Return-Path: Received: (qmail 22114 invoked from network); 3 Dec 2002 17:17:35 -0000 Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 3 Dec 2002 17:17:35 -0000 Received: (qmail 20813 invoked from network); 3 Dec 2002 17:17:18 -0000 Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 3 Dec 2002 17:17:17 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18JGbV-0002Sl-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 03 Dec 2002 17:13:01 +0000 Received: from [194.73.73.81] (helo=tungsten.btinternet.com) by post.thorcom.com with esmtp (Exim 4.10) id 18JGbT-0002Sc-00 for rsgb_lf_group@blacksheep.org; Tue, 03 Dec 2002 17:12:59 +0000 Received: from host213-121-126-226.in-addr.btopenworld.com ([213.121.126.226] helo=dellboy) by tungsten.btinternet.com with smtp (Exim 3.22 #16) id 18JGbS-0003V8-00 for rsgb_lf_group@blacksheep.org; Tue, 03 Dec 2002 17:12:58 +0000 Message-ID: <006701c29aef$54db13a0$1700a8c0@home> From: "Dave Pick" To: "LF Group" Date: Tue, 3 Dec 2002 17:13:42 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4920.2300 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Flaming aerials! Content-Type: text/html; charset=windows-1252 X-Spam-Status: No, hits=1.0 required=5.0tests=SPAM_PHRASE_00_01,SUPERLONG_LINE,USER_AGENT_OEversion=2.42 X-Spam-Level: * Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Content-transfer-encoding: 8bit

Dear all, especially Peter.

I had a bit of a problem on 73k today, the TX started tripping during my QSO with G3LDO at about 12:30. Eventually I had to reduce the power to a few hundred Watts to sign off.

I went outside, down the full length of the garden to the ATU to see if anything was wrong. All seemed well but I could hear a "crackling" noise and couldn't figure out where it was coming from. I eventually looked up at the top of the tree where the aerial passed over a perspex "Y" on the top of the pole... It was alight! A couple of years worth of polution must have made it conductive enough for the RF to arc through it to the metal supporting pole (which is earthed). I watched it with trepidation lest any burning pieces should drop off and set light to the tree, luckily this didn't happen and eventually it went out.

I have since replaced the top piece with a new design, let's see how long that lasts!

This sort of thing always happens when I "fire-up" on 73k, the Voltages are just so high..

You can just see the flames on this picture.

http://www.wireless.org.uk/images/firesky2.jpg

73.

Dave

G3YXM.