Return-Path: X-Spam-DCC: paranoid 1102; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id t49CTnBc012786 for ; Sat, 9 May 2015 14:29:50 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Yr3ma-0003vp-09 for rs_out_1@blacksheep.org; Sat, 09 May 2015 13:23:04 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Yr3mZ-0003vg-5O for rsgb_lf_group@blacksheep.org; Sat, 09 May 2015 13:23:03 +0100 Received: from mail-wi0-f172.google.com ([209.85.212.172]) by relay1.thorcom.net with esmtps (TLSv1.2:AES128-GCM-SHA256:128) (Exim 4.85) (envelope-from <73dk7fc@googlemail.com>) id 1Yr3mX-0002xP-6N for rsgb_lf_group@blacksheep.org; Sat, 09 May 2015 13:23:01 +0100 Received: by wief7 with SMTP id f7so53719300wie.0 for ; Sat, 09 May 2015 05:22:59 -0700 (PDT) X-DKIM-Result: Domain=googlemail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=from:message-id:date:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=S6LcjPjLXxN24H55Z7k97xJ9nIXqur9lroIFEvArE44=; b=KUbkjU2d7dzvaTaMevoaluxuj6NvheIVt0bse2xR8KEvl7i2dK6vdJNB6JKToQiySu vZEzfnMHAAIgJwRGFXkZe3gcF+CaijPTSLi9UYLj5Af0ngQBKSrNEQEz2oxe0CC06Xxi alNh+dzale4I3mD+Z8xaQE9o8mqrhQO3bQ0uI/Jn0Kfrwu1z85mQpcxZ0NMXZfnJdTWG zUPl9MpZ71xffbAV+EuZdtZoAGxv6PKLrwbluIL6wR85J8wc44AsApQJYjyXWO4Fiust pSQHtlmEGW8G7SsYEkkuGb5TVoUso0jdFuDmIgqNdHR+JTNyjvdTZVUAlEaH1Y3ZDatm 6dqw== X-Received: by 10.194.60.43 with SMTP id e11mr4893758wjr.36.1431174179174; Sat, 09 May 2015 05:22:59 -0700 (PDT) Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de. [129.206.22.206]) by mx.google.com with ESMTPSA id gs7sm3592495wib.10.2015.05.09.05.22.58 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 09 May 2015 05:22:58 -0700 (PDT) From: DK7FC <73dk7fc@googlemail.com> X-Google-Original-From: DK7FC <73dk7fc@gmail.com> Message-ID: <554DFC21.7050505@gmail.com> Date: Sat, 09 May 2015 14:22:57 +0200 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: <554CD3BD.13112.13127C0@mike.dennison.ntlworld.com> In-Reply-To: X-Scan-Signature: 7001055fa59a9c23b9831ea6d317a074 Subject: Re: LF: DK7FC VLF probe Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 3075 Hi Joe, That choke was just intended to improve the supply voltage stability (low pass filtering). It's value is not critical. Meanwhile i've learned that it can be helpful to spend a ferrite bead in front of the jFETs gate, to prevent VHF oscillations... I am one of those who prefer to spend one more component here and there, just to prevent eventual unintended behaviour... 73, Stefan Am 09.05.2015 02:44, schrieb jcraig@mun.ca: > Hi Stefan and group, > > I am building a probe using your design. Could you > explain the interstage network and the 470 uH choke? > > I hope to use this to detect some 36 km photons. So far, > using the PA0RDT miniwhip (without the VLF refit) > and Spectrum Lab has resulted in reception only of > near field electrostatic and induced artefacts > ie: my best DX is only 5.2 km. > > Best 73 & TNX > Joe VO1NA > > > > >