Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-me02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 8D4E7380005B2; Wed, 17 Aug 2011 07:15:09 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Qte4M-00082w-6b for rs_out_1@blacksheep.org; Wed, 17 Aug 2011 12:13:58 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Qte4L-00082n-Ps for rsgb_lf_group@blacksheep.org; Wed, 17 Aug 2011 12:13:57 +0100 Received: from mhost02c.leeds.ac.uk ([129.11.76.154]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Qte4J-00039u-Em for rsgb_lf_group@blacksheep.org; Wed, 17 Aug 2011 12:13:57 +0100 Received: from APOLLO1.ds.leeds.ac.uk (apollo1.leeds.ac.uk [129.11.5.4]) by mhost02c.leeds.ac.uk (8.14.4/8.14.4) with ESMTP id p7HBDntX020706 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT) for ; Wed, 17 Aug 2011 12:13:49 +0100 (BST) Received: from HERMES8.ds.leeds.ac.uk ([fe80::39ce:23e:d0b5:7e24]) by APOLLO1.ds.leeds.ac.uk ([129.11.5.4]) with mapi; Wed, 17 Aug 2011 12:13:49 +0100 From: Chris Trayner To: "rsgb_lf_group@blacksheep.org" Date: Wed, 17 Aug 2011 12:13:48 +0100 Thread-Topic: LF: Re: Re: ferrite coil Thread-Index: AcxczrzILuMe7oHcSw6xzVEK3Q+PCQ== Message-ID: <1F2432B7-6BD8-4A55-BD8F-41E083CDA7AA@leeds.ac.uk> References: <005f01cc5c32$66a39ae0$0401a8c0@xphd97xgq27nyf> <182D3176BF9144939EF13D0CBAC4921F@JimPC> <000d01cc5cc3$43001a00$0401a8c0@xphd97xgq27nyf> In-Reply-To: <000d01cc5cc3$43001a00$0401a8c0@xphd97xgq27nyf> Accept-Language: en-US, en-GB Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US, en-GB MIME-Version: 1.0 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Re: Re: ferrite coil Content-Type: text/plain; charset="us-ascii" 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=TO_ADDRESS_EQ_REAL 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: 0:2:379844096:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d608a4e4ba2bd68f6 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Mal and others, > The Collins equipment used this method in their VFO'S, permeability tunin= g ... as did cheap-and-nasty push-button car radios. (Well, they probably wer= en't nasty by the standards of the day, and certainly not cheap.) You pulle= d out the push-button (which I think engaged it mechanically with the tunin= g dial), tuned (which wound the core in and out), then pushed the button ba= ck in again to leave the core at that setting. > There seems to be some confusion about Variometer. A Variometer consists = of > two coils in series with one rotated within the other to vary Inductance Someone earlier mentioned his LF Rx ant near his remote-controlled garage d= oor. I think he's missed an opportunity here - remove the metal of the door= , replace it with a large coil, and he could have the largest remote-contro= lled variometer in the world! Now there's style ... 73, Chris G4OKW ----------------------- Dr Chris Trayner School of Electronic & Electrical Engineering, The University of Leeds, Leeds LS2 9JT, United Kingdom Tel: +44 113 34 32053 Fax: +44 113 34 32032