Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: EATSERVER: mailn 1166; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v02G0lmp019009 for ; Mon, 2 Jan 2017 17:00:48 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1cO4ya-0005qu-6j for rs_out_1@blacksheep.org; Mon, 02 Jan 2017 15:56:44 +0000 Received: from [195.171.43.34] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1cO4yZ-0005ql-O4 for rsgb_lf_group@blacksheep.org; Mon, 02 Jan 2017 15:56:43 +0000 Received: from porthos.netcom.co.uk ([217.72.171.73]) by relay2.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1cO4yX-0006Ov-2X for rsgb_lf_group@blacksheep.org; Mon, 02 Jan 2017 15:56:42 +0000 X-DKIM-Result: Domain=abelian.org Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=abelian.org ; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:To:Subject:Sender:Reply-To:Cc: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=kZKvpVyOOD3mI8ykB+9kKYMx0cIrxHeXIPAwBB+EFlQ=; b=oRtDbGEKqQ43721mhjsBZvpLBa E/XxkVf5jOR+JJN4DubQKxTx44pkjqEplmxGbDYWexc9jm8RT/3AIPKLxHnJPSCKoQ75r7AO3s7fN r2ZNe9bTuzPhPPw3is2jzem71yoeQaKeWJ7O2JKj6SHlbKJs1MwugZNqvK5ZdL+lEr+4=; Received: from i-194-106-52-83.freedom2surf.net ([194.106.52.83]:52352 helo=pn.abelian.org) by porthos.netcom.co.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1cO4yW-00078Y-Ax for rsgb_lf_group@blacksheep.org; Mon, 02 Jan 2017 15:56:40 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) by pn.abelian.org (Postfix) with ESMTP id 8FEFF400373 for ; Mon, 2 Jan 2017 15:56:39 +0000 (UTC) To: rsgb_lf_group@blacksheep.org References: <58625259.9060909@posteo.de> <58668A5B.1080206@posteo.de> <5866AE04.3060706@abelian.org> <586A36E3.5030704@posteo.de> From: Paul Nicholson Message-ID: <586A7837.9000101@abelian.org> Date: Mon, 2 Jan 2017 15:56:39 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <586A36E3.5030704@posteo.de> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - porthos.netcom.co.uk X-AntiAbuse: Original Domain - blacksheep.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - abelian.org X-Get-Message-Sender-Via: porthos.netcom.co.uk: authenticated_id: catchall@abelian.org X-Authenticated-Sender: porthos.netcom.co.uk: catchall@abelian.org X-Scan-Signature: f62c7cf8eeb8e5a327b71719e9bffff1 Subject: Re: VLF: Back on 5.17 kHz / 58 km... Content-Type: text/plain; charset=utf-8; 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 2.75 Status: O X-Status: X-Keywords: X-UID: 10070 Stefan wrote (28th Dec): > The wire is about 70m long and 30m above ground (average). > I can measure C ~ 480 pF. > The wire is out of stainless steel with 10mm diameter (or 12?). Stefan wrote (2nd Jan): > ant.jpg Thanks. From Google it looks like the wire length is 53m. I put the significant buildings into LCnetgen and it gives antenna capacitance 402pF with 12mm wire and 392pF with 10mm wire. I've assumed those service rooms on the roofs are 3m high. I can't find a way to make 480pF. Something wrong there. Google shows the horizontal gap between builds = 42m. As the model stands, effective height is 10.9m When you resonate the antenna with a coil, do you find that the resonant frequency agrees with 480pF antenna cap or are the resonances higher than you expect? -- Paul Nicholson