Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-de03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4BBFF38000095; Mon, 16 Jan 2012 18:44:45 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RmwD6-0003ah-UJ for rs_out_1@blacksheep.org; Mon, 16 Jan 2012 23:43:32 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RmwD6-0003aY-6n for rsgb_lf_group@blacksheep.org; Mon, 16 Jan 2012 23:43:32 +0000 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RmwD5-0006sv-CW for rsgb_lf_group@blacksheep.org; Mon, 16 Jan 2012 23:43:32 +0000 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 q0GNhTYa018506 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 17 Jan 2012 00:43:29 +0100 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 q0GNhTJf025962 for ; Tue, 17 Jan 2012 00:43:29 +0100 Message-ID: <4F14B612.2080009@iup.uni-heidelberg.de> Date: Tue, 17 Jan 2012 00:43:14 +0100 From: =?ISO-8859-15?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 X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: LF: Beacon to the west... / TA Content-Type: multipart/alternative; boundary="------------070502000702000807050305" 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=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: 1:2:398057696:93952408 X-AOL-SCOLL-URL_COUNT: 1 x-aol-sid: 3039ac1d40cb4f14b66d18a3 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --------------070502000702000807050305 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Hello LF group, After a break of 2 days on LF, which is VERY long for me, i am back on about 136.172. I've done various changes on the circuit and even use another VFO (the DDS is used in the first VLF experiments). It is running on batteries and i just opened the windows to the shack so there may be a little drift. I'm back with -3 dB f.s. and its frozen outside! :-) This is the last pair (4 pcs.) of FETs and i will go back to the IRFP460 then. However i found there is also a IRFP460A which looks a bit more suitable for such critical switch mode applications. I've already ordered 20 pcs of them ;-) The FETs i'm using right now have rise and fall times below 10 ns which may be even worse in this application. But maybe the actual reason why they blow up is a completely different. Thus i will test the DDS now (no phase glitches)... If someone wants to report about the signal, it is welcome :-) 73, Stefan/DK7FC --------------070502000702000807050305 Content-Type: text/html; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Hello LF group,

After a break of 2 days on LF, which is VERY long for me, i am back on about 136.172. I've done various changes on the circuit and even use another VFO (the DDS is used in the first VLF experiments). It is running on batteries and i just opened the windows to the shack so there may be a little drift.
I'm back with -3 dB f.s. and its frozen outside! :-)
This is the last pair (4 pcs.) of FETs and i will go back to the IRFP460 then. However i found there is also a IRFP460A which looks a bit more suitable for such critical switch mode applications. I've already ordered 20 pcs of them ;-) The FETs i'm using right now have rise and fall times below 10 ns which may be even worse in this application. But maybe the actual reason why they blow up is a completely different. Thus i will test the DDS now (no phase glitches)...

If someone wants to report about the signal, it is welcome :-)

73, Stefan/DK7FC


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