Return-Path: Received: (qmail 8563 invoked from network); 14 Feb 2002 09:36:33 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur-qfe1-smtp-plusnet.harl.plus.net with SMTP; 14 Feb 2002 09:36:33 -0000 Received: (qmail 21451 invoked from network); 14 Feb 2002 09:36:36 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 14 Feb 2002 09:36:36 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16bIGI-0006dx-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 14 Feb 2002 09:33:06 +0000 Received: from cmailg4.svr.pol.co.uk ([195.92.195.174]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16bIGH-0006ds-00 for rsgb_lf_group@blacksheep.org; Thu, 14 Feb 2002 09:33:05 +0000 Received: from modem-117.ar-gimilzor.dialup.pol.co.uk ([62.136.123.245] helo=lvm) by cmailg4.svr.pol.co.uk with smtp (Exim 3.13 #0) id 16bIFQ-0003ut-00 for rsgb_lf_group@blacksheep.org; Thu, 14 Feb 2002 09:32:12 +0000 Message-ID: <000601c1b53a$8f223980$f57b883e@lvm> From: "LAWRENCE MAYHEAD" To: "rsgb lf group" Subject: LF: Re. Vertical grounded tower for LF antenna. Date: Thu, 14 Feb 2002 09:23:30 -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: Mike G3XDV quite correctly pointed out that a gamma match could be used to feed a vert. tower. However I had dismissed this solution for two reasons 1) Climbing an 80 m tower to attach a feed wire is pretty daunting! 2) Even though Giulio's tower is 80m high it is still only only 0.036 of a wavelength so I wonder wether a gamma match could be made to work.Perhaps some EZNEC work would help here. For the moment I guess I'm back to my simple solution of a single sloping wire. After all this worked well for Dave G0MRFand the tower block. Were there some chance of another high support so as to increase the top load that of would be another story, but the "new ground " theory works with height as well as horizontal coverage and has the advantage of getting clear of the surroundings (trees etc) . 73s Laurie.