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[195.171.43.25]) by mx.google.com with ESMTP id v48si42480405eeo.41.2014.02.18.12.17.35 for ; Tue, 18 Feb 2014 12:17:36 -0800 (PST) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=fail header.i=@gmail.com; dmarc=fail (p=NONE dis=NONE) header.from=gmail.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1WFr5Q-0006xp-3A for rs_out_1@blacksheep.org; Tue, 18 Feb 2014 20:16:12 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1WFr5P-0006xg-FL for rsgb_lf_group@blacksheep.org; Tue, 18 Feb 2014 20:16:11 +0000 Received: from mail-qa0-f49.google.com ([209.85.216.49]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.77) (envelope-from ) id 1WFr5M-0002Vm-13 for rsgb_lf_group@blacksheep.org; Tue, 18 Feb 2014 20:16:10 +0000 Received: by mail-qa0-f49.google.com with SMTP id w8so23865737qac.36 for ; Tue, 18 Feb 2014 12:16:06 -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=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=WpLUlar4qI4zookqTlGZuEa+7sp8q7/8HuKWnlB0SEI=; b=suykBeKQEwXS3R8HV5Z+CS02RolKTK676cUZ3g/U9I7oJi/EoJIDGqJqVQF8GA93bL FAnlWnAQHISE58JYoWMFmT80e8aoCxlHBOeG3HBufP4tfCgBLmmkrowvpcws3f1uAm3O DjjKczJ9DEa9AMnjUqhv9UT8UszQAk/mRkb3Ex2I7Rlzr7uocCmrbtgL//8OWkSIpaEc /SbPgLYRqRc8PCdxGnCMkEjnrbAj9wdL9dEDzUDctyKkoGK8Cowcr5fYS1NOwWYUG25f CkNrtjASLeFu90nXHna8HF+ggqM4xwwW7/v0pwIkG0XnmnPm6WIacxssah8nG+UubDd3 soow== MIME-Version: 1.0 X-Received: by 10.224.67.6 with SMTP id p6mr46489091qai.6.1392754566080; Tue, 18 Feb 2014 12:16:06 -0800 (PST) Received: by 10.229.241.197 with HTTP; Tue, 18 Feb 2014 12:16:06 -0800 (PST) Date: Tue, 18 Feb 2014 20:16:06 +0000 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@yahoogroups.co.uk, "rsgb_lf_group@blacksheep.org" X-Spam-Score: -0.7 (/) 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: Since starting 474.2kHz WSPR TX with the 15m baseline earth-electrode "antenna" I have made 2 improvements: (1) Resonating the "loop" with 50-200uH of inductance, empirically to give most antenna current; (2) Adding a 4t:14t 3C90 based step-up matching transformer between the transverter and coil. Again empirically chosen to give best antenna current. This means the earth-electrodes look like several hundred ohms at this (new) QTH - quite a surprise. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.216.49 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (rogerlapthorn[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 61577e2058c0d3bf1737d7de6ed6eb16 Subject: LF: MF earth-electrode improvements Content-Type: multipart/alternative; boundary=001a11c3d24e2baf1504f2b3f19d X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE 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 --001a11c3d24e2baf1504f2b3f19d Content-Type: text/plain; charset=ISO-8859-1 Since starting 474.2kHz WSPR TX with the 15m baseline earth-electrode "antenna" I have made 2 improvements: (1) Resonating the "loop" with 50-200uH of inductance, empirically to give most antenna current; (2) Adding a 4t:14t 3C90 based step-up matching transformer between the transverter and coil. Again empirically chosen to give best antenna current. This means the earth-electrodes look like several hundred ohms at this (new) QTH - quite a surprise. My signal with G3WCB (101km) is consistently 3dB stronger today and I already have had French and Dutch spots. *Any further 474.2kHz WSPR spots would be much appreciated.* No further changes are now planned until the layout of the longer baseline, which requires help with the earth rods because of my poor health and stamina currently (stroke). The transverter runs cold, suggesting close to class E operation. 73s Roger G3XBM http://www.g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk https://sites.google.com/site/sub9khz/ http://qss2.blogspot.com/ http://www.youtube.com/user/g3xbm --001a11c3d24e2baf1504f2b3f19d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Since starting 474.2kHz WSPR TX with t= he 15m baseline earth-electrode "antenna" I have made 2 improveme= nts:

(1) Resonating the "loop" with 50-200uH of= inductance, empirically to give most antenna current;
(2) Adding a 4t:14t 3C90 based step-up matching transformer betw= een the transverter and coil. Again empirically chosen to give best antenna= current. This means the earth-electrodes look like several hundred ohms at= this (new) QTH - quite a surprise.

My signal with G3WCB=A0 (101km) is consistently 3dB stronger toda= y and I already have had French and Dutch spots.

Any= further 474.2kHz WSPR spots would be much appreciated.

No furth= er changes are now planned until the layout of the longer baseline, which r= equires help with the earth rods because of my poor health and stamina curr= ently (stroke). The transverter runs cold, suggesting close to class E oper= ation.

73s
Roger G3XBM

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