Return-Path: Received: (qmail 15382 invoked from network); 18 Mar 2002 18:14:02 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 18 Mar 2002 18:14:02 -0000 Received: (qmail 29748 invoked from network); 18 Mar 2002 18:14:00 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 18 Mar 2002 18:14:00 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16n351-0007Kb-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 18 Mar 2002 19:46:03 +0000 Received: from mail3.dada.it ([195.110.96.70] helo=mail.dada.it) by post.thorcom.com with smtp (Exim 3.33 #2) id 16n34z-0007KW-00 for rsgb_lf_group@blacksheep.org; Mon, 18 Mar 2002 19:46:01 +0000 Received: (qmail 4809 invoked from network); 18 Mar 2002 18:07:18 -0000 Received: from unknown (HELO cestag) (195.110.103.247) by mail.dada.it with SMTP; 18 Mar 2002 18:07:18 -0000 Message-ID: <002401c1cea7$a044ac80$f7676ec3@cestag> From: "cesare tagliabue" To: rsgb_lf_group@blacksheep.org Subject: LF: R: Loop Conductors and proximity effect Rdc Rac Date: Mon, 18 Mar 2002 19:05:56 +0100 MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.5 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: Content-transfer-encoding: 8bit

Hello John

I have found the Mesny's expression on an old university stenciled book where only the data were given, but some time ago, for purpose of include it in a program, I have elaborated an empiric expression that approximates sufficiently these data. That is:

q = ( 1 + .95 d / D )^2 - .22

Best 73 to all Cesare

Cesare Tagliabue I 5 TGC
WW-Loc JN53PS
e-mail: cestag@dada.it
url: http://www.dadacasa.com/i5tgc

-----Messaggio originale-----
Da: john sexton <computernetworks@excite.com>
A: rsgb_lf_group@blacksheep.org <rsgb_lf_group@blacksheep.org>
Data: lunedì 18 marzo 2002 17.46
Oggetto: LF: Loop Conductors and proximity effect Rdc Rac

Hi Paul,
From the interesting formula given by Cesare, the short answer to your question appears to be 1/2 inch.
I tried to find out more about Mesny's expression from the Internet, but it looks like you have to buy the book.
I wonder whether Cesare can be persuaded to tell us the formula that relates q to D/d? At a guess it appears to be logarithmic.
The second formula can be simplified to
Reff/Rrf = 1 + (q-1)*sqrt(1-Rdc/Rrf)
When D/d = 9, q = 1 so the second term disappears and Reff = Rrf.
73, John, G4CNN