Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dd01.r1000.mx.aol.com (Internet Inbound) with ESMTP id B230C38000083; Sun, 24 Jun 2012 10:04:01 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SinPM-0005oQ-1w for rs_out_1@blacksheep.org; Sun, 24 Jun 2012 15:03:20 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SinPL-0005oF-HE for rsgb_lf_group@blacksheep.org; Sun, 24 Jun 2012 15:03:19 +0100 Received: from elasmtp-kukur.atl.sa.earthlink.net ([209.86.89.65]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1SinPD-0001xF-Eb for rsgb_lf_group@blacksheep.org; Sun, 24 Jun 2012 15:03:18 +0100 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=V3WLVhl+P3CA21cxT3BDjnH2ov/236s/Q9x1CHT8c/8+5Xt1mgy5bZbs/YVl/DQO; h=Message-ID:Date:From:Reply-To:To:Subject:Mime-Version:Content-Type:Content-Transfer-Encoding:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [209.86.224.67] (helo=wamui-haziran.atl.sa.earthlink.net) by elasmtp-kukur.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1SinOr-0002ZA-7Y; Sun, 24 Jun 2012 10:02:49 -0400 Received: from 97.117.198.235 by webmail.c.earthlink.net with HTTP; Sun, 24 Jun 2012 10:02:48 -0400 Message-ID: <12295237.1340546569220.JavaMail.root@wamui-haziran.atl.sa.earthlink.net> Date: Sun, 24 Jun 2012 07:02:49 -0700 (GMT-07:00) From: Chris Trask To: rsgb_lf_group@blacksheep.org, rsgb_lf_group@blacksheep.org Mime-Version: 1.0 X-Mailer: EarthLink Zoo Mail 1.0 X-ELNK-Trace: b77fdb70683249914713efb067f9a722239a348a220c2609c111d02531985bea87e38bdced8a6cb1350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 209.86.224.67 X-Spam-Score: -0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: > >Thanks for sharing this interesting paper. Well, the circuit looks quite >complex but the image of the final construction looks compact. >Since we got access to 472 kHz a weeks ago, i need another receive >antenna now, since all my front ends are resonanted, i.e. mono band. So >the advantage of a single receive antenna becomes more and more >convincing to me. Of course it needs a high dynamic range without >distortion of the spectrum then.. > >A question: The DC supply voltage is connected to e.g. C16? > [...] Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [209.86.89.65 listed in list.dnswl.org] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: f62c7cf8eeb8e5a327b71719e9bffff1 Subject: Re: LF: Ferrite broadband (LF-MF) antenna? Content-Type: text/plain; charset=UTF-8 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-SCOLL-SCORE: 0:2:451184672:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d408d4fe71e50194d X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none > >Thanks for sharing this interesting paper. Well, the circuit looks quite >complex but the image of the final construction looks compact. >Since we got access to 472 kHz a weeks ago, i need another receive >antenna now, since all my front ends are resonanted, i.e. mono band. So >the advantage of a single receive antenna becomes more and more >convincing to me. Of course it needs a high dynamic range without >distortion of the spectrum then.. > >A question: The DC supply voltage is connected to e.g. C16? > It's connected by way of the output pin, so you send the DC supply right up the coax instead of having to run additional wires. You'll need a bias tee down at the receiver end, and I describe one at the end of this paper: http://www.home.earthlink.net/~christrask/Paper021.html > >What might be the lower cutoff frequency if values for the input LP and >HP filters are well choosen? It should be possible to extend the circuit >to the VLF range (?). > The amplifier itself without the input filter will go down to about 100-200kHz. To go lower than that you'll need to increase to capacitor values plus change the transformer core material to Fair-Rite 77 or something similar. Chris Trask N7ZWY / WDX3HLB Senior Member IEEE http://www.home.earthlink.net/~christrask/