Return-Path: Received: (qmail 18039 invoked from network); 19 Mar 2002 16:43:39 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by exhibition.plus.net with SMTP; 19 Mar 2002 16:43:39 -0000 Received: (qmail 19306 invoked from network); 19 Mar 2002 16:43:35 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 19 Mar 2002 16:43:35 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16nO5f-0002H8-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 19 Mar 2002 18:12:07 +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 16nO5d-0002H3-00 for rsgb_lf_group@blacksheep.org; Tue, 19 Mar 2002 18:12:06 +0000 Received: (qmail 12618 invoked from network); 19 Mar 2002 16:33:24 -0000 Received: from unknown (HELO cestag) (195.110.102.8) by mail.dada.it with SMTP; 19 Mar 2002 16:33:24 -0000 Message-ID: <001101c1cf63$ac468820$08666ec3@cestag> From: "cesare tagliabue" To: rsgb_lf_group@blacksheep.org Subject: LF: R: Proximity effect Date: Tue, 19 Mar 2002 17:31:59 +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 Dick

I've noted the great difference between the values reported by Mesny and those appearing in the graph you have sent. I think the difference may be explained as follows: the graph refers to two wires, where the magnetic field is rarefied only in the sides facing each other. In the case of a single layer coil, except the first and the last turn, the magnetic field is rarefied in both sides of each wire, so reducing further on the useful area and consequently increasing the RF resistance. Any comment welcome 73 Cesare

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

-----Messaggio originale-----
Da: Dick Rollema <d.w.rollema@freeler.nl>
A: LF-Group <rsgb_lf_group@blacksheep.org>
Data: martedì 19 marzo 2002 12.54
Oggetto: LF: Proximity effect

Dr. OM,

Perhaps this has been reported bnefore but just in case it has not. Terman's RADIO ENGINEERS' HANDBOOK (first Edition, Sixth Impression) contains useful information on the proximity effect and the ratio of ac to dc resistance of isolated litz wire: pages 36 and 37.
Attached a sample that hopefully passes the reflector.

73, Dick, PA0SE