Return-Path: Received: from mtain-md05.r1000.mx.aol.com (mtain-md05.r1000.mx.aol.com [172.29.96.89]) by air-md07.mail.aol.com (v129.4) with ESMTP id MAILINMD074-8b8f4c3a4d7428b; Sun, 11 Jul 2010 19:02:12 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-md05.r1000.mx.aol.com (Internet Inbound) with ESMTP id D4A5138000121; Sun, 11 Jul 2010 19:02:10 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OY5Vt-00052h-Rt for rs_out_1@blacksheep.org; Mon, 12 Jul 2010 00:00:45 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OY5Vt-00052Y-55 for rsgb_lf_group@blacksheep.org; Mon, 12 Jul 2010 00:00:45 +0100 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OY5Vs-0004J2-FA for rsgb_lf_group@blacksheep.org; Mon, 12 Jul 2010 00:00:45 +0100 Received: from ix.urz.uni-heidelberg.de (cyrus-portal.urz.uni-heidelberg.de [129.206.100.176]) by relay2.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id o6BN11a1007884 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 12 Jul 2010 01:01:01 +0200 Received: from extmail.urz.uni-heidelberg.de (extmail.urz.uni-heidelberg.de [129.206.100.140]) by ix.urz.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id o6BN0hvl005840 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 12 Jul 2010 01:00:43 +0200 Received: from [129.206.196.44] (vpn044a.rzuser.uni-heidelberg.de [129.206.196.44]) by extmail.urz.uni-heidelberg.de (8.13.4/8.13.1) with ESMTP id o6BN0eF6019044 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 12 Jul 2010 01:00:40 +0200 Message-ID: <4C3A4D19.8010500@iup.uni-heidelberg.de> Date: Mon, 12 Jul 2010 01:00:41 +0200 From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.10) Gecko/20100512 Thunderbird/3.0.5 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <2E1625BBD491430EBA80E631855F5E23@df2py> <4C3A02F3.6040407@iup.uni-heidelberg.de> <640773929BA743ACA9D2703EEAC2058C@df2py> In-Reply-To: <640773929BA743ACA9D2703EEAC2058C@df2py> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: df2py @ 137.4/new match Content-Type: multipart/alternative; boundary="------------000708080702010302050101" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.7 required=5.0 tests=HTML_60_70, HTML_FONTCOLOR_UNKNOWN,HTML_MESSAGE,HTML_TITLE_EMPTY 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: 3039ac1d60594c3a4d7215f6 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --------------000708080702010302050101 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hi Wolf, Some types of audio amps have problems with reactive power. Do you really need a linear PA? Ah i suppose it is a linear PA, but in switch mode anyway? But why do you need much cooling then? A class D PA would be enough and the power dissipation is minimal! IRFP-460 is a good choice. GL es hpe cu sn! 73 de DK7FC Am 11.07.2010 22:41, schrieb Wolf Ostwald: > > Hi Stefan ! > > I just build a new amp with IRFP 460, much sturdier MosFet. But I need > lots of cooling. That killed a few black ones ( IRFP 350 ). > > And I managed to trash my 5kW NF-Amp for 9 kcs, wait for parts now. > > Same time work on coil wound on a trash-can J > > Things are being pushed here, but family and job are putting a brake > on things J, if I don't obey i`ll find myself between a rock and a > hard place J > > Keep u posted de wolf df2py > --------------000708080702010302050101 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hi Wolf,

Some types of audio amps have problems with reactive power. Do you really need a linear PA? Ah i suppose it is a linear PA, but in switch mode anyway? But why do you need much cooling then? A class D PA would be enough and the power dissipation is minimal! IRFP-460 is a good choice.

GL es hpe cu sn!

73 de DK7FC

Am 11.07.2010 22:41, schrieb Wolf Ostwald:

Hi Stefan !

I just build a new amp with IRFP 460, much sturdier MosFet. But I need lots of cooling. That killed a few black ones ( IRFP 350 ).

And I managed to trash my 5kW NF-Amp for 9 kcs, wait for parts now.

Same time work on coil wound on a trash-can J

Things are being pushed here, but family and job are putting a brake on things J, if I don’t obey i`ll find myself between a rock and a hard place J

Keep u posted  de wolf  df2py

 

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