Return-Path: Received: from rly-de01.mx.aol.com (rly-de01.mail.aol.com [172.19.170.137]) by air-de06.mail.aol.com (v125.7) with ESMTP id MAILINDE062-4ac4ab4b8482f0; Sat, 19 Sep 2009 06:54:25 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-de01.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDE011-4ac4ab4b8482f0; Sat, 19 Sep 2009 06:54:02 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1MoxZ3-0002MO-CH for rs_out_1@blacksheep.org; Sat, 19 Sep 2009 11:53:13 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1MoxZ2-0002MD-T4 for rsgb_lf_group@blacksheep.org; Sat, 19 Sep 2009 11:53:12 +0100 Received: from mtaout01-winn.ispmail.ntl.com ([81.103.221.47]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1MoxYu-0000KV-F3 for rsgb_lf_group@blacksheep.org; Sat, 19 Sep 2009 11:53:05 +0100 Received: from know-smtpout-1.server.virginmedia.net ([62.254.123.1]) by mtaout01-winn.ispmail.ntl.com (InterMail vM.7.08.04.00 201-2186-134-20080326) with ESMTP id <20090919104755.KFGM6742.mtaout01-winn.ispmail.ntl.com@know-smtpout-1.server.virginmedia.net> for ; Sat, 19 Sep 2009 11:47:55 +0100 Received: from [82.3.250.15] (helo=jimdesk) by know-smtpout-1.server.virginmedia.net with esmtp (Exim 4.63) (envelope-from ) id 1MoxTv-0003ul-20 for rsgb_lf_group@blacksheep.org; Sat, 19 Sep 2009 11:47:55 +0100 From: "James Cowburn" To: References: <9afca2640909181501s4ea78076wf335f218ab07a106@mail.gmail.com> <9afca2640909190053uc3188c8ja0529072f1b42955@mail.gmail.com> <65021672466E4DA891D8CC98B984A4AA@JimPC> Date: Sat, 19 Sep 2009 11:47:44 +0100 Message-ID: <00d801ca3916$a172f5d0$0217aac0@jimdesk> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 11 In-Reply-To: <65021672466E4DA891D8CC98B984A4AA@JimPC> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 Thread-Index: Aco5C6ubpNe+Mnz9TtKQroMj70N8CQACqcvg X-Cloudmark-Analysis: v=1.0 c=1 a=F3M5lZpKAAAA:8 a=ocsIFUa-1G4J_5yRwNEA:9 a=JoshNq1QykR7SX_pfYMA:7 a=w38uB4creQGAIvM9fDMXxoAWjAgA:4 a=wk6s2zzMB60A:10 a=8T5nzKzCDQxmASv2:21 a=p0zuGnBRlVU0jzU4:21 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: RE: RE: 500kHz QRPp WSPR overnight Content-Type: text/plain; charset="us-ascii" 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=0.0 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 X-AOL-IP: 193.82.116.20 As I found out, relatively small improvements/changes to the system result in substantial improvements in performance. The mini VNA has been a real help in getting stuff aligned. Jim - using this formula could you estimate what my ERP is? With best regards Jim Dr. James Cowburn -----Original Message----- From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of James Moritz Sent: 19 September 2009 10:28 To: rsgb_lf_group@blacksheep.org Subject: LF: RE: 500kHz QRPp WSPR overnight 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