Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dl04.r1000.mx.aol.com (Internet Inbound) with ESMTP id C12C73800009C; Wed, 14 Sep 2011 05:14:01 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1R3lWs-00023B-UT for rs_out_1@blacksheep.org; Wed, 14 Sep 2011 10:13:14 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1R3lWs-000232-Ja for rsgb_lf_group@blacksheep.org; Wed, 14 Sep 2011 10:13:14 +0100 Received: from smtp-vbr1.xs4all.nl ([194.109.24.21]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1R3lWq-0007n2-EY for rsgb_lf_group@blacksheep.org; Wed, 14 Sep 2011 10:13:14 +0100 Received: from pc-roelof (ndb.demon.nl [82.161.81.65]) by smtp-vbr1.xs4all.nl (8.13.8/8.13.8) with ESMTP id p8E9D6YF083233 for ; Wed, 14 Sep 2011 11:13:11 +0200 (CEST) (envelope-from roelof@ndb.demon.nl) To: rsgb_lf_group@blacksheep.org References: <4E6E0AD4.4838.465714@mike.dennison.ntlworld.com> <1315833746.18312.YahooMailNeo@web29503.mail.ird.yahoo.com> <1315926429.28889.YahooMailNeo@web29518.mail.ird.yahoo.com> Date: Wed, 14 Sep 2011 11:13:04 +0200 MIME-Version: 1.0 From: "Roelof Bakker" Message-ID: In-Reply-To: <1315926429.28889.YahooMailNeo@web29518.mail.ird.yahoo.com> User-Agent: Opera Mail/11.51 (Win32) X-Virus-Scanned: by XS4ALL Virus Scanner X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes Subject: Re: LF: Simple yet reliable method for measuring Q? Content-Transfer-Encoding: 7bit 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: 0:2:396227808:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d4ad24e7070582a19 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hello Daniele, It can be easily done, using the "3 dB method". This method does load the LC circuit very lightly, so the measured Q is close to the unloaded Q. For a further read, I suggest W7ZOI's article here: http://w7zoi.net/2faces/twofaces.html This is also an interesting read: http://w7zoi.net/coilq.pdf 73, Roelof, pa0rdt