Return-Path: Received: from rly-mc03.mx.aol.com (rly-mc03.mail.aol.com [172.21.164.87]) by air-mc03.mail.aol.com (v125.7) with ESMTP id MAILINMC031-d684ab4a4702dc; Sat, 19 Sep 2009 05:29:24 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mc03.mx.aol.com (v125.7) with ESMTP id MAILRELAYINMC038-d684ab4a4702dc; Sat, 19 Sep 2009 05:29:21 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1MowF5-0001Rm-1I for rs_out_1@blacksheep.org; Sat, 19 Sep 2009 10:28:31 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1MowF4-0001Rd-Hy for rsgb_lf_group@blacksheep.org; Sat, 19 Sep 2009 10:28:30 +0100 Received: from smtp827.mail.ird.yahoo.com ([217.146.189.241]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1MowDw-00067j-1d for rsgb_lf_group@blacksheep.org; Sat, 19 Sep 2009 10:27:20 +0100 Received: (qmail 80868 invoked from network); 19 Sep 2009 09:28:16 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btopenworld.com; h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:In-Reply-To:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=yzz3jOjzeaUNkZYdvEwXFk6Z75t1+U5oCQemYstUJ3tUy23gU43km94keavUgBN/sfdHnbxnEKQ6nXC+avUQU7o+/40nOSJyeSOrRBOU/aGfgcwj4fvHyBcbPQ7SNX4eEmm3G2BUDX5iIt0DcV2uylh1YjuUdbPOl1ns7uxq3Io= ; Received: from unknown (HELO JimPC) (james.moritz@86.176.84.176 with login) by smtp827.mail.ird.yahoo.com with SMTP; 19 Sep 2009 09:28:16 -0000 X-Yahoo-SMTP: qKIhhNCswBB2TTHr2BORWcGGR2mpopxhCcunGIxpCKQYiG07Q7UOhNo- X-YMail-OSG: TtQNtigVM1lVVXblVc6nnjH4ZVZmw4bqcg8rzeD7oql5W9FWXjjQ6IUaCFNVkW14hywpeIEExcUFTEYRZETMfLIxbmB9yz_v9RpB_cn0Br186iCA.zE3B0xBOkagzKTzgAVaZKryItFPFclC.521peIc1mU6QCLIx9023yC93F97x30YuoG0pFKAKTSzRuMQUqj9Gq7Rbbs6Ceu61hm2qq7zc51ae70Q3L_UtXY.hQE5dd22ucM- X-Yahoo-Newman-Property: ymail-3 Message-ID: <65021672466E4DA891D8CC98B984A4AA@JimPC> From: "James Moritz" To: References: <9afca2640909181501s4ea78076wf335f218ab07a106@mail.gmail.com> <9afca2640909190053uc3188c8ja0529072f1b42955@mail.gmail.com> In-Reply-To: <9afca2640909190053uc3188c8ja0529072f1b42955@mail.gmail.com> Date: Sat, 19 Sep 2009 10:28:13 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6001.18000 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18049 X-Karma: unknown: DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: RE: 500kHz QRPp WSPR overnight Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=MISSING_OUTLOOK_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 X-AOL-IP: 193.82.116.20 Dear Roger, LF Group, It is interesting to make an estimate of what G3XBM's ERP might be... The noise level at M0BMU during relatively quiet daytime conditions I estimate to be of the order of 3uV/m in the 2.5kHz WSPR reference bandwidth. The reported SNR gets up to about -25dB, making the signal level from G3XBM about 0.18uV/m. ERP = (Ed)^2 / 49; with E = 0.18 x 10e-6, d = 69000m , ERP is about 3uW with only "geometric spreading" propagation losses. But there is some additional reduction in field strength due to ground wave propagation losses, perhaps 3dB with "good" ground, so the ERP would then become about 6uW. Diffraction losses due to the curvature of the earth are negligible at this distance. Obviously, this could be +/- several dB due to various uncertainties, but should be of the right order of magnitude. Plenty of potential for improvement then! Cheers, Jim Moritz 73 de M0BMU