Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 04C4A380000EA; Thu, 14 Feb 2013 19:53:48 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1U69XR-0008Gj-SO for rs_out_1@blacksheep.org; Fri, 15 Feb 2013 00:52:29 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1U69XR-0008Ga-Aj for rsgb_lf_group@blacksheep.org; Fri, 15 Feb 2013 00:52:29 +0000 Received: from mail-ie0-f172.google.com ([209.85.223.172]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.77) (envelope-from ) id 1U69XP-0000cq-1u for rsgb_lf_group@blacksheep.org; Fri, 15 Feb 2013 00:52:28 +0000 Received: by mail-ie0-f172.google.com with SMTP id c10so4146523ieb.31 for ; Thu, 14 Feb 2013 16:52:05 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:content-type:content-transfer-encoding; bh=/QYnChIX/CfD2CZ7Q/M91/TAgADiupC6ZTSsKjdFH/k=; b=nu8QpipDtHoHTw+izbKenq9Ti8jFFc2iO+AhLWEaxtJDXkVL898czmEkcZ7HOt+JPN TrwqYbR8hyZFCpMlgKrAPleZjI26EmzgrpkEvEEWz4+4xx9xk6qtoDlWTzi5iP2/KQZV p0JaedxVOUzVt0/82MutT0iGBQiBLr7euCQP87HSERBt1eahtkImZCgts7GsQKF+7hjj 0AZ41kT0/Vs9N95Idwp1q9YtblCvqG18PWZ5vlN+BU5u95/+IYg4+jtgLNdCbshtLmrH iCJz4uqTqP/olaEG4d39Msc1AQrnr6rAeaDhRnBL6nFI0qw6VVU2HLYhsZ8o1ROYEqxL VWiA== MIME-Version: 1.0 X-Received: by 10.50.87.201 with SMTP id ba9mr1225615igb.83.1360889524970; Thu, 14 Feb 2013 16:52:04 -0800 (PST) Received: by 10.50.28.47 with HTTP; Thu, 14 Feb 2013 16:52:04 -0800 (PST) In-Reply-To: <511D8408.8030709@iup.uni-heidelberg.de> References: <511D8408.8030709@iup.uni-heidelberg.de> Date: Fri, 15 Feb 2013 11:52:04 +1100 Message-ID: From: Dimitrios Tsifakis To: rsgb_lf_group@blacksheep.org X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Stefan, A photo of the coil can be seen here: http://people.physics.anu.edu.au/~dxt103/500/ [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.223.172 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (dtsifakis[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: ce0e5a4ae990e5a63db3ab7aea21191b Subject: Re: LF: how to increase the Q of my loading coil? Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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-AUTHENTICATION: mtain-mk05.r1000.mx.aol.com ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d6189511d871c5268 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi Stefan, A photo of the coil can be seen here: http://people.physics.anu.edu.au/~dxt103/500/ The operating position is inside a little metal garden shed. I have a wooden bench and it sits on that. There is maybe 0.5 m of space or more between the inductor and the shed walls. Ground losses are estimated to be a bit less than 20 ohm. This varies a bit with the WX, currently after a bit of rain think it is probably around 17 or 18 ohm. There is clay under the soil, which I think is good news when it comes to conductivity :-) Going from 27 ohm to say (Q=3D1000) about 20 ohm antenna impedance, would result in a small but very welcome antenna current increase... 73, Dimitris 2013/2/15 Stefan Sch=E4fer : > Hi Dimitris, > > Do you have a photo showing the coil in its position? > > What are the ground losses, about? R coil =3D 9 Ohm with that Q and XL...= . > Litz wire helps of course, if you have enough... > > 73, Stefan/DK7FC > > > Am 15.02.2013 01:31, schrieb Dimitrios Tsifakis: > >> Hello group, >> >> I would like to increase the Q of my loading coil for 475 kHz. . It >> consists currently of a 20-litre plastic bucket with standard house >> 240V electrical wire (with PVC jacket). I measured the Q and found it >> to be about 220 (XL is about 2 kohm). I do have some Litz wire I can >> use. I also have a piece of large diameter (25 cm) storm water pipe, >> which I think is made of PVC. Would you recommend using a PVC former >> or should I look for a more exotic material (glass/porcelain)? Would >> you think the inter-turn capacitance is very detrimental and some >> exotic winding technique would yield better results? >> >> I understand that ground losses are bigger in my case than the >> inductor losses, but I would like to address the inductor first. >> >> 73, Dimitris VK1SV >> > >