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 w7DIwxWH024582 for ; Mon, 13 Aug 2018 20:59:02 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1fpHy4-0004dV-Mk for rs_out_1@blacksheep.org; Mon, 13 Aug 2018 19:53:28 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1fpHy4-0004dM-0q for rsgb_lf_group@blacksheep.org; Mon, 13 Aug 2018 19:53:28 +0100 Received: from esa01.ucs.mun.ca ([134.153.136.21]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1fpHy2-00024o-9a for rsgb_lf_group@blacksheep.org; Mon, 13 Aug 2018 19:53:26 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A2HHBQBy0nFb/5nomYZcHgEGDINOgWK?= =?us-ascii?q?YW4FoJYF2lg4LKwGEQAKDSiE4FAECAQEBAQEBAgICaSiFOQEEATgCMgoDBQs?= =?us-ascii?q?LNBJXBoUsCK1iiBmCN4ZRgkMXggCBRYJfhEoYEYVhAogHklcJj1SOOIY8jFW?= =?us-ascii?q?BWCKBUoQqkGsmgSsBAYwFAQE?= X-IPAS-Result: =?us-ascii?q?A2HHBQBy0nFb/5nomYZcHgEGDINOgWKYW4FoJYF2lg4LK?= =?us-ascii?q?wGEQAKDSiE4FAECAQEBAQEBAgICaSiFOQEEATgCMgoDBQsLNBJXBoUsCK1ii?= =?us-ascii?q?BmCN4ZRgkMXggCBRYJfhEoYEYVhAogHklcJj1SOOIY8jFWBWCKBUoQqkGsmg?= =?us-ascii?q?SsBAYwFAQE?= X-IronPort-AV: E=Sophos;i="5.53,234,1531794600"; d="scan'208";a="4088211" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from plato.ucs.mun.ca ([134.153.232.153]) by smtp01.ucs.mun.ca with ESMTP/TLS/DHE-RSA-AES256-SHA; 13 Aug 2018 16:23:22 -0330 Date: Mon, 13 Aug 2018 16:23:20 -0230 (NDT) From: jcraig@mun.ca X-X-Sender: jcraig@plato.ucs.mun.ca To: Roelof Bakker cc: rsgb_lf_group@blacksheep.org In-Reply-To: <5B3B6AF9.4461.1370B03@roelof.ndb.demon.nl> Message-ID: References: , <5B38A763.17452.850587@roelof.ndb.demon.nl>, <5B3B6AF9.4461.1370B03@roelof.ndb.demon.nl> MIME-Version: 1.0 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 @@CONTACT_ADDRESS@@ for details. Content preview: Hi Roelof, I compared the original miniwhip with the new eco version (single SMT J310, 10Meg across the gate) and initially found it much noisier. The problem was inadequate bypass capacitance for the cold end of T1, the input xfmr for the SM6LKM converter, which I was using to provide a bias current for the eco mw. Although the original mw has perhaps 5-10 dB more gain, this can be offset by attaching a 30 cm wire to antenna of the eco mw. It was very gratifying to hear DFC-39 while sitting in the living room with the eco whip in my hand. [...] Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: 1708620d3ce65bee0beaaede7929769a Subject: Re: LF: SAQ Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.3 required=5.0 tests=NO_REAL_NAME 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 Hi Roelof, I compared the original miniwhip with the new eco version (single SMT J310, 10Meg across the gate) and initially found it much noisier. The problem was inadequate bypass capacitance for the cold end of T1, the input xfmr for the SM6LKM converter, which I was using to provide a bias current for the eco mw. Although the original mw has perhaps 5-10 dB more gain, this can be offset by attaching a 30 cm wire to antenna of the eco mw. It was very gratifying to hear DFC-39 while sitting in the living room with the eco whip in my hand. It is an effective and simple design which draws less power than the original mw. This means it will have less of a global warming impact. Thanks for the design, Roelof. Johan's VLF converter also works very well including VLF. The LO is 10 MHz and the primary of T1 is 5 mH. I have been testing it without the diplexer and it seems fine -- leaving me to wonder if it is worth the effort install a diplexer. 73 Joe VO1NA On Tue, 3 Jul 2018, Roelof Bakker wrote: > Hello Joe, > > The design is slightly different. > I use now 2 J310's parallel and Rs = 560 ohm. > Supply voltage can be anything between 4 and 20 V, whilst the current draw is 7 mA. > > The output transformer is wound bifilar on a FT-37-43 with 20 turns, but a high mu toroid will > work equally well. A BN-73-202 binocular core with 10 bifilar turns can also be used. > > VLF performance can be enhanced by increasing the 1M gate resistor to 10M or higher. > > 73, > Roelof, pa0rdt > > >