Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dg05.r1000.mx.aol.com (Internet Inbound) with ESMTP id A0D593800008F; Sun, 7 Oct 2012 13:36:01 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TKuks-000085-KO for rs_out_1@blacksheep.org; Sun, 07 Oct 2012 18:35:06 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TKuks-00007w-7N for rsgb_lf_group@blacksheep.org; Sun, 07 Oct 2012 18:35:06 +0100 Received: from moutng.kundenserver.de ([212.227.17.9]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1TKukq-0003gP-Mu for rsgb_lf_group@blacksheep.org; Sun, 07 Oct 2012 18:35:05 +0100 Received: from [192.168.2.104] (pD9522323.dip.t-dialin.net [217.82.35.35]) by mrelayeu.kundenserver.de (node=mrbap1) with ESMTP (Nemesis) id 0M2nhO-1Te5nV0Qp4-00shTK; Sun, 07 Oct 2012 19:35:03 +0200 Message-ID: <5071BD46.3050302@legal-medicine.de> Date: Sun, 07 Oct 2012 19:35:02 +0200 From: pws User-Agent: Mozilla/5.0 (X11; Linux i686; rv:15.0) Gecko/20120825 Thunderbird/15.0 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <5070C574.4030005@iup.uni-heidelberg.de> <0C7651504C4A4734972F6FEAAB324A6A@AGB> <5071A00F.4020506@iup.uni-heidelberg.de> In-Reply-To: <5071A00F.4020506@iup.uni-heidelberg.de> X-Provags-ID: V02:K0:JKKjvSMhTNH1XUAEtpOOzaLONlg88VyctL/jBvJR2Ws fTIl0vTaeJerYCEi/xNF+yEO7wfwtaX3rErhIS0ITyNWp4X0Zk 8E8S8lntprLuP/7Tg42iAzehFgOJhGyAcMbCLHtaItFtbkkuUD PVwgYlRYhh9wEDlQhDtcMJ+vVhc1N82O8OIE9MG4pQKXVyQa/I rotO+4Frj9bLGHLtEoASQPcvLP/Ke7hyW0lqV6SbpUXWiQTDJL jBEHdnVB+sWa7tv8myWH2h0i1xHbcN/40bOOaOv0e0OcW4saUL EMp86n1AjIyYeTNchgFdTGvM4YpuD1W0PnL/GmgauNhyH0Lcms MvS2tOB0fLzvIoCKuluM= X-Spam-Score: -0.0 (/) 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: Hi Stefan, You wrote: > ... > I'm not interested in frequencies > above 600 kHz. > ... Why not trying OPs like the LT1056? Noise? The current noise levels of those devices are at some fA/sqrt(Hz) and voltage noise does not play a big role at E-Field probes. [...] Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.227.17.9 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record X-Scan-Signature: f62c7cf8eeb8e5a327b71719e9bffff1 Subject: Re: LF: GRRRRR!! Now i know... Content-Type: text/plain; charset=ISO-8859-15; 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: 3039ac1d410d5071bd802464 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi Stefan, You wrote: > ... > I'm not interested in frequencies > above 600 kHz. > ... Why not trying OPs like the LT1056? Noise? The current noise levels of those devices are at some fA/sqrt(Hz) and voltage noise does not play a big role at E-Field probes. In contrast to simple Fet or Dual-Gate MOSFet input stages I never observed any kind of IM here where "KIL" (353 kHz) is my neighbor. Furthermore using a balanced input stage like a vertical dipole, 2 x 30cm, feeding an INA111 there are much less interferences from local origin. All problems I observed using those devices are due to input limiting diodes, bad decoupling from power devices and high common mode capacitance of decoupling transformers at both ends of the feeder line. Another solution could be using 2 or 4 Fets in parallel. But doing such feeding from batteries may be problematic. I remember soldering 4 x BF981 piggybacked improved noise AND big signal handling at low frequencies. Peter, df3lp