Return-Path: Received: (qmail 26542 invoked from network); 13 Dec 2002 19:22:34 -0000 Received: from netmail02.services.quay.plus.net (212.159.14.221) by mailstore with SMTP; 13 Dec 2002 19:22:34 -0000 Received: (qmail 23197 invoked by uid 10001); 13 Dec 2002 19:22:29 -0000 Received: from post.thorcom.com (193.82.116.70) by netmail02.services.quay.plus.net with SMTP; 13 Dec 2002 19:22:29 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18MvNO-0001xd-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 13 Dec 2002 19:21:34 +0000 Received: from [210.86.15.147] (helo=mta204-rme.xtra.co.nz) by post.thorcom.com with esmtp (Exim 4.10) id 18MvNM-0001xU-00 for rsgb_lf_group@blacksheep.org; Fri, 13 Dec 2002 19:21:33 +0000 Received: from mta1-rme.xtra.co.nz ([210.86.15.140]) by mta204-rme.xtra.co.nz with ESMTP id <20021213192055.JALV1843.mta204-rme.xtra.co.nz@mta1-rme.xtra.co.nz> for ; Sat, 14 Dec 2002 08:20:55 +1300 Received: from xtr743187 ([210.86.47.132]) by mta1-rme.xtra.co.nz with SMTP id <20021213192053.KAKY688.mta1-rme.xtra.co.nz@xtr743187> for ; Sat, 14 Dec 2002 08:20:53 +1300 Message-ID: <001301c2a2dd$035a0ae0$842f56d2@xtr743187> From: "Vernall" To: rsgb_lf_group@blacksheep.org References: <2D280BB697C7EE4C979C5C89925418EF368FCE@TNS-FBU-2E-003.corp.telenor.no> Date: Sat, 14 Dec 2002 08:19:34 +1300 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: (Off Topic) PC mains filter for 136kHz interference Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=0.5 required=5.0tests=REFERENCES,SPAM_PHRASE_00_01,USER_AGENT_OEversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Jan_Martin LA8AK, > Wonder if somebody has any experience in building mains filters for the PC ? An alternative approach is to insert a mains isolating transformer at the PC (and also watch out for "bypassing" if there are computer peripheral devices with mains PSUs). Most of the commercially made filters, such as IEC chassis mounting sockets with filter inside, have only a millihenry or so of "choke" and that can not provide high attenuation at LF. I was lucky enough to come across a mains filter that was multi-stage, with good sized potcores, and that is reasonably effective on LF. 73, Bob ZL2CA