X-GM-THRID: 1235289960733538477 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.35.12.7 with SMTP id p7cs62303pyi; Thu, 3 May 2007 14:23:47 -0700 (PDT) Received: by 10.66.222.9 with SMTP id u9mr2189712ugg.1178227427142; Thu, 03 May 2007 14:23:47 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id p32si3294533ugc.2007.05.03.14.23.44; Thu, 03 May 2007 14:23:47 -0700 (PDT) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1HjikK-00057D-Rx for rs_out_1@blacksheep.org; Thu, 03 May 2007 22:21:52 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1HjikK-000574-CC for rsgb_lf_group@blacksheep.org; Thu, 03 May 2007 22:21:52 +0100 Received: from fish2.hurontel.on.ca ([216.46.129.163]) by relay2.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1HjikI-0002dN-Qk for rsgb_lf_group@blacksheep.org; Thu, 03 May 2007 22:21:52 +0100 Received: from server (dial185-ripley2.hurontel.on.ca [216.46.149.185]) by fish2.hurontel.on.ca (Spam Firewall) with SMTP id 270C9302781 for ; Thu, 3 May 2007 17:21:41 -0400 (EDT) Message-ID: <009101c78dc0$c1836700$0b01a8c0@server> From: "J. B. Weazle McCreath" To: References: <004d01c78c3a$48757ec0$0b01a8c0@server> <003501c78c4d$0d68f060$0300a8c0@lark> <006a01c78d17$440b3d60$0b01a8c0@server> <8C95BC9DABC7512-1190-E1D2@FWM-M30.sysops.aol.com> Date: Thu, 3 May 2007 21:22:05 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2720.3000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: -0.3 (/) X-Spam-Report: autolearn=disabled,AWL=-0.329 Subject: Re: LF: Re: Passive high-pass filter circuits? Content-Type: text/plain; charset="iso-8859-1" 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 Status: O X-Status: X-Keywords: X-UID: 1694 Hi John, LFers, The source and load Z are both 600 ohms. I'm using a telephone "repeater coil" at the shack end of the line for isolation from local ground of the sound card's mic-in. The "antenna" is an untuned, equilateral triangle loop, apex up and measures 111 feet per side. It's matched to the line with a small line to voice coil transformer, (Hammond 119DA) which is good up to 20 kHz. Calculations showed a close match over the frequency range I'm interested in. I want to put the filter in the floating 600 ohm line to reduce the 60 Hz. mains buzz and its first few harmonics so that the signal going into the sound card is already "cleaned up" a bit. 73, J.B., VE3EAR - VE3WZL Solar and wind powered Lowfer " EAR" 188.830 EN93dr http://www.hurontel.on.ca/~weazle