Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1927E3800011A; Thu, 15 Sep 2011 15:09:36 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1R4HI8-0005pz-B1 for rs_out_1@blacksheep.org; Thu, 15 Sep 2011 20:08:08 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1R4HI4-0005pq-3R for rsgb_lf_group@blacksheep.org; Thu, 15 Sep 2011 20:08:04 +0100 Received: from mailout-de.gmx.net ([213.165.64.23]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1R4HI2-0000fH-2x for rsgb_lf_group@blacksheep.org; Thu, 15 Sep 2011 20:08:04 +0100 Received: (qmail invoked by alias); 15 Sep 2011 19:07:55 -0000 Received: from p4FD0D767.dip.t-dialin.net (EHLO Clemens04) [79.208.215.103] by mail.gmx.net (mp035) with SMTP; 15 Sep 2011 21:07:55 +0200 X-Authenticated: #17214767 X-Provags-ID: V01U2FsdGVkX1/HMGg6prTHLHRErAHYvXFmY9JpcHgJCFAYrFEIJE ZBndZOTS+Ho+xq Message-ID: <000f01cc73da$c64bc160$1502a8c0@Clemens04> From: "Clemens Paul" To: References: <4E6554E1.1050808@gmail.com> <4E692FB6.60306@o2.co.uk> Date: Thu, 15 Sep 2011 21:07:52 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3664 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3664 X-Y-GMX-Trusted: 0 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: Re: The Smith Chart Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 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: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:507847520:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40d64e724d701da5 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi Peter, my ARRL Antenna Handbook from 1974 also shows the chart with the R line orientated vertically, zero Ohm on top,maximum R on bottom. My 'Hf Antennas for all Locations' from 1991 has it also vertically orientaded but vice versa, i.e. zero Ohm on bottom,maximum R on top. For sure it's just a 'matter of taste' how you rotate the chart. Maybe the authors thought it would be better for their purposes when visualizing what they tried to explain. On the other hand since many decades vector network analyzers (VNA) e.g. like my HP 8407A from around 1970 always have had zero ohm at the left and infinity ohms at the right on their display. So it seems to have become a convention to print the charts with the same orientation when VNAs became more common. 73 Clemens DL4RAJ ----- Original Message ----- From: "Peter Dodd" To: Sent: Thursday, September 08, 2011 11:12 PM Subject: LF: The Smith Chart > Earlier literature such as: > > The Services Textbook of Radio (1958) > ARRL Antenna Book 14th edition (1984) > HF Antennas for all Locations 2nd edition (1993) > > > describe a Smith Chart with the centre straight line of R j0 vertically > orientated. > > All later and current literature containing Smith Charts show the centre > straight line of R j0 horizontally orientated with maximum R to the right, but > without explanation. > > Is there a good technical reason for this change or is it just fashion. > > Regards > > Peter, G3LDO > > > > > ----- > eMail ist virenfrei. > Von AVG überprüft - www.avg.de > Version: 10.0.1392 / Virendatenbank: 1520/3883 - Ausgabedatum: 07.09.2011