Return-Path: Received: (qmail 73472 invoked from network); 28 Mar 2005 17:26:11 -0000 Received: from unknown (HELO ptb-spamcore02.plus.net) (192.168.71.3) by ptb-mailstore04.plus.net with SMTP; 28 Mar 2005 17:26:11 -0000 Received: from mailnull by ptb-spamcore02.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1DFy6G-0002PN-8M for dave@picks.force9.co.uk; Mon, 28 Mar 2005 18:32:28 +0100 Received: from [192.168.67.2] (helo=ptb-mxcore02.plus.net) by ptb-spamcore02.plus.net with esmtp (Exim 4.32; FreeBSD) id 1DFy6F-0002PA-HF for dave@picks.force9.co.uk; Mon, 28 Mar 2005 18:32:27 +0100 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1DFy09-000Kzl-Gf for dave@picks.force9.co.uk; Mon, 28 Mar 2005 17:26:09 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1DFxzi-0002H3-Fx for rs_out_1@blacksheep.org; Mon, 28 Mar 2005 18:25:42 +0100 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1DFxzi-0002Gu-0Q for rsgb_lf_group@blacksheep.org; Mon, 28 Mar 2005 18:25:42 +0100 Received: from smtp813.mail.ukl.yahoo.com ([217.12.12.203]) by relay.thorcom.net with smtp (Exim 4.43) id 1DFxzf-0001EF-Ge for rsgb_lf_group@blacksheep.org; Mon, 28 Mar 2005 18:25:41 +0100 Received: from unknown (HELO Main) (Alan.Melia@213.122.120.253 with login) by smtp813.mail.ukl.yahoo.com with SMTP; 28 Mar 2005 17:25:33 -0000 Message-ID: <001901c533bb$2916fb00$6507a8c0@Main> From: "Alan Melia" To: rsgb_lf_group@blacksheep.org References: <001301c533a6$e3f37c60$2102000a@ibm> Date: Mon, 28 Mar 2005 18:21:28 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 X-SPF-Result: relay.thorcom.net: 217.12.12.203 is neither permitted nor denied by domain of btinternet.com X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=failed,none Subject: LF: Re: the use of Epcos cores on LF 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=1.1 required=5.0 tests=MAILTO_TO_SPAM_ADDR 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) Hi Dick the Epcos core data is on the web but the PDF file download doesnt work for me. See http://www.search.epcos.com/pls/prins/para_search.init?M_SPRACHID=2 I have a number of large epcos cores but have not tried to use them yet. As to the transformer loss....do you have enough turns ?? Do you have too many turns. I magine ther is no DC flowing through the winding. Have you tried stacking a couple of cores to increase the cross-section area??. Cheers de Alan G3NYK alan.melia (at) btinternet.com ----- Original Message ----- From: "Dick" To: Sent: 28 March 2005 16:00 Subject: LF: the use of Epcos cores on LF > A question, especially for our German members. > > Epcos makes (big) cores of so called N30 material. > I previously used an 58mm core to match 50 Ohm to 135Ohm, but it got > really hot at around 400-500Watt or so. > I wonder if this is normal or not (Ui=4300) > > These cores are relatively cheap, so I hoped it was a good solution for big > (output) transformers. > Now I am not to sure anymore........... > > Also interested to know if anyone has experience in using a low beverage, > let's say 400-500m long at 1m heigth as TX antenna. > Not earthed/resistor at the end, just a simple very long wire at 1m heigth. > > 73 > > Dick, pa4vhf > >