Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 60C28380000AD; Fri, 16 Dec 2011 09:25:39 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RbYiN-0004RI-Kj for rs_out_1@blacksheep.org; Fri, 16 Dec 2011 14:24:47 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RbYiN-0004R9-96 for rsgb_lf_group@blacksheep.org; Fri, 16 Dec 2011 14:24:47 +0000 Received: from mail-iy0-f171.google.com ([209.85.210.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RbYiL-0001jz-1c for rsgb_lf_group@blacksheep.org; Fri, 16 Dec 2011 14:24:47 +0000 Received: by iagw33 with SMTP id w33so4319989iag.16 for ; Fri, 16 Dec 2011 06:24:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=ThfMoyHSkKFnOHVNJ7BnzLyrwqHTYiI/BumU3qLSP8A=; b=tdxyBxAgI+gCtubhtsJe3vwkT6A+y0/MDNGEyFk5OlW4h63qvqb0z/I+9JC86rJAtT EXBhWwPpRXae3EfYtpBNvvfq2BN95wI7pO6WSymdIqHLMPxTL2LjJYxFchAzcEe9/8q5 BgfvB+Ul/gHX2cSoewoW22CYbAAJiUPd4+drM= MIME-Version: 1.0 Received: by 10.50.207.40 with SMTP id lt8mr9032522igc.43.1324045478464; Fri, 16 Dec 2011 06:24:38 -0800 (PST) Received: by 10.231.66.5 with HTTP; Fri, 16 Dec 2011 06:24:38 -0800 (PST) In-Reply-To: <5189193.1324041277063.JavaMail.root@wamui-bucket.atl.sa.earthlink.net> References: <5189193.1324041277063.JavaMail.root@wamui-bucket.atl.sa.earthlink.net> Date: Fri, 16 Dec 2011 14:24:38 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: RE: Wellbrook Loop Content-Type: text/plain; charset=ISO-8859-1 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: 0:2:451466528:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m220.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1db4084eeb54e3565c X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This one from Chris has an input stage similar to the design I did those years ago, but with added feedback and more. The common base push-pull running open-loop, if memory serves, gave about 0.5 ohms input impedance running the devices at 100mA (on heat sinks !) Andy www.g4jnt.com . > > http://www.home.earthlink.net/~christrask/Paper009.html > > > Chris Trask > N7ZWY / WDX3HLB > Senior Member IEEE > http://www.home.earthlink.net/~christrask/ >