Return-Path: X-Spam-DCC: paranoid 1170; Body=3 Fuz1=3 Fuz2=3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, RATWARE_GECKO_BUILD,SPF_PASS autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u1QMChAs031880 for ; Fri, 26 Feb 2016 23:12:43 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1aZQZ2-0002WR-Mw for rs_out_1@blacksheep.org; Fri, 26 Feb 2016 22:08:44 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1aZQZ2-0002WH-Cp for rsgb_lf_group@blacksheep.org; Fri, 26 Feb 2016 22:08:44 +0000 Received: from mailfe02.swip.net ([212.247.154.33] helo=swip.net) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1aZQX3-0008Dy-GG for rsgb_lf_group@blacksheep.org; Fri, 26 Feb 2016 22:08:43 +0000 X-T2-Spam-Status: No, hits=0.8 required=5.0 tests=BAYES_50 Received: from [81.224.101.198] (account cxu-dcw-tyr@tele2.se HELO [192.168.1.3]) by mailfe02.swip.net (CommuniGate Pro SMTP 5.4.4) with ESMTPSA id 654046896 for rsgb_lf_group@blacksheep.org; Fri, 26 Feb 2016 23:06:09 +0100 To: rsgb_lf_group@blacksheep.org References: <56D08BEF.7070708@abelian.org> <8D33ED4DA8562EE-14E0-601004@webmail-vm018.sysops.aol.com> <56D0934B.1040700@abelian.org> <56D098D3.80501@abelian.org> <56D0B22B.2020107@abelian.org> <56D0B58A.80908@tiscali.co.uk> <56D0C373.1090004@abelian.org> From: Johan Bodin Message-ID: <56D0CC55.1060400@tele2.se> Date: Fri, 26 Feb 2016 23:06:13 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <56D0C373.1090004@abelian.org> X-HELO-Warning: Remote host 212.247.154.33 (mailfe02.swip.net) used invalid HELO/EHLO swip.net - verification failed X-Scan-Signature: c1f72e5acb1277e013f90c915ad7ad68 Subject: Re: LF: MF: EbNaut Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.11 Status: O X-Status: X-Keywords: X-UID: 7021 Been there.... Done that... Direct flux linkage between windings, capacitive coupling, magnetic coupling through the core, funny core behaviour at RF etc. etc. For a start, google bifilar trifilar transformer transmission line... My own limited experience tells me that broadband RF transformers is black art. Forget about science, just experiment in the dark until it works :-) If I had your knowledge of math and programming, I would build a transformer model in software and write a program, that includes a database of all known ferrite cores and Litz wire manufacturers, that takes the wanted performance and maximum price as input and suggest the best transformer compromise with performance curves as output. Am I asking too much? See it as a challenge! :-D Almost joking... 73 Johan SM6LKM Paul Nicholson wrote: > I find that to get the leakage inductance down low enough > the secondary has to be wound on top of the bifilar > primary. Is that normal? If I space the turns neatly > around the toroid, the leakage inductance is way too > high.