Delivered-To: daveyxm@virginmedia.com Received: by 10.50.93.2 with SMTP id cq2csp22893igb; Fri, 30 Aug 2013 01:08:31 -0700 (PDT) X-Received: by 10.194.94.10 with SMTP id cy10mr22687wjb.66.1377850109871; Fri, 30 Aug 2013 01:08:29 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id fa19si798634wid.70.1969.12.31.16.00.00; Fri, 30 Aug 2013 01:08:29 -0700 (PDT) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1VFJAH-0001MP-Fh for rs_out_1@blacksheep.org; Fri, 30 Aug 2013 08:30:41 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1VFJAG-0001MG-I0 for rsgb_lf_group@blacksheep.org; Fri, 30 Aug 2013 08:30:40 +0100 Received: from rhcavuit01.kulnet.kuleuven.be ([134.58.240.129] helo=cavuit01.kulnet.kuleuven.be) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1VFJAE-00012c-GC for rsgb_lf_group@blacksheep.org; Fri, 30 Aug 2013 08:30:39 +0100 X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-KULeuven-Scanned: Found to be clean X-KULeuven-ID: C160E20007.A5497 X-KULeuven-Information: Katholieke Universiteit Leuven Received: from icts-p-smtps-1.cc.kuleuven.be (icts-p-smtps-1e.kulnet.kuleuven.be [134.58.240.33]) by cavuit01.kulnet.kuleuven.be (Postfix) with ESMTP id C160E20007; Fri, 30 Aug 2013 09:30:27 +0200 (CEST) Received: from ICTS-S-HUB4.luna.kuleuven.be (icts-s-hub4.luna.kuleuven.be [10.112.9.18]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by icts-p-smtps-1.cc.kuleuven.be (Postfix) with ESMTPS id BE2264042; Fri, 30 Aug 2013 09:30:27 +0200 (CEST) Received: from ICTS-S-MBX1.luna.kuleuven.be ([fe80::edaf:341f:90e:f70e]) by ICTS-S-HUB4.luna.kuleuven.be ([fe80::c11b:83f0:c46c:c366%26]) with mapi id 14.02.0328.009; Fri, 30 Aug 2013 09:30:21 +0200 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" , "rsgb_lf_group@yahoogroups.co.uk" Thread-Topic: iron powder toroid cores Thread-Index: Ac6lUIT4DYwUt5T1TK64PwAautLaTw== Date: Fri, 30 Aug 2013 07:30:20 +0000 Message-ID: <7E7DFBB4D102A04DB5ADC88D66628A4A0FC368A8@ICTS-S-MBX1.luna.kuleuven.be> Accept-Language: nl-BE, en-US Content-Language: nl-BE X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.112.13.13] MIME-Version: 1.0 X-HELO-Warning: Remote host 134.58.240.129 (rhcavuit01.kulnet.kuleuven.be) used invalid HELO/EHLO cavuit01.kulnet.kuleuven.be - verification failed X-Spam-Score: -2.8 (--) 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: Dear all, I intend to replace the air coils in the LPF on my 475 kHz transmitter by toroid core coils. I have a stock of T200-2 cores but for the power level want to get (500W would be required to get near the 5 W EIRP limit) one T200-2 is just on the edge in regard with the maximum flux (and thus temperature rise. [...] Content analysis details: (-2.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [134.58.240.129 listed in list.dnswl.org] -2.1 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 42bbe44aa18353e845a65753486d556c Subject: LF: iron powder toroid cores Content-Type: multipart/alternative; boundary="_000_7E7DFBB4D102A04DB5ADC88D66628A4A0FC368A8ICTSSMBX1lunaku_" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_40_50,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 Status: O X-Status: X-Keywords: X-UID: 1272 --_000_7E7DFBB4D102A04DB5ADC88D66628A4A0FC368A8ICTSSMBX1lunaku_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear all, I intend to replace the air coils in the LPF on my 475 kHz transmitter by t= oroid core coils. I have a stock of T200-2 cores but for the power level wa= nt to get (500W would be required to get near the 5 W EIRP limit) one T200= -2 is just on the edge in regard with the maximum flux (and thus temperatur= e rise. To be on the save side I would use 2 T200-2 toroids for each coil, and ther= e are 2 options: 1. Glue 2 cores together to make one core of the double height. This would reduce the flux to 70%, well under the limit. It would also redu= ce the number of windings to 70%, but due to the double coil height the wir= e length will increase slightly (abt. 10%). But as the cores have rounded egdes there wil be some air space between the= wire an the core, what might increase loss. 2. Put 2 toroid core coils, each of half the inductance, in series. This will also reduce the flux to 70%, but the total wire length needed wil= l increase by abt. 40%. In option 1 I will need lees wire (=3D less loss) compared to option 1, but= the air space might undo this advantage. So my question is: what will be best? All advice is welcome. 73, Rik ON7YD - OR7T --_000_7E7DFBB4D102A04DB5ADC88D66628A4A0FC368A8ICTSSMBX1lunaku_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dear all,

 

I intend to replace the air coils in= the LPF on my 475 kHz transmitter = ;by toroid core coils. I have a stock of T20= 0-2 cores but for the power leve= l want to get (500W would be required to = ;get near the 5 W EIRP limit)  one=  T200-2 is just on the edge= in regard with the maximum flux (and t= hus temperature rise.

To be on the save side I would<= a> use 2 T200-2 toroids for=  each coil, and there are 2 options:

 

1. Glue 2 cores together to mak= e one core of the double height.

This would reduce the flux to 70%, w= ell under the limit. It would&nb= sp;also reduce the number of windings to 70%, but due to the double coil height the wire length will increase slightly (abt. 10%).

But as the cores have rounded e= gdes there wil be some air = space between the wire an the co= re, what might increase loss.

 

2. Put 2 toroid core coils, each of half = the inductance, in series.

This will also reduce the flu= x to 70%, but the total wire lengt= h needed will increase by abt. 40%.

 

In option 1 I will need le= es wire (=3D less loss) compared to&nbs= p;option 1, but the air space might<= /a> undo this advantage.

 

So my question is: what = will be best?

All advice is welcome.

 

73, Rik  ON7YD - OR7T

 

--_000_7E7DFBB4D102A04DB5ADC88D66628A4A0FC368A8ICTSSMBX1lunaku_--