Return-Path: <owner-rsgb_lf_group@blacksheep.org> Received: from rly-mg10.mx.aol.com (rly-mg10.mail.aol.com [172.20.83.116]) by air-mg03.mail.aol.com (v121.4) with ESMTP id MAILINMG034-a3d479602ccd; Tue, 22 Jan 2008 09:51:01 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mg10.mx.aol.com (v121.4) with ESMTP id MAILRELAYINMG107-a3d479602ccd; Tue, 22 Jan 2008 09:50:54 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1JHKRs-00060n-OS for rs_out_1@blacksheep.org; Tue, 22 Jan 2008 14:50:00 +0000 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1JHKRs-00060e-2h for rsgb_lf_group@blacksheep.org; Tue, 22 Jan 2008 14:50:00 +0000 Received: from mserv4.leeds.ac.uk ([129.11.76.223]) by relay2.thorcom.net with esmtp (Exim 4.63) (envelope-from <C.Trayner@Leeds.ac.uk>) id 1JHKRo-0005gq-2u for rsgb_lf_group@blacksheep.org; Tue, 22 Jan 2008 14:49:59 +0000 Received: from dexbr2.ds.leeds.ac.uk (dexbr2.leeds.ac.uk [129.11.76.20]) by mserv4.leeds.ac.uk (8.14.1/8.14.1) with ESMTP id m0MEnO98009684 for <rsgb_lf_group@blacksheep.org>; Tue, 22 Jan 2008 14:49:49 GMT Received: from HERMES4.ds.leeds.ac.uk ([129.11.5.129]) by dexbr2.ds.leeds.ac.uk with Microsoft SMTPSVC(6.0.3790.1830); Tue, 22 Jan 2008 14:49:46 +0000 X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Date: Tue, 22 Jan 2008 14:49:47 -0000 Message-ID: <731EB49F88B309428FFDDD2423F810E41A8B04@HERMES4.ds.leeds.ac.uk> X-MS-Has-Attach: X-MS-TNEF-Correlator: <731EB49F88B309428FFDDD2423F810E41A8B04@HERMES4.ds.leeds.ac.uk> Thread-Topic: LF: Fenceline longwire Thread-Index: AchdAoXPAJynLS/QSBKPWg/JLOwPUwAAT0+B References: <000501c85c3d$4fa2f820$0b01a8c0@weazle> <20080122135712.5D7C8F3862@smtps02.kuleuven.be> <005e01c85d01$81cff860$0900a8c0@Lark> From: "Chris Trayner" <C.Trayner@Leeds.ac.uk> To: <rsgb_lf_group@blacksheep.org> X-OriginalArrivalTime: 22 Jan 2008 14:49:46.0758 (UTC) FILETIME=[08204A60:01C85D06] X-Spam-Score: 0.1 (/) X-Spam-Report: autolearn=disabled,AWL=0.146 Content-Type: multipart/mixed; boundary="----_=_NextPart_001_01C85D06.0855FB8C" Subject: RE: LF: Fenceline longwire X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none 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-IP: 193.82.116.20 X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_helo : n X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_822_from : + X-Mailer: Unknown (No Version) ------_=_NextPart_001_01C85D06.0855FB8C Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable > Hi Rik isn't it more likely to be the case that these low antennas are muc= h more dependent on ground conditions, which are not modelled very well=20 Highly likely! This is one of the things that has become painfully obvious t= o those of us interested in cave radio. To add to the problems, there will be rock at some depth under the ground. T= his depth can vary enormously: soil over limestone is probably a metre or le= ss deep (very much a guess); in parts of southern England, on London Clay, h= ard rock can be tens or even a hundred metres down. Nor is there any reason=20= to suppose that the soil/rock boundary is either level or smooth.