Return-Path: Received: from mtain-de10.r1000.mx.aol.com (mtain-de10.r1000.mx.aol.com [172.29.64.210]) by air-me09.mail.aol.com (v129.4) with ESMTP id MAILINME091-8bc04c03cdf8a8; Mon, 31 May 2010 10:55:52 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-de10.r1000.mx.aol.com (Internet Inbound) with ESMTP id F013538000083; Mon, 31 May 2010 10:55:49 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OJ6NU-0007ZF-Oo for rs_out_1@blacksheep.org; Mon, 31 May 2010 15:54:08 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OJ6NP-0007VE-0Y for rsgb_lf_group@blacksheep.org; Mon, 31 May 2010 15:54:03 +0100 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OJ6NM-0006vN-Ut for rsgb_lf_group@blacksheep.org; Mon, 31 May 2010 15:54:02 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay2.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id o4VErctL018443 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 31 May 2010 16:53:39 +0200 Received: from [129.206.29.99] (pc99.iup.uni-heidelberg.de [129.206.29.99]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id o4VEs0GN027461 for ; Mon, 31 May 2010 16:54:00 +0200 Message-ID: <4C03CD6E.9020906@iup.uni-heidelberg.de> Date: Mon, 31 May 2010 16:53:34 +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: <20100530.082855.1608.1.riese-k3djc@juno.com> <4C02783D.9020502@gmx.com> <4C0326F4.5050609@gmx.com> In-Reply-To: <4C0326F4.5050609@gmx.com> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: 8.97kc - TV transformer info needed Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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-sid: 3039ac1d40d24c03cdf5141b X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) Mike, Try to use just 65 % of the turns of your primary winding and i bet the optimum will be on 9 kHz! :-) 73, Stefan Am 31.05.2010 05:03, schrieb Mike.WE0H: > Well worth testing. There might be some other transformers that work > and we won't know which ones until someone tests them. Looks like 4kc > is the peak of efficiency on that transformer you tested. I found > 5.8kc is the best efficiency on my TV transformer. > > Mike > WE0H > > > > > John B wrote: >> Hi Mike, LFers, >> >> I grabbed one of my many MOTs and ran some tests with the primary >> connected to a signal generator's 600 ohm >> output and the secondary connected to a VTVM. The measured L of the >> primary is .047 H and the secondary L is >> 16 H. The turns ratio (120 Volt Primary) is 1:18 give or take a bit. >> >> With the signal generator set at 10 volts RMS, the secondary voltage >> was measured at 1 kHz. steps as below: >> >> Freq. in kHz. Sec. voltage >> >> 1 120 >> 2 150 >> 3 190 >> 4 250 >> 5 210 >> 6 160 >> 7 140 >> 8 110 >> 9 85 >> 10 60 >> >> The results are poor, just as you found Mike, so it looks like we can >> rule out using MOTs for Dreamers Band. >> It's about what one might expect from a transformer designed for 60 >> Hz. operation. >> >> 73, J.B., VE3EAR >> >> LowFER Beacon "EAR" >> 188.830 kHz. QRSS30