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=-0.5 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO,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 u1QMpQeJ031928 for ; Fri, 26 Feb 2016 23:51:27 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1aZRAn-0002ut-9Y for rs_out_1@blacksheep.org; Fri, 26 Feb 2016 22:47:45 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1aZRAm-0002uk-Uv for rsgb_lf_group@blacksheep.org; Fri, 26 Feb 2016 22:47:44 +0000 Received: from brian.netcom.co.uk ([217.72.171.64]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1aZR91-0008Q0-UY for rsgb_lf_group@blacksheep.org; Fri, 26 Feb 2016 22:47:43 +0000 Received: from sb.abelian.org (i-194-106-52-83.freedom2surf.net [194.106.52.83]) by brian.netcom.co.uk (Postfix) with ESMTP id 991F1320088 for ; Fri, 26 Feb 2016 22:23:04 +0000 (GMT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by sb.abelian.org (Postfix) with ESMTP id 6867628A0220 for ; Fri, 26 Feb 2016 22:45:27 +0000 (UTC) Message-ID: <56D0D587.7080309@abelian.org> Date: Fri, 26 Feb 2016 22:45:27 +0000 From: Paul Nicholson User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 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> <56D0CC55.1060400@tele2.se> In-Reply-To: <56D0CC55.1060400@tele2.se> X-Scan-Signature: bb61bee384896e075004ae5ec954ddd2 Subject: Re: LF: MF: EbNaut Content-Type: text/plain; charset=ISO-8859-1; 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: 7023 I've done a lot of work over the years modelling air cored coils - and they're hard enough to get right. Throw in a core and it becomes a nightmare. So much depends on just how you wind and layer the turns, the type of wire, core properties. That's probably one challenge I'm not going to rise to. I admit - I am reduced to trial and error! Tomorrow I might try a 1:1:1 trifilar wind and use an L or pi match to raise the Z. Troubles lurk when I try to use more than about 1:2 turns ratio. If that fails I'll throw in the towel and change to single ended. As you can tell, it's the first time I've tried to make a broadband PA with a ferrite transformer. I naively thought it would be easy! I must say, I'm having fun with this - it's over 10 years since I last made a transmitter, and apart from these pesky toroidal transformers, everything seems quite easy to do at MF. -- Paul Nicholson --