Return-Path: Received: from rly-di02.mx.aol.com (rly-di02.mx.aol.com [172.29.64.6]) by air-di01.mail.aol.com (v126.13) with ESMTP id MAILINDI012-eab74b16aa138d; Wed, 02 Dec 2009 12:55:31 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-di02.mx.aol.com (Internet Inbound) with ESMTP id E45C338003995; Wed, 2 Dec 2009 12:55:29 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NFtOv-0006P8-CD for rs_out_1@blacksheep.org; Wed, 02 Dec 2009 17:54:05 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NFtOv-0006Oz-1C for rsgb_lf_group@blacksheep.org; Wed, 02 Dec 2009 17:54:05 +0000 Received: from smtp-vbr7.xs4all.nl ([194.109.24.27]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NFtOt-0007hn-CE for rsgb_lf_group@blacksheep.org; Wed, 02 Dec 2009 17:54:05 +0000 Received: from pc1 (ndb.demon.nl [82.161.81.65]) by smtp-vbr7.xs4all.nl (8.13.8/8.13.8) with ESMTP id nB2HrlS9076334 for ; Wed, 2 Dec 2009 18:54:00 +0100 (CET) (envelope-from roelof@ndb.demon.nl) Date: Wed, 02 Dec 2009 17:53:46 -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> <4B16987B.9000002@usa.net> Message-ID: In-Reply-To: <4B16987B.9000002@usa.net> User-Agent: Opera Mail/9.63 (Win32) X-Virus-Scanned: by XS4ALL Virus Scanner X-Karma: unknown: 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-global-disposition: G x-aol-sid: 3039ac1d40064b16aa112b88 X-AOL-IP: 172.29.64.6 X-Mailer: Unknown (No Version) Hello Alberto, I have used a large coffee tin (30 cm high and 27 cm diameter), for a passive electric field probe. The capacitance was way to high for active circuitry. Instead a rf transformer wound on a hefty high mu toroid was used to couple the antenna to the coaxial feedline. It worked, though the bandwidth was restricted to LF and MF. An other example is using a small diecast alluminium box (50 x 50 x 30 mm) with the buffer amplifier mounted inside. 73, Roelof, pa0rdt