Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dc05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 50897380001BB; Tue, 27 Sep 2011 07:50:02 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1R8W9o-0003AS-93 for rs_out_1@blacksheep.org; Tue, 27 Sep 2011 12:49:04 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1R8W9n-0003AJ-Oj for rsgb_lf_group@blacksheep.org; Tue, 27 Sep 2011 12:49:03 +0100 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1R8W9m-00032H-7E for rsgb_lf_group@blacksheep.org; Tue, 27 Sep 2011 12:49:03 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id p8RBn0qb025669 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 27 Sep 2011 13:49:01 +0200 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id p8RBn0Vk004511 for ; Tue, 27 Sep 2011 13:49:00 +0200 Message-ID: <4E81B80E.3030201@iup.uni-heidelberg.de> Date: Tue, 27 Sep 2011 13:48:30 +0200 From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <16BC8B3CA8672445BC2A29B4C14A26D4379ED2AAB4@exlnmb01.eur.nsroot.net> <4DF9EFD1.5010208@iup.uni-heidelberg.de> <1313780109.51443.YahooMailNeo@web111907.mail.gq1.yahoo.com> <9CD1E11E8BC9402CB4AECECAC4088443@JimPC> <1314394178.5030.YahooMailNeo@web111905.mail.gq1.yahoo.com> <1314641183.5605.YahooMailNeo@web111910.mail.gq1.yahoo.com> <4E5CBC9A.5020900@iup.uni-heidelberg.de> <1314705226.37125.YahooMailNeo@web111901.mail.gq1.yahoo.com> <4E5CF192.3040905@legal-medicine.de> <1317076720.22768.YahooMailNeo@web29509.mail.ird.yahoo.com> <1317077173.13177.YahooMailNeo@web29509.mail.ird.yahoo.com> <1317119515.35504.YahooMailNeo@web29502.mail.ird.yahoo.com> <1317119586.50531.YahooMailNeo@web29505.mail.ird.yahoo.com> In-Reply-To: <1317119586.50531.YahooMailNeo@web29505.mail.ird.yahoo.com> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: Re: My first ferrite experiments Content-Type: multipart/alternative; boundary="------------050204000105020005020107" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,HTML_MESSAGE 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: 0:2:455371616:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40854e81b8694ffb X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --------------050204000105020005020107 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay.uni-heidelberg.de id p8RBn0qb025669 Hello Daniele, Nice work and good equipment. I would suggest to make the wires between coil and cap as short as=20 possible and not to use these crocodile clamps. HF litz wire should help=20 about the Q but maybe the Q is reduced by the aluminium shield! Are the=20 rods galvanically separated from each other by a thin plastic tape? What=20 type is the ferrite material? 73, Stefan/DK7FC PS: Tell me if you need a test signal ;-) Am 27.09.2011 12:33, schrieb Daniele Tincani: > Pics 3 and 4 are attached here. > > *Da:* Daniele Tincani > *A:* "rsgb_lf_group@blacksheep.org" > *Inviato:* Marted=EC 27 Settembre 2011 12:31 > *Oggetto:* My first ferrite experiments > > Hello LF, > this evening I had some free time to spend for starting my very simple=20 > tests with ferrite rods. Picture 1 in the attached zip file shows one=20 > of the rods (about 10mm diameter x 200mm long) together with a short=20 > piece of plastic tube that I have used to adapt the rods to a=20 > larger-diameter slotted aluminium tube - shown in picture 2. As you=20 > can see, the longitudinal cut on the tube is not really regular and=20 > "clean". I'm not very good at working with metals. Nevertheless, I=20 > hope it will do the job, that is acting as a shield between the rods=20 > and the coil. Picture 3 shows two of the three rods I used, each=20 > inserted in a short piece of plastic pipe and protected with heat=20 > shrink tube and some masking tape. > Finally, picture 4 shows the very provisional setup that I used to try=20 > measuring Q of an LC pair composed by a 2-gangs variable capacitor=20 > plus a 55-turns coil wound over the aluminium tube containing the=20 > ferrite rods. I performed several measures, with 1, 2 or 3 rods inside=20 > the tube. I saw that using 3 rods increases the inductance=20 > significantly. For example, at an intermediate position of the varcap,=20 > resonance was at 1037KHz with only 1 rod inside the tube, but it was=20 > at 767 KHz with 3 rods.The Q value also increases slightly using 3=20 > rods, even thought in my tests I got only a miserable figure of about=20 > 30. Anyway, I decided to go with 3 rods for my next step, that will=20 > be to try Litz wire for the coil and see what happens. > Note: pics 3 and 4 will be attached to a re-sent of this message. > Regards > D. > > > > > > > > > --------------050204000105020005020107 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hello Daniele,

Nice work and good equipment.
I would suggest to make the wires between coil and cap as short as possible and not to use these crocodile clamps. HF litz wire should help about the Q but maybe the Q is reduced by the aluminium shield! Are the rods galvanically separated from each other by a thin plastic tape? What type is the ferrite material?

73, Stefan/DK7FC

PS: Tell me if you need a test signal ;-)

Am 27.09.2011 12:33, schrieb Daniele Tincani:
Pics 3 and 4 are attached here.
 

Da: Daniele Tincani <danieletincani@yahoo.com>
A: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
Inviato: Martedì 27 Settembre 2011 12:31
Oggetto: My first ferrite experiments

 
Hello LF,
 
this evening I had some free time to spend for starting my very simple tests with ferrite rods. Picture 1 in the attached zip file shows one of the rods (about 10mm diameter x 200mm long) together with a short piece of plastic tube that I have used to adapt the rods to a larger-diameter slotted aluminium tube - shown in picture 2. As you can see, the longitudinal cut on the tube is not really regular and "clean". I'm not very good at working with metals. Nevertheless, I hope it will do the job, that is acting as a shield between the rods and the coil. Picture 3 shows two of the three rods I used, each inserted in a short piece of plastic pipe and protected with heat shrink tube and some masking tape.
Finally, picture 4 shows the very provisional setup that I used to try measuring Q of an LC pair composed by a 2-gangs variable capacitor plus a 55-turns coil wound over the aluminium tube containing the ferrite rods. I performed several measures, with 1, 2 or 3 rods inside the tube. I saw that using 3 rods increases the inductance significantly. For example, at an intermediate position of the varcap, resonance was at 1037KHz with only 1 rod inside the tube, but it was at 767 KHz with 3 rods.The Q value also increases slightly using 3 rods, even thought in my tests I got only a miserable figure of about 30. Anyway, I  decided to go with 3 rods for my next step, that will be to try Litz wire for the coil and see what happens.
 
Note: pics 3 and 4 will be attached to a re-sent of this message.
 
Regards
D.









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