Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-da02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 0B97A38000091; Wed, 11 Apr 2012 12:43:37 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SI0cl-0003gM-6E for rs_out_1@blacksheep.org; Wed, 11 Apr 2012 17:42:27 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SI0ck-0003gD-EF for rsgb_lf_group@blacksheep.org; Wed, 11 Apr 2012 17:42:26 +0100 Received: from nm8.bullet.mail.ird.yahoo.com ([77.238.189.23]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1SI0ci-0000Sc-VN for rsgb_lf_group@blacksheep.org; Wed, 11 Apr 2012 17:42:26 +0100 Received: from [77.238.189.233] by nm8.bullet.mail.ird.yahoo.com with NNFMP; 11 Apr 2012 16:42:19 -0000 Received: from [212.82.108.227] by tm14.bullet.mail.ird.yahoo.com with NNFMP; 11 Apr 2012 16:42:19 -0000 Received: from [127.0.0.1] by omp1004.bt.mail.ird.yahoo.com with NNFMP; 11 Apr 2012 16:42:19 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 54219.19615.bm@omp1004.bt.mail.ird.yahoo.com Received: (qmail 37806 invoked by uid 60001); 11 Apr 2012 16:42:19 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=s1024; t=1334162538; bh=K83dsRzH+YK5u+hb6iCU1/NKW7PHHnv2hQHsIzivXLg=; h=X-YMail-OSG:Received:X-Mailer:Message-ID:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=LIFUW572oEadHe5POGp4EfC3ghOY1NqBM4uYgy1w4ws1ZsQD62iCyC9wWi8FdE4qVFWp1auaH4VuDP2We3Qknvknkzisnh88KwAXcgM4kPXlZske0jeSFfXhP1PmQrWHdq0QaeAhRDRoaoRoqJ1WQuhdd6oHy0NmpDjQquhsXUg= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=X-YMail-OSG:Received:X-Mailer:Message-ID:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=LrJsTcQJs3QQSQgQ1Q33YEgXuRYofJEOByXUhtZcSLWHlMmhEKOQ4HjwlfThuriH4PT7OLmbxQSoWsrNE1+8pfunrLFRMjy91JRJpVC0wCdIOMEyi3SDUev+sFEISXZ5lWmr71/v1Wwdh+Z8yO/N1XfzaliaM0Y6scN/dkvO6+o=; X-YMail-OSG: pw6XWBkVM1nS1FYvAqSgyZ7OBJ4jm.xyAWGbCOxkp7SWMx6 mA7c9BH8bEjxgDndl0Vc9jRsOQ_9naXI1jS2IXNUwL9QgYeAyynwyhym67b5 vGy4AmsB3wy74Y_48YtKhlT1qmQ_gFGYsSkSA9JynDxsUDo54oOGs65CDws7 N9IfqFHdia71SeqkBn6oYR0Sfg2oZDxBUnME8JlyNnlMZld9p5UXQdH9PjhK 9ursrHq4mMj2U4NGxahMhwgdfEEgW37eMAK61pTEfep9DO6F4DbWxj4lRaqa otT6_ERJQIMPw_C4au2gK0_IQgiuKg93cl6hA1sRIsCJLOIyqzgMObUNo.Wb xzrgla4fnwt_e7esHGgtNHiQuEyRHEDkefj8cS9Zf5D43eIgyvpSwoHBxvic UjWJ61Ay4vpVzefEr8tt5M.54QGsVZ53pzFRaNWCloB3K15wfysBC3FgaF_x Cy3ypKokXTwV_dGpYpYn7XTsnF.sq6aYgYVszNPj5KqjkmQNZeAdhTcX.X0S rf7OyQq9Ob35vYDrmNi7zOXzjjmKGfu17akUb33CoU1AB0OtYuOqEODCkPUk pOwSs Received: from [109.155.42.60] by web87403.mail.ir2.yahoo.com via HTTP; Wed, 11 Apr 2012 17:42:18 BST X-Mailer: YahooMailClassic/15.0.5 YahooMailWebService/0.8.117.340979 Message-ID: <1334162538.37672.YahooMailClassic@web87403.mail.ir2.yahoo.com> Date: Wed, 11 Apr 2012 17:42:18 +0100 (BST) From: ALAN MELIA To: rsgb_lf_group@blacksheep.org In-Reply-To: <4F85ABD4.3080503@iup.uni-heidelberg.de> MIME-Version: 1.0 DomainKey-Status: good (testing) X-Spam-Score: 0.1 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,HTML_TAG_EXIST_TBODY=0.126 Subject: Re: LF: Earth antennas, Beverages... Content-Type: multipart/alternative; boundary="1933340020-1596808829-1334162538=:37672" 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, HTML_TAG_EXISTS_TBODY 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-SCORE: 1:2:496916128:93952408 X-AOL-SCOLL-URL_COUNT: 1 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d267.1 ; domain : btinternet.com DKIM : pass x-aol-sid: 3039ac1d404a4f85b4b851a3 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : temperror --1933340020-1596808829-1334162538=:37672 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi Stefan I have a saying that "any bit of wire will act as an antenna.....