X-GM-THRID: 1243751344316142051 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.70.87.11 with SMTP id k11cs229233wxb; Fri, 3 Aug 2007 02:35:14 -0700 (PDT) Received: by 10.82.189.6 with SMTP id m6mr3523379buf.1186133713480; Fri, 03 Aug 2007 02:35:13 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id k5si3991108nfh.2007.08.03.02.35.09; Fri, 03 Aug 2007 02:35:13 -0700 (PDT) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1IGtU4-0003UB-NM for rs_out_1@blacksheep.org; Fri, 03 Aug 2007 10:30:12 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1IGtU4-0003U2-47 for rsgb_lf_group@blacksheep.org; Fri, 03 Aug 2007 10:30:12 +0100 Received: from anchor-post-34.mail.demon.net ([194.217.242.92]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1IGtU3-0001GS-6V for rsgb_lf_group@blacksheep.org; Fri, 03 Aug 2007 10:30:12 +0100 Received: from dyn-62-56-125-161.dslaccess.co.uk ([62.56.125.161] helo=Tom) by anchor-post-34.mail.demon.net with esmtpa (AUTH telemetry) (Exim 4.42) id 1IGtU2-000OeX-E4; Fri, 03 Aug 2007 09:30:10 +0000 Message-ID: <008901c7d5b0$eea7c040$a17d383e@Tom> From: "Tom Boucher" To: Cc: "Finbar" References: <005001c7d3fe$e4786d80$6400a8c0@oem17oeylz9on8> <001901c7d42b$e6fbeaa0$86048351@w4o8m9> <00a001c7d43c$f4180690$0a7ee150@o> <1IGMYh-02648G0@fwd31.t-online.de> <003001c7d4d1$fcaf0390$db3a383e@Tom> <000101c7d5a4$5f527220$4e69e150@o> Date: Fri, 3 Aug 2007 10:30:20 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: Re: 500 / OLB test-sig... Content-Type: multipart/alternative; boundary="----=_NextPart_000_0086_01C7D5B9.4A99FBE0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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 Status: O X-Status: X-Keywords: X-UID: 753 This is a multi-part message in MIME format. ------=_NextPart_000_0086_01C7D5B9.4A99FBE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Rog (and others) - thank you for this. You may, or may not, be = interested in the matching arrangement for my antenna. The antenna is an extension of my 160 metre inverted 'L' which has an = 80' vertical section to a tree on a 20' bank - the effective height may = therefore not be as much as 80'. This antenna sits on 19 radials which = are 60 - 100' long and are either buried or lying on the ground, in = order to act as trip wires for my XYL when she trespasses on my antenna = area. An additional 358' has been added to this antenna to make the total = quarter wave length of 492'. This added wire zig-zags for 50' or so then = is largely in a straight line held up by 3 further tree halyards and = ends up about 30' above ground. This antenna with no matching showed a minimum VSWR at 506KHz of 2.5:1 = and impedance of 22 + j18. By empirical means (!) I established that a = parallel capacitance of some 6000 pF brought the SWR to a low figure = but, not unexpectedly, took the resonant frequency up to 521KHz; an = L-section using part of the antenna's self-inductance. To bring the = antenna back down to 502KHz, I added a small inductance between = capacitor/coax and the base of the antenna. The final values were 9 micro-Henrys (22 turns on 1'' dia) and 6,600pF = (3 x 2,200 pf 1000v polypropylene) giving 1.1:1 @ 503 KHz, 50 + j10. I was surprised at the high value of capacitance needed to resonate this = antenna and am not sure how you go about calculating the necessary = values as these were established by trial and error. Perhaps there is an = academic out there who can tell me! 73, Tom G3OLB ----- Original Message -----=20 From: GW3UEP=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Friday, August 03, 2007 8:55 AM Subject: LF: 500 / OLB test-sig... Tom, Hrd your test-loop ydy - steady S7 on meter - ur tidying up has wrkd! Ur closing the gap on Mike [S9/40mls via Preseli mountain] over the = ~90mls part sea-path bn us. Hope to improve ant nxt wk, jobs permitting. Rog. ----- Original Message -----=20 From: Gw3UEP=20 To: Tom Boucher=20 Sent: Monday, July 30, 2007 2:18 PM Subject: Re: Tom - what hve u done? Fantastic sig nw - on meter S5/6... ------=_NextPart_000_0086_01C7D5B9.4A99FBE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Rog (and others) - thank you for this. = You may, or=20 may not, be interested in the matching arrangement for my = antenna.
 
The antenna is an extension of my 160 = metre=20 inverted 'L' which has an 80' vertical section to a tree on a 20' bank - = the=20 effective height may therefore not be as much as 80'. This antenna sits = on 19=20 radials which are 60 - 100' long and are either buried or lying on the = ground,=20 in order to act as trip wires for my XYL when she trespasses on my = antenna=20 area.
 
An additional 358' has been added to = this antenna=20 to make the total quarter wave length of 492'. This added wire zig-zags = for 50'=20 or so then is largely in a straight line held up by 3 further tree = halyards and=20 ends up about 30' above ground.
 
This antenna with no matching showed a = minimum VSWR=20 at 506KHz of 2.5:1 and impedance of 22 + j18. By empirical means (!) I=20 established that a parallel capacitance of some 6000 pF brought the SWR = to a low=20 figure but, not unexpectedly, took the resonant frequency up to 521KHz; = an=20 L-section using part of the antenna's self-inductance. To bring the = antenna back=20 down to 502KHz, I added a small inductance between capacitor/coax and = the base=20 of the antenna.
 
The final values were 9 micro-Henrys = (22 turns on=20 1'' dia) and 6,600pF (3 x 2,200 pf 1000v polypropylene) giving 1.1:1 @ = 503 KHz,=20 50 + j10.
 
I was surprised at the high value of = capacitance=20 needed to resonate this antenna and am not sure how you go about = calculating the=20 necessary values as these were established by trial and error. Perhaps = there is=20 an academic out there who can tell me!
 
73, Tom
G3OLB
----- Original Message -----
From:=20 GW3UEP
Sent: Friday, August 03, 2007 = 8:55=20 AM
Subject: LF: 500 / OLB = test-sig...

Tom,
Hrd your test-loop ydy - steady S7 = on meter - ur=20 tidying up has wrkd!
Ur closing the gap on Mike = [S9/40mls via=20 Preseli mountain] over the ~90mls part sea-path bn us.
Hope to improve ant nxt wk, jobs=20 permitting.
Rog.
----- Original Message -----
From:=20 Gw3UEP
Sent: Monday, July 30, 2007 = 2:18 PM
Subject: Re:
 
Tom - what hve u done?  = Fantastic sig nw -=20 on meter S5/6...
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