Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dg02.r1000.mx.aol.com (Internet Inbound) with ESMTP id EF5323800009D; Fri, 6 Jul 2012 10:19:57 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Sn9NJ-00069W-Kb for rs_out_1@blacksheep.org; Fri, 06 Jul 2012 15:19:13 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Sn9NJ-00069N-7f for rsgb_lf_group@blacksheep.org; Fri, 06 Jul 2012 15:19:13 +0100 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1Sn9NG-0003uA-W2 for rsgb_lf_group@blacksheep.org; Fri, 06 Jul 2012 15:19:12 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id q66EJ8Hj031122 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Fri, 6 Jul 2012 16:19:09 +0200 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id q66EJ6qq024083 for ; Fri, 6 Jul 2012 16:19:07 +0200 Message-ID: <4FF6F362.3050305@iup.uni-heidelberg.de> Date: Fri, 06 Jul 2012 16:17:06 +0200 From: =?ISO-8859-15?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <7E7DFBB4D102A04DB5ADC88D66628A4A0FAB99CC@ICTS-S-MBX5.luna.kuleuven.be> <1SmrFA-199XcW0@fwd21.t-online.de> <4FF5EB68.9040507@iup.uni-heidelberg.de> <4FF61402.6000703@iup.uni-heidelberg.de> In-Reply-To: X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Roelof, Another interesting information which is new for me. Thank you. I think many of us have learned a bit from the topic. I thought about using super glue to fix the winding on the core. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [129.206.100.212 listed in list.dnswl.org] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: 739d4fb39bd02fc5a2de5437a39bb056 Subject: Re: LF: RE: Analog oscillators Content-Type: text/plain; charset=ISO-8859-15; format=flowed 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 x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:405433504:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d410a4ff6f40d1fd2 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi Roelof, Another interesting information which is new for me. Thank you. I think many of us have learned a bit from the topic. I thought about using super glue to fix the winding on the core. Or is this not to be recommended for some reason?. I will use a T50-6 then. This will take a few days until i have it on hand, unfortunately. 73, Stefan Am 06.07.2012 09:39, schrieb Roelof Bakker: > Hello Stefan, > > A FT-37-43 ferrite toroid is not suitable for a VFO as you found. > Powdered iron cores from Amidon are much better in this regard. > From the common available parts -6 material has the lowest temperature > coefficient, > -7 is slightly better: > > T-50-2: 95 ppm/C > T-50-6: 35 ppm/C > T-50-7: 30 ppm/C > > The temperature coefficient does not vary with the size of the toroid. > > There are tricks to achieve mechanical stable windings on a Toroid. > One is to wind it as tight as you can and than place the coil in > boiling water for 10 minutes. > This removes the mechanical stress and the winding settles down. > > 73, > Roelof, pa0rdt