Return-Path: Received: (qmail 18328 invoked from network); 20 Jul 2002 13:04:35 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 20 Jul 2002 13:04:35 -0000 Received: (qmail 27934 invoked from network); 20 Jul 2002 13:03:26 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 20 Jul 2002 13:03:25 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 17VtqR-00057T-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 20 Jul 2002 14:00:23 +0100 Received: from rhenium.btinternet.com ([194.73.73.93]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17VtqQ-00057O-00 for rsgb_lf_group@blacksheep.org; Sat, 20 Jul 2002 14:00:22 +0100 Received: from host213-1-131-17.in-addr.btopenworld.com ([213.1.131.17] helo=kitchen) by rhenium.btinternet.com with smtp (Exim 3.22 #8) id 17VtqO-0001T0-00; Sat, 20 Jul 2002 14:00:21 +0100 Message-ID: <000f01c22fed$5b513b00$118301d5@kitchen> From: "Reg Edwards" To: "LF-Group" , "Dick Rollema" Cc: "Jan Harte" , "Jaap Kroon, PA0IF" , "Klaas Robers, PA0KLS" References: <5.1.0.14.0.20020720130356.009eb780@POP3.freeler.nl> Subject: LF: Re: Calculating ERP from measured field strength Date: Sat, 20 Jul 2002 13:58:15 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Hello Dick and all, Thanks very much for your figures. I am not srprised at program predicting accuracy because attenuation is not very much different from 6dB for every doubling of distance and not much affected by type of ground. I consider +/- 3dB to be not very much where 300 km radio propagation is concerned. ;o) I have just checked the source code in program GrndWav3. It does make use of CCIR curves and data for refraction over the horizon although I have had to use some intelligent guesswork to extend to 30 MHz. It's good to be reassured I havn't introduced any bugs. What DOES surprise me is the accuracy of the group's measurements. There should be prizes given for such careful meticulous work ! When available I would be pleased to have some figures of 500 to 2000 km propagation. ======================== Regards from Reg G4FGQ Free Radio Design Software Go to http://www.g4fgq.com ======================== ---------------------------------------------------------------------------- ------- > Reg Edwards, G4FGQ, has a free program called "Grndwav3" on his web site: > www.btinternet.com/~g4fgq.regp/page3.html#S301. > > Entering Jim's EMRP=218mW and distance 329km the program predicts for the > field strength at PA0SE the following: > > Sea water: 10.35 microvolt/m > average: 8.18 microvolt/m > pastoral: 9.50 microvolt/m. > > I measured 11 microvolt/m so Reg's program can also be used when the CCIR > curves are not available. > 73, Dick, PA0SE