Return-Path: Received: (qmail 5655 invoked from network); 10 Feb 2000 10:51:26 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by grants.core.plus.net.uk with SMTP; 10 Feb 2000 10:51:26 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12Ir2Y-0006Lh-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 10 Feb 2000 10:41:38 +0000 Received: from cmailg7.svr.pol.co.uk ([195.92.195.177]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 12Ir2X-0006Lc-00 for rsgb_lf_group@blacksheep.org; Thu, 10 Feb 2000 10:41:37 +0000 Received: from modem-4.doriath.dialup.pol.co.uk ([62.136.156.4] helo=lvm) by cmailg7.svr.pol.co.uk with smtp (Exim 3.13 #0) id 12Ir2O-0003Wg-00 for rsgb_lf_group@blacksheep.org; Thu, 10 Feb 2000 10:41:29 +0000 Message-ID: <000201bf73b3$65a7cfe0$049c883e@lvm> From: "LAWRENCE MAYHEAD" To: "rsgb lf group" Subject: LF: G3KEV DX Expedition. Date: Thu, 10 Feb 2000 10:40:49 -0000 MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 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: Content-transfer-encoding: 8bit

It seems to me that there are several problems with this antenna system.I am not refering to the DANGERS of the tower which do seem to be troubling Mal.No I am more concerned with the efficiency of the structure.For the following reasons:-

1) The use of 3 inverted L ants on the same support will imply 3 vertical wires which will result in excessive capacity to ground and indeed to the tower.This will mean more antenna current low down,defeating the object of the high support.

2) The same applies to the sloping top loading,as these wires approach ground they too will carry excessive current low down.

3)The use of radials only 1m above ground,this will be self defeating since they will couple closely into the ground losses, they could as well have been placed on the ground where they would not be a hazard to people animals etc.

Finally I would have been concerned about this antenna having such a high efficency (ie high radation resistance) that care would have been needed to keep the ERP within legal limits,however the construction as proposed is not in my opinion likely to be anywhere near as efficient as it might be.73s Laurie.