Return-Path: Received: (qmail 13467 invoked from network); 5 Feb 2001 14:50:26 -0000 Received: from unknown (HELO warrior-inbound.servers.plus.net) (212.159.14.227) by 10.226.25.101 with SMTP; 5 Feb 2001 14:50:26 -0000 Received: (qmail 5545 invoked from network); 5 Feb 2001 14:54:07 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 5 Feb 2001 14:54:07 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14Pmtv-0006jv-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 05 Feb 2001 14:45:55 +0000 Received: from bob.dera.gov.uk ([192.5.29.90]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14Pmtu-0006jq-00 for rsgb_lf_group@blacksheep.org; Mon, 05 Feb 2001 14:45:54 +0000 X-Priority: 3 X-MSMail-Priority: Normal Received: by bob.dera.gov.uk; (8.8.8/1.3/10May95) id OAA12164; Mon, 5 Feb 2001 14:47:24 GMT Received: (qmail 21600 invoked from network); 5 Feb 2001 15:38:44 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from gauntlet.mail.dera.gov.uk (172.16.9.10) by baton.dera.gov.uk with SMTP; 5 Feb 2001 15:38:44 -0000 Received: by gauntlet.mail.dera.gov.uk; id PAA11638; Mon, 5 Feb 2001 15:29:04 GMT Received: from unknown(10.71.64.31) by gauntlet.mail.dera.gov.uk via smap (3.2) id xma011457; Mon, 5 Feb 01 15:28:27 GMT Received: from FRN-MAIL-3.dera.gov.uk (unverified) by mailguard.dera.gov.uk (Content Technologies SMTPRS 4.1.5) with ESMTP id for ; Mon, 5 Feb 2001 14:48:37 +0000 Received: by frn-mail-3.dera.gov.uk with Internet Mail Service (5.5.2650.21) id <1L20VHRJ>; Mon, 5 Feb 2001 14:44:35 -0000 Message-ID: <65AECDF1F89AD411900400508BFC869F0D759A@pdw-mail-1.dera.gov.uk> From: "Talbot Andrew" To: rsgb_lf_group@blacksheep.org Subject: LF: RE: Interference from fluorescent tube Date: Mon, 5 Feb 2001 13:16:31 -0000 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: text/html; charset=windows-1252 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit

I also noticed bad interference from a fluorescent tube - wondered why the waterfall background got lighter just after I'd started watching it in real time once. Here, the light is located 3m under the top load wires of the antenna and adds 10 - 15dB to the noise floor on 137 when switched on even though it is a new light fitting. Fortunately I spotted this at the time of the shack rebuild and added another light into the wiring for use when receiving - a normal filament spotlight.

'JNT

-----Using my portable field strengh meter as a receiver I found the culprit to be a fluorescent tube mounted over the dresser in our kitchen. The noise is already present with the tube switched off and increases upon switching on.

When I remove the tube the noise disappears.

Cleaning the tube on its outside to remove grease and dirt did not help





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