Return-Path: X-Spam-DCC: paranoid 1233; 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=-0.3 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_30_40,HTML_MESSAGE,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 u2AN3OZ6006386 for ; Fri, 11 Mar 2016 00:03:24 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ae9YZ-00076i-UM for rs_out_1@blacksheep.org; Thu, 10 Mar 2016 22:59:47 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ae9YZ-00076Z-LJ for rsgb_lf_group@blacksheep.org; Thu, 10 Mar 2016 22:59:47 +0000 Received: from mout01.posteo.de ([185.67.36.65]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.86) (envelope-from ) id 1ae9YY-00027B-2g for rsgb_lf_group@blacksheep.org; Thu, 10 Mar 2016 22:59:46 +0000 Received: from dovecot03.posteo.de (dovecot03.posteo.de [172.16.0.13]) by mout01.posteo.de (Postfix) with ESMTPS id 7A90820B4C for ; Thu, 10 Mar 2016 23:59:45 +0100 (CET) Received: from mail.posteo.de (localhost [127.0.0.1]) by dovecot03.posteo.de (Postfix) with ESMTPSA id 3qLm1s31cFz5vML for ; Thu, 10 Mar 2016 23:59:45 +0100 (CET) Message-ID: <56E1FC61.8090400@posteo.de> Date: Thu, 10 Mar 2016 23:59:45 +0100 From: DK7FC 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: <56DEAE40.8000809@tiscali.co.uk> <56DEF9AE.7060203@posteo.de> <56E1F553.1080306@abelian.org> In-Reply-To: <56E1F553.1080306@abelian.org> X-Scan-Signature: 64a43ebf6189d3fbac7adf77f3718769 Subject: Re: LF: EbNaut from Todmorden Content-Type: multipart/alternative; boundary="------------080702070705080307090407" 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: 7296 This is a multi-part message in MIME format. --------------080702070705080307090407 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hi Paul, Am 10.03.2016 23:29, schrieb Paul Nicholson: > The coils of the T filter wound on ferrite toroids get very > hot very quickly. It's the ferrite producing the heat not > the wire. I must have the wrong flavour of ferrite so I > ordered some different ones (nice blue EPCOS ones) but they > wont arrive till Monday. Meanwhile I'll wind some air cored > coils for the filter. The ferrite seems to saturate. I recommend using iron power cores of -2 type (everywhere available, cheap, well working world wide). For your power level, T106-2 or maybe *T130-2* types are suitable. A T200-2 can be used for 1 kW when wound to j50 Ohm at LF. 73, Stefan --------------080702070705080307090407 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hi Paul,

Am 10.03.2016 23:29, schrieb Paul Nicholson:

The coils of the T filter wound on ferrite toroids get very
hot very quickly. It's the ferrite producing the heat not
the wire. I must have the wrong flavour of ferrite so I
ordered some different ones (nice blue EPCOS ones) but they
wont arrive till Monday. Meanwhile I'll wind some air cored
coils for the filter.

The ferrite seems to saturate.
I recommend using iron power cores of -2 type (everywhere available, cheap, well working world wide). For your power level, T106-2 or maybe T130-2 types are suitable. A T200-2 can be used for 1 kW when wound to j50 Ohm at LF.

73, Stefan
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