Return-Path: Received: (qmail 22393 invoked from network); 23 Jan 2001 13:55:06 -0000 Received: from unknown (HELO warrior-inbound.servers.plus.net) (212.159.14.227) by 10.226.25.101 with SMTP; 23 Jan 2001 13:55:06 -0000 Received: (qmail 11649 invoked from network); 23 Jan 2001 13:58:37 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 23 Jan 2001 13:58:37 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14L3mf-0000OX-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 23 Jan 2001 13:46:53 +0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from asterix.tee.gr ([212.70.193.140]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14L3md-0000OS-00 for rsgb_lf_group@blacksheep.org; Tue, 23 Jan 2001 13:46:52 +0000 Received: from teeserver.tee.gr (teeserver.tee.gr [212.70.193.130]) by asterix.tee.gr (8.9.3/8.9.3) with ESMTP id PAA06429 for ; Tue, 23 Jan 2001 15:46:23 +0200 (EET) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from odin ([212.70.201.118]) by teeserver.tee.gr (Netscape Messaging Server 4.1) with SMTP id G7MBLA00.K9X for ; Tue, 23 Jan 2001 15:46:22 +0200 Message-ID: <3.0.2.32.20010123154338.006d60e0@aurora.eexi.gr> X-Sender: sv1xv@aurora.eexi.gr (Unverified) X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.2 (32) Date: Tue, 23 Jan 2001 15:43:38 +0200 To: rsgb_lf_group@blacksheep.org From: "Costas Krallis" Subject: Re: LF: Mains Borne Noise In-reply-to: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: At 11:44 23/01/2001 +0100, you wrote: >>> Has anybody on the list got a "whole house" mains filter >>> installed at their QTH? > > Not a "whole house" mains filter, but a radio room > mains "filter". > > All main supply to my radio equipment is run via a > single phase isolation transformer,... The only problem with this approach is that in case of electrical fault or lightning strike one of the two earths conductors is at a high potential (voltage) in respect to the other. As the earth conductors are connected also to various metal objects (water pipes, equipment chassis etc) this situation can easily cause electrical shock or fire. A few years ago somebody tried a similar isolation system but conencted together the two earth conductors with an inductor made of thick electrical wire on a ferrite toroid. The coil had very small reactance at power frequency (50/60 Hz) but blocked conducted noise at radio frequencies. Costas +------------------------------------------------------------+ | Costas Krallis SV1XV * LOC KM18UA | | P.O.Box 3066 * FAX: +30-1-3811362 | | GR-10210 Athens * E-Mail: sv1xv@eexi.gr | | GREECE * PGP key: 0x3BDBBC34 | +------------------------------------------------------------+