternative; boundary="----=_NextPart_000_00E2_01CDEE93.482463C0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.4 required=5.0 tests=DATE_IN_PAST_03_06, FORGED_MUA_OUTLOOK,HTML_60_70,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-da03.r1000.mx.aol.com ; domain : btinternet.com DKIM : fail x-aol-sid: 3039ac1d404b50eddff01ded 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_00E2_01CDEE93.482463C0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Hi Rik if Roger was able to measure the Field Strength in the far field = he could calculate "a" value for the ERP and a "virtual height".....that = would be a nice parameter for an underground antenna :-)) Alan G3NYK ----- Original Message -----=20 From: Rik Strobbe=20 To: rsgb_lf_group@yahoogroups.co.uk ; rsgb_lf_group@blacksheep.org=20 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 same = antenna 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 given = antenna 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 A2). Again measure the relative ERP P2 (as before, using the same = WSPR RX stations at daytime). Now the total loop area is A1+A2, where we know A2 (the above ground = part) 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 = values of 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=20 -------------------------------------------------------------------------= ----- 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) =20 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 feeding the transverter straight into the rods without matching = suggesting low reactance and near 50 ohms.=20 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.=20 Will again leave it running overnight to get a decent number of spots = but already I think we have an answer.=20 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 the 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.=20 73s Roger G3XBM=20 __._,_.___ Reply to sender | Reply to group | Reply via web post | Start a new = topic=20 Messages in this topic (1)=20 Recent Activity: a.. New Members 8 a.. New Photos 1 a.. New Links 1=20 Visit Your Group=20 Switch to: Text-Only, Daily Digest =95 Unsubscribe =95 Terms of Use. =20 __,_._,___ ------=_NextPart_000_00E2_01CDEE93.482463C0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Hi Rik if Roger was able to measure the = Field=20 Strength in the far field he could calculate "a" value for the ERP and a = "virtual height".....that would be a nice parameter for an underground = antenna=20 :-))
Alan
G3NYK
 
----- Original Message -----
From:=20 Rik Strobbe
To: rsgb_lf_group@yahoogroups= .co.uk=20 ; rsgb_lf_group@blacksheep.org= =20
Sent: Wednesday, January 09, = 2013 4:45=20 PM
Subject: LF: RE: = [rsgb_lf_group] Earth=20 electrode antenna with wire at zero height (WSPR 472kHz)

Hello Roger,

 

assuming that the = underground=20 antenna behaves like a = loop:

For a classic loop area of = the loop=20 and=20 = the current flow are well=  defined=20 = (the current goes through=20 the wire =3D circumference of=20 the loop).

This is not the=20 case for the underground=20 = antenna, there will be<= A>=20 = a current flow through<= A> an area or=20 even a volume.

But one c= ould define the virtual=  area=20 of the underground antenna as the area of a classic = loop that procudes=20 the same ERP (with=20 the same antenna current) as the = underground=20 antenna.

But how=20 = to determine this virtual=20 loop area?

Suggestion:

You can m= easure=20 the relative ERP of your = underground=20 loop (at a given antenna=20 = current) using daytime WSPR=20 = and some local RX=20 station (daytime=20 = and local will rule<= /A>=20 out any propagation=20 changes).

Let's define=20 the virtual area of the = underground=20 antenna as A1 (m^2) and = the relative ERP=20 as P1 (=3D=20 dB values from=20 WSPR).

Next you = could raise=20 the wire, increasing the=20 loop area by=20 a know value=20 A2). Again measure = the relative ERP P2 (as=20 before, using=20 = the same WSPR RX= =20 stations at daytime).

Now the total= =20 loop area is = A1+A2, where=20 we know A2=20 (the above ground=20 = part) but not A1= =20 (the virtual underground part).

A1 can be= =20 calculated:

At a constant=20 antenna current the=20 = ERP will be proportional=20 to the square of the loop area.

So P1=20 is proportional to A1^2=20 and P2 is proportional 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 after some more=20 math:

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

So based = on=20 the ERP increase (P2/P1) and=20 = the above ground area=20 (A2) of the loop = the virtual area=20 (A1) of the "submerged"=20 part can be=20 calculated.

If this=20 = is done for some= =20 different heights of the wire = (=3D=20 different values of=20 A2) one would=20 = have an indication if this theory=20 is valid (the outcome of=20 = the virual area should<= A> be=20 more or less the=20 same).

 

73, = Rik  ON7YD=20 - OR7T 

 

 

Van: rsgb_lf_group@yahoogroups.co.uk=20 [rsgb_lf_group@yahoogroups.co.uk] namens Roger Lapthorn=20 [rogerlapthorn@gmail.com]
Verzonden: woensdag 9 januari 2013 = 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)

 =20

Ok, so as the final instalment of this test I have now got the = wires from=20 the earth rods coming to the transverter just resting on the wet grass = (what=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 = reactance=20 and near 50 ohms.

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

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

What I can try = next -=20 is this ever going to end!? - is elevate the loop part "in the air" 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 = effective area=20 is in the soil/rock.

WSPR spots please folks. =

73s
Roger=20 G3XBM

__._,_.___
Reply to sender | Reply to group | Reply via web = post |=20 Start a new topic
Messages in this topic (1)
Recent Activity:=20 New Members 8=20 New Photos 1=20 New Links 1
Visit Your Group
 =20
Switch to: Text-Only, Daily Digest =95 Unsubscribe =95 Terms of=20 Use
.
 
__,_._,___
------=_NextPart_000_00E2_01CDEE93.482463C0--