Return-Path: Received: (qmail 25336 invoked from network); 19 Oct 2003 13:15:15 -0000 Received: from unknown (HELO murphys.services.quay.plus.net) (212.159.14.225) by mailstore with SMTP; 19 Oct 2003 13:15:15 -0000 Received: (qmail 7155 invoked from network); 19 Oct 2003 13:15:08 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from post.thorcom.com (193.82.116.20) by murphys.services.quay.plus.net with SMTP; 19 Oct 2003 13:15:03 -0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ABDJQ-0004l9-Dq for rsgb_lf_group-outgoing@blacksheep.org; Sun, 19 Oct 2003 14:09:36 +0100 Received: from [62.253.164.48] (helo=mta8-svc.business.ntl.com) by post.thorcom.com with esmtp (Exim 4.14) id 1ABDJP-0004l0-KM for rsgb_lf_group@blacksheep.org; Sun, 19 Oct 2003 14:09:35 +0100 X-Fake-Domain: l8p8y6 Received: from l8p8y6 ([62.252.228.200]) by mta8-svc.business.ntl.com (InterMail vM.4.01.03.37 201-229-121-137-20020806) with SMTP id <20031019130934.TOSA21010.mta8-svc.business.ntl.com@l8p8y6> for ; Sun, 19 Oct 2003 14:09:34 +0100 X-Bad-Message-ID: no DNS (l8p8y6) Message-ID: <000201c39639$a74dc560$c8e4fc3e@l8p8y6> From: "hamilton mal" To: rsgb_lf_group@blacksheep.org References: <000c01c3957f$fbe6d4a0$47cdfc3e@l8p8y6> <000f01c395cc$88ece780$045bfea9@RSGB613192> Date: Sun, 19 Oct 2003 08:47:13 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: Re: 136 khz LF Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.2 required=5.0 tests=DATE_IN_PAST_03_06,HTML_40_50,HTML_MESSAGE autolearn=no version=2.60 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Spam-Rating: 2 Content-transfer-encoding: 8bit
 
----- Original Message -----
Sent: Sunday, October 19, 2003 12:06 AM
Subject: LF: Re: 136 khz LF

You can't possibly mean -5dBm.
 
Even if propagation were line of sight, at 200km distance (near enough between you ?)  Free space loss = 32.4+20LOG(f.d)  [MHz, km]  = 61dB.   EIRP max 30dBm so max power received assuming you antenna were 100% efficient (!!!!)  could only be -31dBm.
 
I don't think there can be a propgation mechnism at these freqs where path loss can be less than line-of-sight.  Unlike ducting on microwave paths.
 
Using speclab this is what was indicated. Nothing calibrated. Relative measurement signal above noise floor 55 db.
I expect to be really meaningful the system needs to be calibrated. Next time I will try the calibrated LEVEL METER
The signal was very strong, likwise M0BMU is also very strong. Large dog bones across the screen !!!!!!
 
Andy  G4JNT
----- Original Message -----
Sent: Saturday, October 18, 2003 2:58 PM
Subject: LF: 136 khz LF

Band quiet today at my observation times. Did see G3YXM on QRS very strong signal at -5 dbm and 55 db signal above noise floor.
73 de Mal/G3KEV