Return-Path: Received: from rly-md02.mx.aol.com (rly-md02.mail.aol.com [172.20.29.140]) by air-md06.mail.aol.com (v125.7) with ESMTP id MAILINMD063-8e94acdea18378; Thu, 08 Oct 2009 09:33:40 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-md02.mx.aol.com (v125.7) with ESMTP id MAILRELAYINMD021-8e94acdea18378; Thu, 08 Oct 2009 09:33:14 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Mvt6E-0004AP-MY for rs_out_1@blacksheep.org; Thu, 08 Oct 2009 14:32:06 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Mvt6D-0004AG-Vh for rsgb_lf_group@blacksheep.org; Thu, 08 Oct 2009 14:32:06 +0100 Received: from smtp5.freeserve.com ([193.252.22.151] helo=smtp6.freeserve.com) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Mvt62-00066g-60 for rsgb_lf_group@blacksheep.org; Thu, 08 Oct 2009 14:31:56 +0100 Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3531.me.freeserve.com (SMTP Server) with ESMTP id F39151C00081 for ; Thu, 8 Oct 2009 15:31:44 +0200 (CEST) Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3531.me.freeserve.com (SMTP Server) with ESMTP id E66D71C00085 for ; Thu, 8 Oct 2009 15:31:44 +0200 (CEST) Received: from AGB (unknown [91.109.9.74]) by mwinf3531.me.freeserve.com (SMTP Server) with SMTP id 4084C1C00081 for ; Thu, 8 Oct 2009 15:31:42 +0200 (CEST) X-ME-UUID: 20091008133142264.4084C1C00081@mwinf3531.me.freeserve.com Message-ID: <51CAC7DA7A3043F9BBDE6535A7B0F79B@AGB> From: "Graham" To: References: <1034F871DB99454AB819054B51F39B19@IBM7FFA209F07C> In-Reply-To: <1034F871DB99454AB819054B51F39B19@IBM7FFA209F07C> Date: Thu, 8 Oct 2009 14:31:41 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8064.206 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8064.206 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: ERP at LF Content-Type: multipart/alternative; boundary="----=_NextPart_000_002F_01CA4824.0D4E0580" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30,HTML_MESSAGE, 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 ------=_NextPart_000_002F_01CA4824.0D4E0580 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To Quote from over the pond :-=20 He ... insists that no mathematical formula, however exact it may appe= ar to be, can be of greater accuracy than the assumptions on which it= is based, and he draws the conclusion that experience still remains= the great teacher and final judge. - James Kip Finch Luckily the regulation body's use the same desire guide lines that= 'we' do , so every one is happy .... apart from those who insist on= working to 6 place's of decimals from measurements taken with a ex= RAF ww2 Ae currant meter ...=20 Antennas are a dark art , formulate behind closed doors with the math= s to follow , at Lf we seem to have geology to contend with as well= , surely a constant, but then again , i'm not a geologist , so I ca= n only guess , so therefore its ok to make a guess about things we= 'don't know' about ...but that assumes we know about everything else= .. ? I don't see it as a 'problem' as such, a reasonable amount = of work has been done, the results of which are published and are= accepted as 'fit for purpose'=20 G ..=20 From: Chris=20 Sent: Thursday, October 08, 2009 10:32 AM To: RSGB LF Group=20 Subject: LF: ERP at LF Seems to me that measuring ERP at LF is a bit of a problem. On here I= have read comments referring to a stations ERP by various operators= : 'Estimate', 'Guess', 'Approx.', 'Reckon I'm fairly close to...', 'A= pproaching' etc. Nobody REALLY knows exactly! Even Mike's book, 'LF To= day - A guide to success on 136kHz', refers to certain 'estimates' hav= ing to be made. The last sentence on the bottom of p81 just about sums= it up. I don't know what the answer is, but it is clear that ERP at LF is far= more complex than at VHF/UHF etc. where 'full size' antennas are gene= rally used. Chris, G4AYT. ----------------------------------------------------------------------= ---------- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 8.5.421 / Virus Database: 270.14.7/2422 - Release Date: 10/08= /09 06:39:00 ------=_NextPart_000_002F_01CA4824.0D4E0580 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
To Quote  from ov= er the pond :-=20
 
He ... insists that no= mathematical=20 formula, however exact it may appear to be, can be of greater accuracy= than the=20 assumptions on which it is based, and he draws the conclusion that exp= erience=20 still remains the great teacher and final judge.
-=20 James Kip Finch
Luckily the  regulation body= 's use the=20 same  desire guide lines that 'we' do , so every one = is happy=20 .... apart from those who insist on working to  6 place's of = ;=20 decimals  from measurements taken with a ex RAF ww2  &n= bsp;Ae=20 currant meter ...
 
Antennas are a dark art , formula= te behind=20 closed doors with the  maths to  follow  , at Lf we see= m to =20 have geology to contend with as well  , surely a  constant,= but then=20 again , i'm not a geologist , so I can only  guess  , so&nbs= p;=20 therefore its ok to  make a guess about things we 'don't know' ab= out ...but=20 that assumes we know about everything else ..   ?=20 I don't see  it as a= 'problem' as=20 such, a reasonable amount  of work has been done, the  resul= ts=20 of  which are  published and are accepted as  'fit for= purpose'=20
 
G ..

From: Chris
Sent: Thursday, October 08, 2009 10:32 AM
Subject: LF: ERP at LF

Seems to me that measuring ERP at LF= is a bit of a=20 problem. On here I have read comments referring to a stations ERP by= various=20 operators : 'Estimate', 'Guess', 'Approx.', 'Reckon I'm fairly cl= ose=20 to...', 'Approaching' etc. Nobody REALLY knows exactly! Even Mike's bo= ok, 'LF=20 Today - A guide to success on 136kHz', refers to certain 'estimates'= having to=20 be made. The last sentence on the bottom of p81 just about sums it=20 up.
I don't know what the answer is, but= it is clear=20 that ERP at LF is far more complex than at VHF/UHF etc. where 'full si= ze'=20 antennas are generally used.
Chris, G4AYT.


No virus found in this incoming message.
Checked by AVG= -=20 www.avg.com
Version: 8.5.421 / Virus Database: 270.14.7/2422 - Rel= ease Date:=20 10/08/09 06:39:00
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