Return-Path: Received: (qmail 2561 invoked from network); 21 Dec 2002 10:02:42 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 21 Dec 2002 10:02:42 -0000 Received: (qmail 23787 invoked from network); 21 Dec 2002 10:02:51 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 21 Dec 2002 10:02:51 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18PgS9-0007kJ-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 21 Dec 2002 10:01:53 +0000 Received: from [213.218.77.54] (helo=cmailENV2.svr.pol.co.uk) by post.thorcom.com with esmtp (Exim 4.10) id 18PgS9-0007kA-00 for rsgb_lf_group@blacksheep.org; Sat, 21 Dec 2002 10:01:53 +0000 Received: from [62.21.168.89] (helo=w8k3f0.freeler.nl) by cmailENV2.svr.pol.co.uk with esmtp (Exim 3.35 #1) id 18PgS8-0004wo-00 for rsgb_lf_group@blacksheep.org; Sat, 21 Dec 2002 10:01:52 +0000 Message-ID: <5.1.0.14.0.20021221095248.00aa2660@POP3.freeler.nl> X-Sender: FRE0000086604@POP3.freeler.nl X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Sat, 21 Dec 2002 10:03:04 +0100 To: rsgb_lf_group@blacksheep.org From: "Dick Rollema" In-reply-to: <5.1.0.14.0.20021220113920.00af1d00@gemini.herts.ac.uk> References: <2D280BB697C7EE4C979C5C89925418EF1BF5A5@TNS-FBU-2E-003.corp .telenor.no> MIME-Version: 1.0 Subject: Re: LF: Balanced vs. Unbalanced loops Content-Type: text/html; charset=windows-1252 X-Spam-Status: No, hits=0.0 required=5.0tests=noneversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Content-transfer-encoding: 8bit To All from PA0SE

Jim, M0BMU wrote:

I also find that external effects affect the depth of null you get - in my field strength measuring experiments, I found some locations where there was almost no null - This seemed to occur near overhead wires and power lines, which were presumably acting as parasitic antennas, inducing signals in the loop.

Also beware of conductors you don't see: underground cables, pipelines etc. When I do FS measurements I always walk around a bit at a location with my portable instrument. When moving around makes the FS fluctuate measurements will be unreliable. A road with lamp posts is always suspect as in our country the lamps are fed from an underground cable along the road.

73, Dick, PA0SE