=20 The conductivities of soil and rock presumably matter, and may vary from pla= ce to place. They will certainly vary with the recent rainfall. So you may be dealing with a two-layer problem with a top layer of unknown a= nd possibly varying thickness, and two layers of unknown and varying conduct= ivity. Apart from that, modelling it is child's play! 73, Chris Trayner, G4OKW ----------------------------- Dr Chris Trayner School of Electronic & Electrical Engineering, The University of Leeds, Leeds LS2 9JT, United Kingdom Tel: +44 113 34 32053 Fax: +44 113 34 32032 ------_=_NextPart_001_01C85D06.0855FB8C Content-Type: application/ms-tnef; name="winmail.dat" Content-Transfer-Encoding: base64 eJ8+IjAOAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEIgAcAGAAAAElQTS5N aWNyb3NvZnQgTWFpbC5Ob3RlADEIAQ2ABAACAAAAAgACAAEEgAEAGwAAAFJFOiBMRjogRmVu Y2VsaW5lIGxvbmd3aXJlAO0IAQWAAwAOAAAA2AcBABYADgAxAC8AAgBmAQEggAMADgAAANgH AQAWAA4AMQAvAAIAZgEBCYABACEAAAA1RDI4MUExQjNFNjdCMTQ3OUVEM0UzNjdEQjRCNDM5 QQBCBwEDkAYAtAsAADkAAAADACYAAAAAAAMANgAAAAAAQAA5AIz7VQgGXcgBHgA9AAEAAAAF AAAAUkU6IAAAAAACAUcAAQAAADoAAABjPXVzO2E9IDtwPVVuaXZlcnNpdHkgb2YgTGU7bD1I RVJNRVM0LTA4MDEyMjE0NDk0N1otMjExOTMAAAAeAEkAAQAAABsAAABSZTogTEY6IEZlbmNl bGluZSBsb25nd2lyZQAAQABOAAA+Yn0BXcgBHgBaAAEAAAAjAAAAb3duZXItcnNnYl9sZl9n cm91cEBibGFja3NoZWVwLm9yZwAAAgFbAAEAAABjAAAAAAAAAIErH6S+oxAZnW4A3QEPVAIA AAAAb3duZXItcnNnYl9sZl9ncm91cEBibGFja3NoZWVwLm9yZwBTTVRQAG93bmVyLXJzZ2Jf bGZfZ3JvdXBAYmxhY2tzaGVlcC5vcmcAAAIBXAABAAAAKAAAAFNNVFA6T1dORVItUlNHQl9M Rl9HUk9VUEBCTEFDS1NIRUVQLk9SRwAeAF0AAQAAAAsAAABBbGFuIE1lbGlhAAACAV4AAQAA AEIAAAAAAAAAgSsfpL6jEBmdbgDdAQ9UAgAAAABBbGFuIE1lbGlhAFNNVFAAYWxhbi5tZWxp YUBidGludGVybmV0LmNvbQAAAAIBXwABAAAAHwAAAFNNVFA6QUxBTi5NRUxJQUBCVElOVEVS TkVULkNPTQAAHgBmAAEAAAAFAAAAU01UUAAAAAAeAGcAAQAAACMAAABvd25lci1yc2diX2xm X2dyb3VwQGJsYWNrc2hlZXAub3JnAAAeAGgAAQAAAAUAAABTTVRQAAAAAB4AaQABAAAAGgAA AGFsYW4ubWVsaWFAYnRpbnRlcm5ldC5jb20AAAAeAHAAAQAAABcAAABMRjogRmVuY2VsaW5l IGxvbmd3aXJlAAACAXEAAQAAABsAAAAByF0Chc8AnKctL9BIEo9aD8ks7A9TAABPT4EAHgB0 AAEAAAAdAAAAcnNnYl9sZl9ncm91cEBibGFja3NoZWVwLm9yZwAAAAAeABoMAQAAAA4AAABD aHJpcyBUcmF5bmVyAAAAHgAdDgEAAAAXAAAATEY6IEZlbmNlbGluZSBsb25nd2lyZQAAAgEJ EAEAAAAyBAAALgQAADgGAABMWkZ1678V2AMACgByY3BnMTI14jIDQ3RleAVBAQMB9/8KgAKk A+QHEwKAD/MAUARWPwhVB7IRJQ5RAwECAGNo4QrAc2V0MgYABsMRJfYzBEYTtzASLBEzCO8J 97Y7GB8OMDURIgxgYwBQ8wsJAWQzNhZQC6YK4wqAED4gSGkH8GlrIOkEAG4nBUBpBUAEYBgg