Return-Path: Received: (qmail 18586 invoked from network); 21 Mar 2000 10:15:22 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by dimple.core.plus.net.uk with SMTP; 21 Mar 2000 10:15:22 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12XLUU-0006kf-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 21 Mar 2000 10:02:22 +0000 Received: from mashie.force9.net ([195.166.128.30]) by post.thorcom.com with smtp (Exim 3.02 #1) id 12XLUT-0006ka-00 for rsgb_lf_group@blacksheep.org; Tue, 21 Mar 2000 10:02:21 +0000 Received: (qmail 8607 invoked from network); 21 Mar 2000 10:02:13 -0000 Received: from rack.servers.plus.net.uk (212.159.2.65) by mashie.force9.net with SMTP; 21 Mar 2000 10:02:13 -0000 Received: (qmail 10386 invoked from network); 21 Mar 2000 10:01:12 -0000 Received: from unknown (HELO main) (212.159.68.129) by rack.servers.plus.net.uk with SMTP; 21 Mar 2000 10:01:12 -0000 Message-ID: <002701bf931d$406d41e0$0600a8c0@main> From: "Dave" To: "LF Group" Subject: LF: Still learning Date: Tue, 21 Mar 2000 09:32:29 -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 5.00.2014.211 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: Dear all. Last night whilst the tx was sending a QRS call on 71.8 I went outside to check that there was no corona discharge from the antenna, easy to see in the dark. No problems were seen but I noticed a crackling noise behind me. Closer investigation revealed that it was coming from the ground at the base of the antenna support mast which is strapped to a fir tree. Small sparks could be seen amongst the undergrowth where the mast touched the ground. This was obviously a waste of valuable energy! I decided to earth the pole, then at least it would no longer be a lossy structure, just some additional capacitance. After I had done this three things happened, the resonant frequency went down, the match changed and, when the ATU was re-adjusted, the antenna current rose by 10% for the same power input. This must be due to higher Q because of less loss. Well worth doing. Fire-risk reduced and power increased! Look out for lossy structures near the antenna and either insulate them they will then be live... ) or earth them solidly. 73, Dave G3YXM.