Return-Path: Received: (qmail 16049 invoked from network); 9 Jan 2001 13:24:54 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by 10.226.25.101 with SMTP; 9 Jan 2001 13:24:54 -0000 Received: (qmail 21448 invoked from network); 9 Jan 2001 13:28:14 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 9 Jan 2001 13:28:14 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14Fyhq-0003OS-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 09 Jan 2001 13:20:54 +0000 Received: from mail6.svr.pol.co.uk ([195.92.193.212]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14Fyhp-0003ON-00 for rsgb_lf_group@blacksheep.org; Tue, 09 Jan 2001 13:20:53 +0000 Received: from modem-188.fluorine.dialup.pol.co.uk ([62.136.8.188] helo=default) by mail6.svr.pol.co.uk with smtp (Exim 3.13 #0) id 14Fyhf-00030s-00 for rsgb_lf_group@blacksheep.org; Tue, 09 Jan 2001 13:20:43 +0000 Message-ID: <000001c07a3e$35d6bb40$bc08883e@default> From: "MAL HAMILTON" To: rsgb_lf_group@blacksheep.org Subject: LF: Re: Loading coils / Measuring receivers Date: Mon, 8 Jan 2001 18:58:31 -0000 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.5 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: -----Original Message----- From: James Moritz To: rsgb_lf_group@blacksheep.org Date: 08 January 2001 18:14 Subject: LF: Loading coils / Measuring receivers Dear LF group, OK on the loading coils - my current loading coil is over 500mm diameter, so ready-made containers to fit it are hard to come by. I'm suprised that people have had success with coils exposed to the rain, I found with mine that this drastically reduced the Q once water got in between the turns. Hello Jim. My loading coils are outside and I do not suffer from any detrimental affects in hot sun, rain, frost or snow or rain of any sort. The swr meter shows virtually no change in changing wx conditions. I do have a fairly high mast at 120 feet supporting 3 x inv L antennas with 250 feet horizontal top sections. The coils are wound with 2.5 mm multi strand plastic insulated wire. My coils are 6 feet above ground and vertically orintated and I have never noticed any water or snow etc in between turns. The coils also run cool, not even warm. I have a fairly elaborate insulated ground system. I can run around 1w erp. The coils at the base of the antenna vertical are matched to the 50 ohm coax feed and are about 90 feet away from the shack. Not much chance of my shack catching fire. Ever since I started on LF some 3 years ago I never had any problems with the installation, no fet, insulator, wire etc failures. I have built the installation to match 50 ohms and always tune for minimum swr, this always coincides with max rf output. I NEVER tune for max SMOKE!!!!!!!!!!! This could be a recipe for disaster. I do not have any PA protection. I monitor SWR for any change and so far no problems. 73 de Mal/G3KEV Cheers, Jim Moritz 73 de M0BMU