= ..but the real question is one of efficiency!"=A0 :-))=A0 There is no doubt= a good long one will beat a good short one! (....antennas, I mean .....) Alan --- On Wed, 11/4/12, Stefan Sch=E4fer wrote: From: Stefan Sch=E4fer Subject: Re: LF: Earth antennas, Beverages... To: rsgb_lf_group@blacksheep.org Date: Wednesday, 11 April, 2012, 17:05 =0A=0A=0A=0A =0A=0AHi Alan, =0AAm 11.04.2012 17:23, schrieb ALAN MELIA:=0A=0A =0A =0A =0A = Interesting Stefan........though I am not sure it is=0Aactually working = as a Beverage, They are usually quoted as being=0Abetween a=A0 half and one= and a half wavelengths long=0A =0A =0A =0A=0AYes, sri, the word i= s wrongly used here. I think the name is used since=0Aamateur stations use = such an antenna on HF too, where it acts as a=0Abeverage. On LF it is to sh= ort to use that name. =0A =0A73, Stefan =0A =0A=0A =0A =0A =0A .....but they are travelling wave antenn= as. Marconi=0Astations used to lay out an insulated with on the ground abou= t 5 to 10=0Akm long in the direction of the transmitting station. This had = no=0A"effective height" at higher frequency interference, whereas the skin= =0Adepth was significant particularly in "poor" ground at VLF.=A0 My "take"= =0Ais that they are all coupling loops, coupling to the Earth Ionosphere=0A= waveguide.....in essence the K9AY works the same way I think.=0ATermination= makes them unidirectional. Loads to play with :-)) =0A =20 =0AAlan =0A=A0 =0A =20 =0A--- On Wed, 11/4/12, Stefan Sch=E4fer =0Awrote: =0A =20 =0AFrom: Stefan Sch=E4fer =0ASubject: LF: Earth antennas, Beverages... =0ATo: vk2ddi@internode.on.net =0ACc: "Dimitrios Tsifakis" , "Bob"=0A, "Edgar J Twining"=0A,=0Arsg= b_lf_group@blacksheep.org =0ADate: Wednesday, 11 April, 2012, 14:12 =0A =20 =0A =0A Hi David,=20 =0A =20 =0ASorry for my late reply about your beverage antenna mail. =0A =20 =0AThanks for your point of view to the beverage antennas and the=0Apicture= s. That sounds all very interesting and i can imagine about the=0Ahigh sign= al levels coming from such a antenna. The problem in Germany=0Ais o find a = place which is far away from man made noise sources and=0Aallow to hung up = such a long wire. =0A =20 =0ABut i have found such a place! :-) However i didn't spend much time and= =0Ainterest to it regarding receive possibilities. I'm just getting=0Are-in= spired by thinking of it. It is in a very quiet location! =0A =20 =0AIn the forest of Heidelberg in JN49IK77 i hung up a 700m long wire. It= =0Ais called my earth antenna. The main intention is and was to transmit=0A= on VLF on this antenna. The far end is grounded by 20 or 30 earth rods,=0A4= 0cm deep and about 1m separated. The same on the other end. This forms=0Aa = loop where the current flows back through the earth. The lower the=0Afreque= ncy and the lower the ground conductivity, the deeper the return=0Apath of = the current, so the bigger the cross section area and the=0Ahigher the effi= ciency. =0AThat region is a hill/mountain about 500m ASL and 400m above the local= =0Aground in some km distance. The ground is out of stone with a layer of= =0Asoil, about 30cm. The need for a poor ground conductivity stands in=0Aop= posite to the wanted low loop resistance, which means the need for=0Ahigh e= ffort on the grounding at each end, i.e. a high number of ground=0Arods. Al= so the wire length is very important. =0AAnyway the efficiency will be poor but anyway you have a most seldom=0Aa= nd interesting transmit antenna whioch is not=0Aresonated, thus it is possi= ble to transmit on any frequency. I'm also=0Alooking forward to the 500 kHz= allocation. It will be nice to use it as=0Aa receive and transmit antenna = on 475 kHz. =0AIn summer when it is dry i achieved a loop resistance arround 800 Ohm,= =0Awhich is coming from the grounding losses dominantly. I've done several= =0Atransmit tests and achieved 35 dB S/N in 4.5 mHz in a distance of 5 km,= =0Ato my own VLF grabber.