Return-Path: Received: (qmail 7556 invoked from network); 21 Jul 2002 10:16:52 -0000 Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 21 Jul 2002 10:16:52 -0000 Received: (qmail 6069 invoked from network); 21 Jul 2002 10:16:15 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 21 Jul 2002 10:16:15 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 17WDiM-0007HK-00 for rsgb_lf_group-outgoing@blacksheep.org; Sun, 21 Jul 2002 11:13:22 +0100 Received: from cmailenv3.svr.pol.co.uk ([213.218.77.55]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17WDiM-0007HF-00 for rsgb_lf_group@blacksheep.org; Sun, 21 Jul 2002 11:13:22 +0100 Received: from [62.21.130.56] (helo=w8k3f0.freeler.nl) by cmailENV3.svr.pol.co.uk with esmtp (Exim 3.35 #1) id 17WDiK-00086e-00; Sun, 21 Jul 2002 10:13:20 +0000 Message-ID: <5.1.0.14.0.20020721095922.00a05170@POP3.freeler.nl> X-Sender: FRE0000086604@POP3.freeler.nl X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Sun, 21 Jul 2002 10:04:51 +0200 To: "Reg Edwards" From: "Dick Rollema" Subject: LF: Re: Calculating ERP from measured field strength Cc: "LF-Group" , "Dick Rollema" , "Jan Harte" , "Jaap Kroon, PA0IF" , "Klaas Robers, PA0KLS" In-reply-to: <000f01c22fed$5b513b00$118301d5@kitchen> References: <5.1.0.14.0.20020720130356.009eb780@POP3.freeler.nl> MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit To All from PA0SE

Reg Edwards, G4FGQ, wrote:

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.

CCIR Recommendation 368-7 contains curves for frequencies from 10kHz up to and including 30MHz.

When available I would be pleased to have some figures of 500 to 2000 km
propagation.

There are indications that at distances over 1000km or so even at daytime some sky wave may be present, disturbing the measurement. The sky wave will be weak of course, but so will be the ground wave.

73, Dick, PA0SE