Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mh02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 8E20F3800009F; Wed, 12 Oct 2011 07:53:56 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RDxMv-0002F9-3M for rs_out_1@blacksheep.org; Wed, 12 Oct 2011 12:53:05 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RDxMu-0002F0-Js for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2011 12:53:04 +0100 Received: from rhcavuit02.kulnet.kuleuven.be ([134.58.240.130] helo=cavuit02.kulnet.kuleuven.be) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RDxMs-00061x-3T for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2011 12:53:04 +0100 X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-KULeuven-Scanned: Found to be clean X-KULeuven-ID: 9170312802A.A5433 X-KULeuven-Information: Katholieke Universiteit Leuven Received: from smtps02.kuleuven.be (smtpshost02.kulnet.kuleuven.be [134.58.240.75]) by cavuit02.kulnet.kuleuven.be (Postfix) with ESMTP id 9170312802A for ; Wed, 12 Oct 2011 13:52:47 +0200 (CEST) Received: from ICTS-S-HUB-N1.luna.kuleuven.be (icts-s-hub-n1.luna.kuleuven.be [10.112.9.11]) by smtps02.kuleuven.be (Postfix) with ESMTP id 6B219F3862 for ; Wed, 12 Oct 2011 13:52:47 +0200 (CEST) Received: from ICTS-S-EXC2-CA.luna.kuleuven.be ([10.112.11.13]) by ICTS-S-HUB-N1.luna.kuleuven.be ([10.112.9.11]) with mapi; Wed, 12 Oct 2011 13:52:47 +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 13:52:46 +0200 Thread-Topic: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. Thread-Index: AcyIyK+o5bMYxt9yQ4ue25sPEOwC7wAB3ysu 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> , ,<4E956953.3030207@iup.uni-heidelberg.de> In-Reply-To: <4E956953.3030207@iup.uni-heidelberg.de> 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_BF4A524700075746A6467658DFC7102CB0B27CF3E7ICTSSEXC2CAlu_" 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: 0:2:459446112:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d60d64e957fd35990 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --_000_BF4A524700075746A6467658DFC7102CB0B27CF3E7ICTSSEXC2CAlu_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello Stefan, the formula for the capacitance of a vertical monopole with a height H (m) = and a diameter d (m) is: C(pF) =3D 24*H/log(1.15*H/d) I got the formula from "Taschenbuch der Hochfrequenztechnik" by Meinke&Gund= lach (3de edition, 1968) Mit etwas Gl=FCck kannst du das Buch an der Uni auftreiben, es ist das lese= n wert. ISBN gab es dann noch nicht, aber Library of Congres Catalog Card Number is= t 67-29831. 73, Rik ON7YD - OR7T ________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org= ] namens Stefan Sch=E4fer [Stefan.Schaefer@iup.uni-heidelberg.de] Verzonden: woensdag 12 oktober 2011 12:17 Aan: rsgb_lf_group@blacksheep.org Onderwerp: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. Hello Rik, Interesting, haven't known that. What do you think applies for a 10mm diame= ter wire? 73, Stefan Am 12.10.2011 09:30, schrieb Rik Strobbe: 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_BF4A524700075746A6467658DFC7102CB0B27CF3E7ICTSSEXC2CAlu_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hello Stefan,
 
the formula for the capacitance of a = vertical monopole with a height H (m) and a diameter d (m) is:
 
C(pF) =3D 24*H/log(1.15*H/d)
 
I got the formula from &quo= t;Taschenbuch der Hochfrequenztechnik" by Meinke&Gundlach (3de edi= tion, 1968)
 
Mit etwas Gl=FCck kannst du das Buch = an der Uni auftreiben, es ist das lesen wert.
ISBN gab es dann noch nicht, aber Lib= rary of Congres Catalog Card Number ist 67-29831.
 
73, Rik  ON7YD - OR7T
 
 
=  
Van: owner-rsgb_l= f_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens Stefan S= ch=E4fer [Stefan.Schaefer@iup.uni-heidelberg.de]
Verzonden: woensdag 12 oktober 2011 12:17
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c.

Hello Rik,

Interesting, haven't known that. What do you think applies for a 10mm diame= ter wire?

73, Stefan

Am 12.10.2011 09:30, schrieb Rik Strobbe:

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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