=20 =0ADuring the first times where the antenna was still shorter a wrote a=0As= hort report with some pictures:=0A http://dl.dropbox.com/u/1988202= 8/VLF/VLF_5km_with_an_earth_antenna.pdf =0ATests with Michael Oexner (SWL, NDB hunter) in 49 km were positive too,= =0Ain DFCW-600, see the attached Mail from 2010. BTW this is a VERY good=0A= demonstration of the positive effect of band limiting, clipping and=0Anoise= blanking of the VLF signals processed in SpecLab. The picture=0Ashown my s= ignal with and without the SpecLabs noise reduction technics.=0AThis 49km d= istance in 4.5 mHz=A0 is the current record with an earth=0Aantenna. The tr= ansmit power was 200...250 watts if i remember correctly. =0A =20 =0AI will check if the antenna still exists and will refurbish it. Also i= =0Awill do new tests there. BTW i've done a recording on VLF using this=0Aa= ntenna in January, 29th 2011, if someone wants to play with it (1 GB):=0A = http://dl.dropbox.com/u/19882028/VLF/29012011_12UTC_earth%20antenna= _recording.WAV =0A =20 =0AIn VK it seems you can easily arrange such an antenna, maybe even=0Aacro= ss a stony hill and grounded into the sea at one end. You just need=0Asome = wire and a portable PA :-) BTW this is the PA i was using:=0A http= ://www.iup.uni-heidelberg.de/schaefer_vlf/12V_300W_VLF_PA.pdf =0A =20 =0A73, Stefan/DK7FC =0A =0A =0A =0A =0A =0A =0A =0A=0A= =0A --1933340020-1596808829-1334162538=:37672 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hi Stefan I have a saying that "any bit of wi= re will act as an antenna.......but the real question is one of efficiency!= "  :-))  There is no doubt a good long one will beat a good short= one! (....antennas, I mean .....)

Alan

--- On Wed, 11/4/1= 2, Stefan Sch=E4fer <Stefan.Schaefer@iup.uni-heidelberg.de> wrote:

From: Stefan Sch=E4fer <Stefan.= Schaefer@iup.uni-heidelberg.de>
Subject: Re: LF: Earth antennas, Beve= rages...
To: rsgb_lf_group@blacksheep.org
Date: Wednesday, 11 April, = 2012, 17:05

=0A=0A=0A=0A =0A
=0AHi Ala= n,
=0AAm 11.04.2012 17:23, schrieb ALAN MELIA:=0A
=0A =0A =0A =0A =0A =0A =0A
Inte= resting Stefan........though I am not sure it is=0Aactually working as a Be= verage, They are usually quoted as being=0Abetween a  half and one and= a half wavelengths long
=0A<= /blockquote>=0AYes, sri, the word is wrongly used here. I think the name is= used since=0Aamateur stations use such an antenna on HF too, where it acts= as a=0Abeverage. On LF it is to short to use that name.
=0A
=0A73, S= tefan
=0A
=0A
=0A =0A =0A =0A =0A =0A =0A
.....but they are travelling wave ant= ennas. Marconi=0Astations used to lay out an insulated with on the ground a= bout 5 to 10=0Akm long in the direction of the transmitting station. This h= ad no=0A"effective height" at higher frequency interference, whereas the sk= in=0Adepth was significant particularly in "poor" ground at VLF.  My "= take"=0Ais that they are all coupling loops, coupling to the Earth Ionosphe= re=0Awaveguide.....in essence the K9AY works the same way I think.=0ATermin= ation makes them unidirectional. Loads to play with :-))
=0A
= =0AAlan
=0A 
=0A
=0A--- On Wed, 11/4/12, Stefan Sc= h=E4fer <Stefan.= Schaefer@iup.uni-heidelberg.de>=0Awrote:
=0A
=0AFrom: Stefan Sch=E4fer <Stefan.Schaefer@iup.uni-heidelberg.de>
=0ASubject: LF: Earth antennas, Beverages...
