Return-Path: <owner-rsgb_lf_group@blacksheep.org> Received: (qmail 31140 invoked from network); 1 Apr 2003 13:41:39 -0000 Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 1 Apr 2003 13:41:39 -0000 Content-Transfer-Encoding: 8bit Received: (qmail 24044 invoked from network); 1 Apr 2003 13:41:36 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 1 Apr 2003 13:41:36 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.14) id 190Lvy-0006nk-76 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 01 Apr 2003 14:36:14 +0100 Received: from [134.58.240.42] (helo=rusty.kulnet.kuleuven.ac.be) by post.thorcom.com with esmtp (Exim 4.14) id 190Lvm-0006nb-N5 for rsgb_lf_group@blacksheep.org; Tue, 01 Apr 2003 14:36:02 +0100 Received: from localhost (localhost [127.0.0.1]) by rusty.kulnet.kuleuven.ac.be (Postfix) with ESMTP id 385CB1D72A7 for <rsgb_lf_group@blacksheep.org>; Tue, 1 Apr 2003 15:35:32 +0200 (CEST) Received: from antonius.kulnet.kuleuven.ac.be (antonius.kulnet.kuleuven.ac.be [134.58.240.73]) by rusty.kulnet.kuleuven.ac.be (Postfix) with ESMTP id DB3901D729F for <rsgb_lf_group@blacksheep.org>; Tue, 1 Apr 2003 15:35:31 +0200 (CEST) Received: from dell-rik.fys.kuleuven.ac.be (pc-10-33-165-177.fys.kuleuven.ac.be [10.33.165.177]) by antonius.kulnet.kuleuven.ac.be (Postfix) with ESMTP id 99F8F4C0D0 for <rsgb_lf_group@blacksheep.org>; Tue, 1 Apr 2003 15:35:31 +0200 (CEST) Message-ID: <5.1.0.14.0.20030401151940.02e6c578@u0019445.kuleuven.be> X-Sender: u0019445@u0019445.kuleuven.be X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Tue, 01 Apr 2003 15:36:27 +0200 To: rsgb_lf_group@blacksheep.org From: "Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be> In-reply-to: <000f01c2f844$e1abea40$d3e8fc3e@l8p8y6> References: <000501c2f7a3$1f8d9ea0$07d2fc3e@ian> <003101c2f7b3$1954f500$cbe8fc3e@l8p8y6> <001a01c2f7c3$800834a0$92e086d4@erica> MIME-Version: 1.0 X-Virus-Scanned: by KULeuven Antivirus Cluster Subject: Re: LF: Re: Loading coils Content-Type: text/plain; charset=us-ascii; format=flowed X-Spam-Status: No, hits=-22.9 required=5.0tests=EMAIL_ATTRIBUTION,IN_REP_TO,REFERENCES,REPLY_WITH_QUOTESversion=2.51 X-Spam-Checker-Version: SpamAssassin 2.51 (1.174.2.5-2003-03-20-exp) X-SA-Exim-Scanned: Yes Sender: <owner-rsgb_lf_group@blacksheep.org> Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false At 12:49 1/04/2003 +0100, G3KEV wrote: >Its a question of requirements. > >1. These Decca coils were used only on TX and 10/15 db loss was acceptable >by putting these coils in a metal cage for environmental reasons. 10 to 15dB coil loss means 90% to 97% of all power lost (= transformed to heat) in the coil. I wonder why the Decca guys went through all the trouble to built large antennas with an acceptable efficiency and then decided to use 90 to 97% of the power just to heat the loadingcoil ? This apart from the fact that dissipating more than 90% of the Decca power in a coil would probably melt it. >2. Heated coils generate noise, in fact the coils should be kept cold, but >again in a TX only mode it does not matter. I doubt that the few nV noise generated by a warm coil (or resistor) are significant. Atmospheric and manmade noise will be many 10dB's stronger. >The above info is old hat for those in the know, it would appear some have >led sheltered lives in the wireless world. Aha ... that might be my problem ! 73, Rik ON7YD