Return-Path: Received: (qmail 51048 invoked from network); 17 Feb 2005 11:41:31 -0000 Received: from unknown (HELO ptb-spamcore02.plus.net) (192.168.71.3) by ptb-mailstore02.plus.net with SMTP; 17 Feb 2005 11:41:31 -0000 Received: from mailnull by ptb-spamcore02.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1D1k2K-000HnQ-Ji for dave@picks.force9.co.uk; Thu, 17 Feb 2005 11:41:42 +0000 Received: from [192.168.67.2] (helo=ptb-mxcore02.plus.net) by ptb-spamcore02.plus.net with esmtp (Exim 4.32; FreeBSD) id 1D1k2D-000Hke-SH for dave@picks.force9.co.uk; Thu, 17 Feb 2005 11:41:30 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1D1k1j-000K27-SW for dave@picks.force9.co.uk; Thu, 17 Feb 2005 11:40:59 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1D1k0e-0005VW-IU for rs_out_1@blacksheep.org; Thu, 17 Feb 2005 11:39:52 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1D1k0e-0005VL-6m for rsgb_lf_group@blacksheep.org; Thu, 17 Feb 2005 11:39:52 +0000 Received: from mailfe04.swip.net ([212.247.154.97] helo=swip.net) by relay.thorcom.net with esmtp (Exim 4.43) id 1D1k0a-0002ne-S6 for rsgb_lf_group@blacksheep.org; Thu, 17 Feb 2005 11:39:52 +0000 X-T2-Posting-ID: 7tTLvD67BptoA2C1rjPWBw== Received: from [213.101.38.160] ([213.101.38.160] verified) by mailfe04.swip.net (CommuniGate Pro SMTP 4.2.9) with ESMTP id 300405858 for rsgb_lf_group@blacksheep.org; Thu, 17 Feb 2005 12:39:40 +0100 Received: from 127.0.0.1 (AVG SMTP 7.0.300 [265.8.8]); Thu, 17 Feb 2005 11:40:19 -0100 Message-ID: <421490B1.1080704@tele2.se> Date: Thu, 17 Feb 2005 11:40:17 -0100 From: Johan Bodin User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206) X-Accept-Language: sv, en-us, en To: rsgb_lf_group@blacksheep.org References: In-Reply-To: Mime-Version: 1.0 X-SPF-Result: relay.thorcom.net: 212.247.154.97 is neither permitted nor denied by domain of tele2.se X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=failed,none Subject: Re: LF: RE: Matching Ropex Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com 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-Spam-Filtered: by PlusNet SpamCORE (v3.00) Dave Pick wrote: > I put a pi network (LPF) in between and it worked. Yes, that's the "impedance inversion" Markus DF6NM wrote about on the topic of "Wilkinson Combiner" recently. A Pi filter with all X = Zo behaves like a lumped circuit version of a quarter wave transmission line. For 50 ohms and 136.75 kHz that is: C1 = 23.3 nF across, L = 58.2 uH along, C2 = 23.3 nF across Open load => L and C2 in series resonance => input looks shorted Load = 50 ohms => input = 50 ohms Shorted load => L and C1 in parallel resonance => input looks open 73 Johan SM6LKM -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.8.8 - Release Date: 2005-02-14