=0ATo: vk2ddi@internode.on.net
=0ACc: "Dimitrios Tsifakis" <dtsifakis@gmail.com>, "Bob"=0A<vk7zl@internode.on.net>, "Edgar J Twining"=0A<edgarjtwining@virginbroadband.com.a= u>,=0Arsgb_lf_group@blacksheep= .org
=0ADate: Wednesday, 11 April, 2012, 14:12
=0A
= =0A
=0A
Hi David,
=0A =
=0ASorry for my late reply about your beverage antenna mail.=0A
=0AThanks for your point of view to the beverage antennas= and the=0Apictures. That sounds all very interesting and i can imagine abo= ut the=0Ahigh signal levels coming from such a antenna. The problem in Germ= any=0Ais o find a place which is far away from man made noise sources and= =0Aallow to hung up such a long wire.
=0A
=0ABut i have fou= nd such a place! :-) However i didn't spend much time and=0Ainterest to it = regarding receive possibilities. I'm just getting=0Are-inspired by thinking= of it. It is in a very quiet location!
=0A
=0AIn the fores= t of Heidelberg in JN49IK77 i hung up a 700m long wire. It=0Ais called my e= arth antenna. The main intention is and was to transmit=0Aon VLF on this an= tenna. The far end is grounded by 20 or 30 earth rods,=0A40cm deep and abou= t 1m separated. The same on the other end. This forms=0Aa loop where the cu= rrent flows back through the earth. The lower the=0Afrequency and the lower= the ground conductivity, the deeper the return=0Apath of the current, so t= he bigger the cross section area and the=0Ahigher the efficiency.
=0ATha= t region is a hill/mountain about 500m ASL and 400m above the local=0Agroun= d in some km distance. The ground is out of stone with a layer of=0Asoil, a= bout 30cm. The need for a poor ground conductivity stands in=0Aopposite to = the wanted low loop resistance, which means the need for=0Ahigh effort on t= he grounding at each end, i.e. a high number of ground=0Arods. Also the wir= e length is very important.
=0AAnyway the efficiency will be poor but an= yway you have a most seldom=0Aand interesting transmit antenna whioch is not=0Aresonated, thus it is possible to transmit on any frequen= cy. I'm also=0Alooking forward to the 500 kHz allocation. It will be nice t= o use it as=0Aa receive and transmit antenna on 475 kHz.
=0AIn summer wh= en it is dry i achieved a loop resistance arround 800 Ohm,=0Awhich is comin= g from the grounding losses dominantly. I've done several=0Atransmit tests = and achieved 35 dB S/N in 4.5 mHz in a distance of 5 km,=0Ato my own VLF gr= abber.
=0ADuring the first times where the antenna was still shorter a = wrote a=0Ashort report with some pictures:=0A http://d= l.dropbox.com/u/19882028/VLF/VLF_5km_with_an_earth_antenna.pdf
=0ATe= sts with Michael Oexner (SWL, NDB hunter) in 49 km were positive too,=0Ain = DFCW-600, see the attached Mail from 2010. BTW this is a VERY good=0Ademons= tration of the positive effect of band limiting, clipping and=0Anoise blank= ing of the VLF signals processed in SpecLab. The picture=0Ashown my signal = with and without the SpecLabs noise reduction technics.=0AThis 49km distanc= e in 4.5 mHz  is the current record with an earth=0Aantenna. The trans= mit power was 200...250 watts if i remember correctly.
=0A
= =0AI will check if the antenna still exists and will refurbish it. Also i= =0Awill do new tests there. BTW i've done a recording on VLF using this=0Aa= ntenna in January, 29th 2011, if someone wants to play with it (1 GB):=0A = http://dl.dropbox.com/u/19882028/VLF/2901201= 1_12UTC_earth%20antenna_recording.WAV
=0A
=0AIn VK it s= eems you can easily arrange such an antenna, maybe even=0Aacross a stony hi= ll and grounded into the sea at one end. You just need=0Asome wire and a po= rtable PA :-) BTW this is the PA i was using:=0A http://www= .iup.uni-heidelberg.de/schaefer_vlf/12V_300W_VLF_PA.pdf
=0A =
=0A73, Stefan/DK7FC
=0A
=0A
=0A = =0A
= =0A
=0A
=0A
--1933340020-1596808829-1334162538=:37672--