Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk06.r1000.mx.aol.com (Internet Inbound) with ESMTP id E7D3038000097; Wed, 12 Oct 2011 03:32:06 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RDtHQ-0008Vq-A4 for rs_out_1@blacksheep.org; Wed, 12 Oct 2011 08:31:08 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RDtHP-0008Vh-Sj for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2011 08:31:07 +0100 Received: from rhcavuit01.kulnet.kuleuven.be ([134.58.240.129] helo=cavuit01.kulnet.kuleuven.be) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RDtHN-0003cu-RA for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2011 08:31:07 +0100 X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-KULeuven-Scanned: Found to be clean X-KULeuven-ID: 3C928138027.A4607 X-KULeuven-Information: Katholieke Universiteit Leuven Received: from smtps02.kuleuven.be (smtpshost02.kulnet.kuleuven.be [134.58.240.75]) by cavuit01.kulnet.kuleuven.be (Postfix) with ESMTP id 3C928138027 for ; Wed, 12 Oct 2011 09:30:59 +0200 (CEST) Received: from ICTS-S-HUB-N3.luna.kuleuven.be (icts-s-hub-n3.luna.kuleuven.be [10.112.9.13]) by smtps02.kuleuven.be (Postfix) with ESMTP id 142ACF3862 for ; Wed, 12 Oct 2011 09:30:59 +0200 (CEST) Received: from ICTS-S-EXC2-CA.luna.kuleuven.be ([10.112.11.13]) by ICTS-S-HUB-N3.luna.kuleuven.be ([10.112.9.13]) with mapi; Wed, 12 Oct 2011 09:30:59 +0200 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" Date: Wed, 12 Oct 2011 09:30:59 +0200 Thread-Topic: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. Thread-Index: AcyIaqOa2qLKqeu3TECB76oQ8muUsgAQarKb Message-ID: References: <4E91694C.8060900@orange.fr> <4E9169AD.8090609@wanadoo.fr> <4E918C0E.30401@freenet.de> <4E918FF1.1010407@iup.uni-heidelberg.de> <1318166502.15085.YahooMailNeo@web28106.mail.ukl.yahoo.com> <1849736542-1318171189-cardhu_decombobulator_blackberry.rim.net-208700020-@b1.c11.bise7.blackberry> <4E920BBA.9040200@iup.uni-heidelberg.de> <4E934A40.9040204@gmx.de> <006c01cc87ab$427234c0$4001a8c0@lark> <834DCCD1D3834F4CB4C171B7C30E85B4@AGB> <004801cc8809$63378d50$4001a8c0@lark> , In-Reply-To: Accept-Language: nl-NL, nl-BE Content-Language: nl-BE X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: nl-NL, nl-BE MIME-Version: 1.0 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: RE: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. Content-Type: multipart/alternative; boundary="_000_BF4A524700075746A6467658DFC7102CB0B27CF3E0ICTSSEXC2CAlu_" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,HTML_FONTCOLOR_BLUE, 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-SCORE: 0:2:395938816:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1db40a4e9542767668 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --_000_BF4A524700075746A6467658DFC7102CB0B27CF3E0ICTSSEXC2CAlu_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I'm puzzled by the 6pf/metre rule for monoploes. It seems the capacitance = of the monopole is much higher. Hi Joe, based on a resonance with 3mH @137.8kHz the antenna capacitance would be 44= 5pF. A rato of 5..6pF/m you should have more or less 75..90m of wire up in the a= ir (vertical and horizontal section). But the given value of 5..6pF/m is only valid for thin wire. If you use ver= y thick wire or maybe even a tower as part of the antenna the capacitance i= s larger. For a 1m diameter tower the capacitance can be as high as 25pF/m 73, Rik ON7YD - OR7T --_000_BF4A524700075746A6467658DFC7102CB0B27CF3E0ICTSSEXC2CAlu_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I'm puzzled by the 6pf/metre rule for monopl= oes.  It seems the capacitance of the monopole is much higher.<= /em>

 

Hi Joe,

 

based on a resonance with 3mH @137.8kHz t= he antenna capacitance would be 445pF.

A rato of 5..6pF/m you should have more o= r less 75..90m of wire up in the air (vertical and horizontal section).

But the given value of 5..6pF/m is only v= alid for thin wire. If you use very thick wire or maybe even a tower as par= t of the antenna the capacitance is larger. For a 1m diameter tower the cap= acitance can be as high as 25pF/m

 

73, Rik  ON7YD - OR7T

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