Return-Path: Received: from rly-de05.mx.aol.com (rly-de05.mail.aol.com [172.19.170.141]) by air-de07.mail.aol.com (v126.13) with ESMTP id MAILINDE072-4db4b16a033145; Wed, 02 Dec 2009 12:13:32 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-de05.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDE058-4db4b16a033145; Wed, 02 Dec 2009 12:13:25 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NFska-0005bo-GM for rs_out_1@blacksheep.org; Wed, 02 Dec 2009 17:12:24 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NFska-0005bf-3m for rsgb_lf_group@blacksheep.org; Wed, 02 Dec 2009 17:12:24 +0000 Received: from smtp-vbr4.xs4all.nl ([194.109.24.24]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NFskY-0006TJ-AA for rsgb_lf_group@blacksheep.org; Wed, 02 Dec 2009 17:12:24 +0000 Received: from pc1 (ndb.demon.nl [82.161.81.65]) by smtp-vbr4.xs4all.nl (8.13.8/8.13.8) with ESMTP id nB2HCD6o071749 for ; Wed, 2 Dec 2009 18:12:22 +0100 (CET) (envelope-from roelof@ndb.demon.nl) Date: Wed, 02 Dec 2009 17:12:12 -0000 To: rsgb_lf_group@blacksheep.org From: "Roelof Bakker" MIME-Version: 1.0 References: <38A51B74B884D74083D7950AD0DD85E828AAF4@File-Server-HST.hst.e-technik.tu-darmstadt.de> Message-ID: In-Reply-To: <38A51B74B884D74083D7950AD0DD85E828AAF4@File-Server-HST.hst.e-technik.tu-darmstadt.de> User-Agent: Opera Mail/9.63 (Win32) X-Virus-Scanned: by XS4ALL Virus Scanner X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Results of optimising an active antenna Content-Type: text/plain; format=flowed; delsp=yes; charset=iso-8859-15 Content-Transfer-Encoding: 7bit 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-Mailer: Unknown (No Version) Hello Stefan, Thank you for your detailed description. I have carried out the same tests some five years ago and arrived also at a length of 30 cm. The wire can be replaced by a 30 x 40 mm piece of copper clad PCB for the same results. Using SMD parts, which have less capacitive coupling due to the small size, a further size reduction is possible. Your findings that raising the antenna higher than 4 m is correct as the signal to noise ratio will not improve, so nothing will be gained. However, this depends on the surroundings. At the border of a lake, I found an height of 2 m sufficient for weak signal work at LF. Best regards, Roelof Bakker, pa0rdt