Return-Path: Received: from mtain-mg07.r1000.mx.aol.com (mtain-mg07.r1000.mx.aol.com [172.29.96.207]) by air-mc07.mail.aol.com (v128.1) with ESMTP id MAILINMC072-a97c4bb10dfe33c; Mon, 29 Mar 2010 16:30:54 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mg07.r1000.mx.aol.com (Internet Inbound) with ESMTP id 0FDBC38000126; Mon, 29 Mar 2010 16:30:50 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NwLaC-00011D-Et for rs_out_1@blacksheep.org; Mon, 29 Mar 2010 21:29:12 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NwLaC-000114-07 for rsgb_lf_group@blacksheep.org; Mon, 29 Mar 2010 21:29:12 +0100 Received: from blu0-omc1-s12.blu0.hotmail.com ([65.55.116.23]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NwLa8-00021V-QQ for rsgb_lf_group@blacksheep.org; Mon, 29 Mar 2010 21:29:11 +0100 Received: from BLU146-W8 ([65.55.116.7]) by blu0-omc1-s12.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959); Mon, 29 Mar 2010 13:29:02 -0700 Message-ID: X-Originating-IP: [148.233.167.66] From: Laurence KL1X To: Date: Mon, 29 Mar 2010 12:29:02 -0800 Importance: Normal In-Reply-To: <38A51B74B884D74083D7950AD0DD85E82A1B93@File-Server-HST.hst.e-technik.tu-darmstadt.de> References: <2a2c8.24f60f40.38d54e4e@aol.com> <38A51B74B884D74083D7950AD0DD85E82A1B81@File-Server-HST.hst.e-technik.tu-darmstadt.de> <4BA5CFAA.2030007@freenet.de> <56800827A5644E1BB3F320CB51E2300E@Black> <26E279AD762E44FB937A8A7DF8F934BC@Black> <8C7F2923D86B4517B1C156BA499E96E4@Black> <29746320.1346347.1269244849281.JavaMail.fmail@mwmweb078> <4BA7361F.1030702@abelian.org> <4BA7A586.8080307@abelian.org> <38A51B74B884D74083D7950AD0DD85E82A1B87@File-Server-HST.hst.e-technik.tu-darmstadt.de> <0A742B5B9F6A4E84A802D1F98B670E79@JimPC> <20100323130953.2BEFC31E702@smtps01.kuleuven.be> <38A51B74B884D74083D7950AD0DD85E82A1B91@File-Server-HST.hst.e-technik.tu-darmstadt.de> ,<38A51B74B884D74083D7950AD0DD85E82A1B93@File-Server-HST.hst.e-technik.tu-darmstadt.de> MIME-Version: 1.0 X-OriginalArrivalTime: 29 Mar 2010 20:29:02.0471 (UTC) FILETIME=[784E5970:01CACF7E] X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Content-Type: multipart/alternative; boundary="_fe26c5e5-d389-4bc3-813e-008b5a32820f_" Subject: RE: AW: AW: LF: Re: Mini-Whip X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=FORGED_HOTMAIL_RCVD,HTML_20_30, 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 x-aol-global-disposition: G x-aol-sid: 3039ac1d60cf4bb10dfa43fe X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --_fe26c5e5-d389-4bc3-813e-008b5a32820f_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Optimum for mine for 10KHz and above is the famed 30cm =20 Laurence KL 1 X presently XE =20 Date: Wed, 24 Mar 2010 22:56:23 +0100 From: schaefer@hst.tu-darmstadt.de To: rsgb_lf_group@blacksheep.org Subject: AW: AW: LF: Re: Mini-Whip Hi Roelof, VLF,=20 =20 Yes, we (and others) arrived there on 137kHz and above. But it is so hard= to belive that this is optimal even in the 33km band. Maybe the optimum= C is not a function of the frequency, if discussing an optimal SNR.=20 But you know i am rather a practical instead of a theoretical OM ;-) There= fore i asked if someone has checked this before on VLF. I also know the eq= uivalent circuit of that probe and the FET input, out of Rs and Cs but any= way ;-) With a stronger input signal and same SNR there could be a benefit to unse= nsitive receivers as well (as you mentioned) as long as the input stage is= not overdriven... =20 Paul, have you a website where your RX equipment is shown? The antenna and= it's environment, cables and so on? Maybe the preamt with the LT1028 and= so on? =20 73, Stefan Von: owner-rsgb_lf_group@blacksheep.org im Auftrag von Roelof Bakker Gesendet: Mi 24.03.2010 22:40 An: rsgb_lf_group@blacksheep.org Betreff: Re: AW: LF: Re: Mini-Whip Hello Stefan, Just like you have reported some time ago, I have done tests to establish= =20 the best SNR for a whip antenna at LF in regard to the minimum length. I= =20 arrived at the same length as you did at 137 kHz: 30 cm. A longer antenna= =20 did improve the signal strength, but not the SNR. The capacitive probe is= =20 equivalent to a 30 cm whip. I can't see a reason why the SNR should change with frequency, but I will= =20 test it nevertheless. 73, Roelof, pa0rdt =20 _________________________________________________________________ Hotmail: Trusted email with powerful SPAM protection. http://clk.atdmt.com/GBL/go/210850553/direct/01/=3D --_fe26c5e5-d389-4bc3-813e-008b5a32820f_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Optimum for mine for 10KHz and above is the famed 30cm
 
Laurence KL 1 X
presently  XE
 
Date: Wed, 24 Mar 2010 22:56:23 +0100
From: schaefer@hst.tu-darmstadt.d= e
To: rsgb_lf_group@blacksheep.org
Subject: AW: AW: LF: Re: Mini-Whi= p

Hi Roelof, VLF,=
 
Yes, we (and others) arrived th= ere on 137kHz and above. But it is so hard to belive that this is optimal= even in the 33km band. Maybe the optimum C is not a function of the frequ= ency, if discussing an optimal SNR.
But you know i am rather a prac= tical instead of a theoretical OM ;-) Therefore i asked if someone has che= cked this before on VLF. I also know the equivalent circuit of that probe= and the FET input, out of Rs and Cs but anyway ;-)
With a stronger input signal an= d same SNR there could be a benefit to unsensitive receivers as well (as= you mentioned) as long as the input stage is not overdriven...
 
Paul, have you a website where= your RX equipment is shown? The antenna and it's environment, cables and= so on? Maybe the preamt with the LT1028 and so on?
 
73, Stefan

Von: owner-rsgb_lf_group@blacksheep.or= g im Auftrag von Roelof Bakker
Gesendet: Mi 24.03.2010 22:40
= An: rsgb_lf_group@blacksheep.org
Betreff: Re: AW: LF: Re:= Mini-Whip

Hello Stefan,

Just like you have reported some time= ago, I have done tests to establish 
the best SNR for a whip ante= nna at LF in regard to the minimum length. I 
arrived at the same= length as you did at 137 kHz: 30 cm. A longer antenna 
did improv= e the signal strength, but not the SNR. The capacitive probe is 
e= quivalent to a 30 cm whip.

I can't see a reason why the SNR should= change with frequency, but I will 
test it nevertheless.

7= 3,
Roelof, pa0rdt



=
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