BCBsHbBlbHkgdEhvIGIeoHRoHqBj9mEUEB+BYQVAH5Ef8Rew5wfgAHAOsG5uH+AhAB6Rum0a 0Ggc9B5zAQBwCfDrAQACMCACICAJwAhgIxArH8ACIGQeQGkCIHMsKCB3aA3gaCGTbm+THlIB AGxsCYAgdgSQPR8QdyXhHOUm6h1wZ2jjHwEexCEgVCTgBCApEXMCIB6gb2Yfgx+QC4BnfwQg ICMT4AQgH2AFoAeAIDMKsAuAZnUl8B8Qb2K6diRwdSpxH0AfkG8f8d8psSyBC4AOsBggcw6w I/BHC4AfwSZAIHJhJEBv+i4m6lQfQC7gI/Assytx8wNgAmBlbSShH5EekQPwtyaxH2EDYGMd wCBBcytSfyLRH5AtYCMRBcAfkiOkLu8o5DMkH9ADoHYKwB8QCfBvBbAEYCyAHwA6MsEDEW// JkEesQeBHzApgSkRMNIBoP0fAWEeYBQgHpEFsSYABBFzAQAi4CAoJkMh4jiRZ7MKUAQQKTsu QgqxdClR2ynAMtB1MXIDoEUqUAtgtyMQJLAjcUwkISNxQwtg/nkksBPhI/AyUzVSH2IJ8Lsp UQXAZSZAA6A4oGgj0a8YITi0NNEg4G40gE4Fsf8pETF0AHAfEBggH+AjcR8xcHN1cHAtAiAm NpMv3zJTBuAj0TWiKRFlHkAxgW85QSZANtEFwHMEYCWAaP80gC87H6IkIRrQJGAsUCRgfweR O9MDETzRMkQw0AeQdf8AwDhiAMACQASQJLBJggDA3x8QNZMDUiuAC2BjH3EfQPtMYzSCZSZx MeJMkAAgC3H/HwE1kwPwM1EfkhggTJAjQVcu0CuxB0BsLytTH0B5/whgS3MfYQEAB0AqQU7k OKDwdHdvLT3REoEw1VKXzm850FNULUJuayVwQTD/SXNDUQCQOGI1klJiKiEycP8pgAQQSyRT EVTUO7NVelbG9UgZeTSAQTtyTAQgIiSwPyW0UmIeQSkRE9ADEGQnizfxPdEhJuo3Mywc9KxD aAUQBCBULtB5KYBBSxFHNE9LVybvCu4tYc9iiRz0RAXAX2tQ5e8T0EawNtEpwEUmAEhgA2Dx AwBjICZl5Q3gB0A8gr8LgAngBRAqUF71R9JVAwCvJkEAkFrwKaJMCeBkJKAXHPRpsz1AUxRA OUpUtySwaNEuEksqQT2AbS+VAx7wNoArNDQgMTGoMyAzbRAzAdA1FTBxHQNGYXhs3m2gYKp9 AXBwAAAeADUQAQAAAEAAAAA8NzMxRUI0OUY4OEIzMDk0MjhGRkRERDI0MjNGODEwRTQxQThC MDRASEVSTUVTNC5kcy5sZWVkcy5hYy51az4AHgA5EAEAAAB+AAAAPDAwMDUwMWM4NWMzZCQ0 ZmEyZjgyMCQwYjAxYThjMEB3ZWF6bGU+IDwyMDA4MDEyMjEzNTcxMi41RDdDOEYzODYyQHNt dHBzMDIua3VsZXV2ZW4uYmU+IDwwMDVlMDFjODVkMDEkODFjZmY4NjAkMDkwMGE4YzBATGFy az4AAAAeAEcQAQAAAA8AAABtZXNzYWdlL3JmYzgyMgAACwDyEAEAAAAfAPMQAQAAAEYAAABS AEUAJQAzAEEAIABMAEYAJQAzAEEAIABGAGUAbgBjAGUAbABpAG4AZQAgAGwAbwBuAGcAdwBp AHIAZQAuAEUATQBMAAAAAAALAPYQAAAAAEAABzBG/A3DA13IAUAACDBi52EIBl3IAQMA3j+v bwAAAwDxPwkAAAAeAPg/AQAAAA4AAABDaHJpcyBUcmF5bmVyAAAAAgH5PwEAAABoAAAAAAAA ANynQMjAQhAatLkIACsv4YIBAAAAAAAAAC9PPVVOSVZFUlNJVFkgT0YgTEVFRFMvT1U9RklS U1QgQURNSU5JU1RSQVRJVkUgR1JPVVAvQ049UkVDSVBJRU5UUy9DTj1FRU5DVAAeAPo/AQAA ABUAAABTeXN0ZW0gQWRtaW5pc3RyYXRvcgAAAAACAfs/AQAAAB4AAAAAAAAA3KdAyMBCEBq0 uQgAKy/hggEAAAAAAAAALgAAAAMA/T/kBAAAAwAZQAAAAAADABpAAAAAAAMAHUAAAAAAAwAe QAAAAAAeADBAAQAAAAYAAABFRU5DVAAAAB4AMUABAAAABgAAAEVFTkNUAAAAHgAyQAEAAAAj AAAAb3duZXItcnNnYl9sZl9ncm91cEBibGFja3NoZWVwLm9yZwAAHgAzQAEAAAAaAAAAYWxh bi5tZWxpYUBidGludGVybmV0LmNvbQAAAB4AOEABAAAABgAAAEVFTkNUAAAAHgA5QAEAAAAC AAAALgAAAAMAdkD/////CwApAAAAAAALACMAAAAAAAMABhAdJoaxAwAHENEDAAADABAQAQAA AAMAERAAAAAAHgAIEAEAAABlAAAASElSSUtJU05USVRNT1JFTElLRUxZVE9CRVRIRUNBU0VU SEFUVEhFU0VMT1dBTlRFTk5BU0FSRU1VQ0hNT1JFREVQRU5ERU5UT05HUk9VTkRDT05ESVRJ T05TLFdISUNIQVJFTgAAAAACAX8AAQAAAEAAAAA8NzMxRUI0OUY4OEIzMDk0MjhGRkRERDI0 MjNGODEwRTQxQThCMDRASEVSTUVTNC5kcy5sZWVkcy5hYy51az4Azw0= ------_=_NextPart_001_01C85D06.0855FB8C--