Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id x1460f4l031963 for ; Mon, 4 Feb 2019 07:00:42 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1gqXDg-00046y-T1 for rs_out_1@blacksheep.org; Mon, 04 Feb 2019 05:55:00 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1gqXDZ-00046n-9S for rsgb_lf_group@blacksheep.org; Mon, 04 Feb 2019 05:54:53 +0000 Received: from mail-qt1-x834.google.com ([2607:f8b0:4864:20::834]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1gqXDU-0006oq-4b for rsgb_lf_group@blacksheep.org; Mon, 04 Feb 2019 05:54:51 +0000 Received: by mail-qt1-x834.google.com with SMTP id b15so2418789qto.8 for ; Sun, 03 Feb 2019 21:54:47 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :content-transfer-encoding; bh=5NwfGc1pI17ny9Y4DKMeM37vcvHIoPuvSBCa6BsvxfM=; b=Nu9rDHeaksLnf0m8FRYvUeB2mIEJ9k1dMKoyn7ArKbhEhFSxUjAhTE+qMG+AAy+Avr DEeaAIOcLLt1AjDFuDmM/204i3RL+p7hEqEkCWfyKJu7fZRa+JtApsAL4bG+mIwir5lw pmUxmy8kUJa9XW2tzzAW+xip5f0BEhiTvqyIUSvc4te1fK8hZhPnlBPpG7u0XOWPCKXJ GSg4OEoxh8l9vvYQFuF0AfNQK9YXmBbPg9+9snZAmrRvc0qGEjJp2WKg3hj35TDkkjFW tc8R64bkg1phjq3bnUnAMqU1VnWAOtJKHdrQgN5/Vd6qhXntCpkSM2dJFKZMPyWU4cxO pdHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:content-transfer-encoding; bh=5NwfGc1pI17ny9Y4DKMeM37vcvHIoPuvSBCa6BsvxfM=; b=JSNqyHAA66pp+dH00y3FmqUGnKpVevLi/ic/PA6ijXbGOKiPF0N7A8pzCMTN+V0xUX 2d8AD+wCyF/6SFpNNhHXxE5WbyxZLtBWeSEIyr16+Ed7jWRqHfgGJHSSsTy6A5E6a0Qv l/gEFdTPbu6BQIq+pZf+0iBTI73lTVSghc1qzAniwVIqx//4OAUw/2j4M1Fk4vLrPmpZ m3Zersf9U/XHaxDi5Okp+8AztGpSQ0COEFv/tsHwFoe4mjJ5AjXENE5ccrmaUwSndH1f kySpZuGAJ6hUwDSHwu1YZdcrRQ4zQGP914A6o40kKyrwbXPEG+rNi+GaMQM060XuAInE PdEg== X-Gm-Message-State: AHQUAuaX0Ge6Item6ThzAaBZnK0q8JzcPDdvG6tpf3Fhscqw9GJV4PUK L1W23IVOHZCbXMIMrw/3Uj+mgmpMtw8YWDq3HS2qnSlz X-Google-Smtp-Source: ALg8bN7NqbbD8ofnPnF3xSneFMHCX3526WIBNF6WhpgOd1j5YqSyGNcSQlmoAa6pz+MEY610Atm+LbWnojTWZutJx0A= X-Received: by 2002:ac8:6c3:: with SMTP id j3mr38327916qth.84.1549259686436; Sun, 03 Feb 2019 21:54:46 -0800 (PST) MIME-Version: 1.0 References: <1UTCTNxG9H.5T3bfQF3xD0@optiplex980-pc> <9C9C8088-AD45-4DDF-BD7E-66D13F0D835C@md.metrocast.net> <5C4B1BD5.6010404@posteo.de> <5C51DD4B.1070205@posteo.de> In-Reply-To: From: Dimitrios Tsifakis Date: Mon, 4 Feb 2019 16:54:35 +1100 Message-ID: To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi all, I have a few mica capacitors that came from a MW broadcaster, similar to this one (in fact I have one that it bigger than this one). Stefan, I think this is probably your best bet and pity you are not closer otherwise I would be happy to lend you a couple to do your experiments :-) 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 [2607:f8b0:4864:20:0:0:0:834 listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (dtsifakis[at]gmail.com) X-Scan-Signature: c9d6a1e47761f7ec7375ac340bef30d0 Subject: Re: Re: LF: TXing WSPR/MF on an indoor loop, part 2 Content-Type: text/plain; charset="UTF-8" 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 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by klubnl.pl id x1460f4l031963 Hi all, I have a few mica capacitors that came from a MW broadcaster, similar to this one (in fact I have one that it bigger than this one). Stefan, I think this is probably your best bet and pity you are not closer otherwise I would be happy to lend you a couple to do your experiments :-) https://rustys.net.au/products/large-ducon-transmitter-honey-pot-capacitor (this is smaller than the ones I have, most are about 1 nF capacitance) 73, Dimitris VK2COW Στις Πέμ, 31 Ιαν 2019 στις 10:01 μ.μ., ο/η dhchurch έγραψε: > > Hello Dimitrios > > Polypropylene capacitors can actually self-heal to such an extent that there's little left of them. The melting point of polypropylene is not very high and they can end up as just a liitle blob of plastic. > > Don't worry though, I still use them suitably rated for the frequency in use and most of them are 600Vac or more. > > 73, Hugh, M0DSZ > > ----- Receiving the following content ----- > From: Dimitrios Tsifakis > Receiver: rsgb_lf_group > Time: 2019-01-31, 00:25:55 > Subject: Re: LF: TXing WSPR/MF on an indoor loop, part 2 > > Hi Stefan, > > In my experience these polypropylene capacitors when they fail, they > just lose some capacitance. I think they call it 'self healing', maybe > they imply that when they fail there is no short circuit? > > I have some really nice silver mica capacitors (ex MW broadcast stuff) > that would be perfect for this task... > > Anyway, I am slowly gearing up for some VLF action over here. The > other day I did some tests at 16.72 kHz into an ugly loop (very > roughly 120 metres by 3 metres, single turn) and I was able to receive > my signals using an unoptimise ferrite antenna at a bit over 2 km from > the TX. I don't think I am in the near field at that distance, am I? > :-) > > 73, Dimitris VK2COW > > > >