Return-Path: Received: (qmail 23888 invoked from network); 27 Dec 2004 05:26:35 -0000 Received: from unknown (HELO ptb-spamcore02.plus.net) (192.168.71.3) by ptb-mailstore01.plus.net with SMTP; 27 Dec 2004 05:26:35 -0000 Received: from mailnull by ptb-spamcore02.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1CinMB-000PCF-0k for dave@picks.force9.co.uk; Mon, 27 Dec 2004 05:23:47 +0000 Received: from [192.168.67.1] (helo=ptb-mxcore01.plus.net) by ptb-spamcore02.plus.net with esmtp (Exim 4.32; FreeBSD) id 1CinMA-000PCC-Tk for dave@picks.force9.co.uk; Mon, 27 Dec 2004 05:23:46 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (Exim 4.30; FreeBSD) id 1CinOt-00058G-3v for dave@picks.force9.co.uk; Mon, 27 Dec 2004 05:26:35 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1CinOO-00069W-5a for rs_out_1@blacksheep.org; Mon, 27 Dec 2004 05:26:04 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1CinON-00069N-Ph for rsgb_lf_group@blacksheep.org; Mon, 27 Dec 2004 05:26:03 +0000 Received: from fmmailgate05.web.de ([217.72.192.243]) by relay.thorcom.net with esmtp (Exim 4.41) id 1CinOM-0005UU-1r for rsgb_lf_group@blacksheep.org; Mon, 27 Dec 2004 05:26:03 +0000 Received: by fmmailgate05.web.de (8.12.10/8.12.10/webde Linux 0.7) with SMTP id iBR5PtCK010974 for rsgb_lf_group@blacksheep.org; Mon, 27 Dec 2004 06:25:56 +0100 Received: from [217.248.191.233] by freemailng1802.web.de with HTTP; Sun, 26 Dec 2004 21:34:05 +0100 Date: Sun, 26 Dec 2004 21:34:05 +0100 Message-Id: <258675404@web.de> MIME-Version: 1.0 From: "Hans-Albrecht Haffa" To: rsgb_lf_group@blacksheep.org Organization: http://freemail.web.de/ X-SPF-Result: relay.thorcom.net: 217.72.192.243 is neither permitted nor denied by domain of web.de X-Spam-Score: 2.7 (++) X-Spam-Report: autolearn=no,DATE_IN_PAST_06_12=0.599,DRASTIC_REDUCED=1.998,RCVD_IN_SORBS=0.1 Subject: LF: RE: M0BMU mods for G0MRF 300 W Tx is this a gap? Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.6 required=5.0 tests=DATE_IN_PAST_06_12, DRASTIC_REDUCED 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) Hello Lowfers, yes it is a gap. A residuous gap of two core halves with lapped surfaces is still a gap. It will reduce relative permeability and remanent flux. It is better to use core halves with a bit greater gapmade of a layer of insulating tape (0,05 mm thickness ) on both sides of a core half. Lowering remanent flux from 180 mt (ungapped ring core) to about 30 mT gapped will rise magnetic swing in mMilli-Tesla. Thats what counts. If You take out the spacers of a deflection transformer, You get agood core for a forward converter SMPS or a 136 kHz PA. 55, Hans-Albrecht DK 8 ND rsgb_lf_group@blacksheep.org schrieb am 24.12.04 10:55:28: > > > ----- Original Message ----- > From: "james moritz" > To: > Sent: Thursday, December 23, 2004 11:31 AM > Subject: LF: RE: M0BMU mods for G0MRF 300 W Tx > > > Dear Gary, LF Group, > > You need one without an air gap - the air gap will drastically reduce the > winding inductance, unfortunately. > > Hi All > I have used these cores and noticed no difference between them and a > continuous type core. I put the two core halves together tightly and used > the same number of turns as used on the continuous core, maybe I was lucky. > What does Jim call a gap? If they are tight together is that considered a > gap? Must the core be totally continuous? > de Mal/G3KEV > > > > > > > > > > ________________________________________________________________ Verschicken Sie romantische, coole und witzige Bilder per SMS! Jetzt neu bei WEB.DE FreeMail: http://freemail.web.de/?mc=021193