Return-Path: Received: from mtain-dk07.r1000.mx.aol.com (mtain-dk07.r1000.mx.aol.com [172.29.180.11]) by air-md07.mail.aol.com (v129.4) with ESMTP id MAILINMD072-8b8d4d35e5c5f6; Tue, 18 Jan 2011 14:11:01 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk07.r1000.mx.aol.com (Internet Inbound) with ESMTP id 95055380000ED; Tue, 18 Jan 2011 14:10:59 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PfGwQ-0004Fp-Nv for rs_out_1@blacksheep.org; Tue, 18 Jan 2011 19:10:06 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PfGwQ-0004Fg-9o for rsgb_lf_group@blacksheep.org; Tue, 18 Jan 2011 19:10:06 +0000 Received: from cavuit02.kulnet.kuleuven.be ([134.58.240.44]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PfGwN-0005Xz-RM for rsgb_lf_group@blacksheep.org; Tue, 18 Jan 2011 19:10:06 +0000 Received: from smtps02.kuleuven.be (smtpshost02.kulnet.kuleuven.be [134.58.240.75]) by cavuit02.kulnet.kuleuven.be (Postfix) with ESMTP id A556275A1BC for ; Tue, 18 Jan 2011 20:09:55 +0100 (CET) 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 B7CE6F3862 for ; Tue, 18 Jan 2011 20:09:55 +0100 (CET) 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; Tue, 18 Jan 2011 20:09:55 +0100 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" Date: Tue, 18 Jan 2011 20:09:55 +0100 Thread-Topic: LF: Re: Separate Receiving Antenna? Thread-Index: Acu3P23t4j06Fx8qQyy63qGbUf2lpgAAi2jh Message-ID: References: <4D3454EA.9070003@iup.uni-heidelberg.de> <201101172134.30103.smtp01@email.it>, 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-KULeuven-Information: Katholieke Universiteit Leuven X-KULeuven-Scanned: Found to be clean X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: RE: LF: Re: Separate Receiving Antenna? Content-Type: multipart/alternative; boundary="_000_BF4A524700075746A6467658DFC7102C88715AEA8AICTSSEXC2CAlu_" 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, 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-sid: 3039ac1db40b4d35e5c30953 X-AOL-IP: 195.171.43.25 X-Mailer: Unknown (No Version) --_000_BF4A524700075746A6467658DFC7102C88715AEA8AICTSSEXC2CAlu_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello Tony, a quick and dirty simulation of the 125m tower shows a radiation resistanc= e of 1 Ohm and a capacitance of 2.5nF (what is a reactance of 460 Ohm at= 137kHz). So you would need only 0.55A antennacurrent to get 1W ERP, resulting in a= antenna voltage of less than 300V. If the choke has a reasonable Q you coult place a parallel capacitor and= make the LC circuit resonant at 137kHz. Cheap polyprop film cap's should= do the job. 73, Rik ON7YD ________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.or= g] namens Anton B=E4rtschi [hb9asb@gmail.com] Verzonden: dinsdag 18 januari 2011 19:39 Aan: rsgb_lf_group@blacksheep.org Onderwerp: Re: LF: Re: Separate Receiving Antenna? Thanks Claudio the mast is grounded via a choke. Unfortunately the inductivity is to low for 13= 6kHz. So we have to change it. But we will be careful. 10kV is not for joking. 73 de Toni --_000_BF4A524700075746A6467658DFC7102C88715AEA8AICTSSEXC2CAlu_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hello Tony,
 
a quick and dirty simulation of the= 125m tower shows a radiation resistance of 1 Ohm and a capacitance of 2.5= nF (what is a reactance of 460 Ohm at 137kHz).
So you would need only 0.55A antenna= current to get 1W ERP, resulting in a antenna voltage of less than 300V.
 
If the choke has a reasonable Q you coult place a parallel capacitor= and make the LC circuit resonant at 137kHz. Cheap polyprop film= cap's should do the job.
 
73, Rik  ON7YD
 
Van: owner-rsgb_= lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens Anton= B=E4rtschi [hb9asb@gmail.com]
Verzonden: dinsdag 18 januari 2011 19:39
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: Re: Separate Receiving Antenna?

Thanks Claudio
the mast is grounded via a choke. Unfortunately the inductivity is to low for 136kHz. So we have= to change it.
But we will be careful. 10kV is not for joking.
73 de Toni


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