Return-Path: Sender: (Marvin Kaye) To: lml Date: Mon, 25 Aug 2003 20:53:20 -0400 Message-ID: X-Original-Return-Path: Received: from aerosurf.net ([216.167.68.224] verified) by logan.com (CommuniGate Pro SMTP 4.1.1) with ESMTP id 2546509 for lml@lancaironline.net; Mon, 25 Aug 2003 18:27:40 -0400 Received: from ieee.org [208.252.252.82] by aerosurf.net with ESMTP (SMTPD32-6.06) id AEF06D50266; Mon, 25 Aug 2003 12:34:24 -1000 X-Original-Message-ID: <3F4A8D2E.1040304@ieee.org> X-Original-Date: Mon, 25 Aug 2003 15:26:54 -0700 From: "Charles R. Patton" Reply-To: charles.r.patton@ieee.org User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3) Gecko/20030312 X-Accept-Language: en-us, en MIME-Version: 1.0 X-Original-To: Lancair Mailing List Subject: Re: [LML] Transponder Antenna References: In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Bob Jude wrote: > If you want to increase the gain of your transponder antenna in the > horizontal plane you can make the ground plane in the shape of a cone > instead of a flat disc as shown in the attached picture. The conical shape > has the effect of flattening you antenna pattern. I've just posted a long response to Brent Regan about antenna patterns and I make a comment about this that I thought I'd repeat. You are right about the cone lowering the lobe of the radiation pattern, but having said that, I’m hoping that this is the picture of the roof, not the belly because I feel that in flight you want that lobe to angle flat or down slightly toward the probable location of the radar. Regards, Charles Patton LNC2 360JM