Return-Path: Received: (qmail 29977 invoked from network); 29 Jun 2002 02:15:55 -0000 Received: from marstons.services.quay.plus.net (212.159.14.223) by mailstore with SMTP; 29 Jun 2002 02:15:55 -0000 Received: (qmail 6772 invoked by uid 10001); 29 Jun 2002 02:19:44 -0000 Received: from post.thorcom.com (193.82.116.70) by marstons.services.quay.plus.net with SMTP; 29 Jun 2002 02:19:44 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 17O7iT-0001Xf-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 29 Jun 2002 03:12:01 +0100 Received: from mail4.mx.voyager.net ([216.93.66.203]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17O7iS-0001Xa-00 for rsgb_lf_group@blacksheep.org; Sat, 29 Jun 2002 03:12:00 +0100 Received: from k6500 (d21.as3.mpls.mn.voyager.net [169.207.249.245] (may be forged)) by mail4.mx.voyager.net (8.11.6/8.10.2) with SMTP id g5T2Bv696729 for ; Fri, 28 Jun 2002 22:11:57 -0400 (EDT) From: "WE0H" To: rsgb_lf_group@blacksheep.org Subject: LF: RE: 47A of loop current: No sweat! Date: Fri, 28 Jun 2002 21:12:02 -0500 Message-ID: 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 IMO, Build 9.0.2416 (9.0.2911.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Importance: Normal In-reply-to: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Fire 'em up there, wild Bill!!! Mike>WE0H http://www.geocities.com/we0h/lf.html -----Original Message----- From: majordom@post.thorcom.com [mailto:majordom@post.thorcom.com]On Behalf Of Ashlock,William Sent: Friday, June 28, 2002 5:06 PM To: 'rsgb_lf_group@blacksheep.org' Subject: LF: 47A of loop current: No sweat! Mal and group, I was just pricing out various sizes of copper pipe at the local builders department store for the next "dream" (or is that "pie in the sky"?) loop antenna. Turns out 2" ID pipe is $18 per 10 ft section which would yeild a 0.04ohm Rac on a 50'x50' loop, neglecting soil loss. Was actually contemplating reducing the size to about 1/4th the area to allow raising and lowering the loop to measure various losses without a reduction in the basic radiated power @ an input of 1w. Then I did a little 'wild math' (or call it 'wildfire' math) to determine the dimensions of a 47A loop (still at 1w to keep it legal) that would have the same radiation as my 50'x50' 1/2" pipe loop. Considering my present 1.8A, going to 47A would allow a 47/1.8 = ~25x reduction in loop area. The new area would be 2500/25 = 100sq ft or 10ft per side. So far, so good. But in order to achieve 47A @ 1w the Rac of the new loop would have to be 1/(47^2)= .00045 ohms. I did a bit of manipulation of the formula for Rac Vs conductor diameter for a 40ft long copper conductor and came up with: Diameter (in inches) = .016/Rac. Using an Rac of .00045 the diameter comes to 35 inches. Well.... not impossible! And could be fashioned from .01" thick copper foil - maybe $200 worth! Just thought you might want to know...... TGIF! Bill A _____________________________________________________________________ This message has been checked for all known viruses by UUNET delivered through the MessageLabs Virus Control Centre. For further information visit http://www.uk.uu.net/products/security/virus/