Return-Path: Received: from mtain-dg10.r1000.mx.aol.com (mtain-dg10.r1000.mx.aol.com [172.29.65.18]) by air-de02.mail.aol.com (v126.13) with ESMTP id MAILINDE022-5ea74b5af3e435d; Sat, 23 Jan 2010 08:04:36 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dg10.r1000.mx.aol.com (Internet Inbound) with ESMTP id 6E95B380000A3; Sat, 23 Jan 2010 08:04:34 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NYfdd-0005A9-3u for rs_out_1@blacksheep.org; Sat, 23 Jan 2010 13:02:53 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NYfdc-0005A0-KN for rsgb_lf_group@blacksheep.org; Sat, 23 Jan 2010 13:02:52 +0000 Received: from mail-bw0-f221.google.com ([209.85.218.221]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NYfdZ-0002zQ-0k for rsgb_lf_group@blacksheep.org; Sat, 23 Jan 2010 13:02:52 +0000 Received: by bwz21 with SMTP id 21so1699163bwz.4 for ; Sat, 23 Jan 2010 05:02:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:date:message-id:subject :from:to:content-type; bh=WgTKLBawpoewHg6DmZdyHdRwx7B84YcikzCXXipzfZE=; b=T9tVnvuwhEZjg6K5ww+aCcq0a2QkDZyPe4B9cGUE/79RWHgbpH2LMQueg+szi1OgLZ 3lTWxJjD3j0XE3KYlg5TDlz09CRNYQ/cTWrI5a2YL4BbkyVfBHxuShgPchXahj2AlGHv RQ2xKVAMp53DzIQNgeEgzeSeOejU2m1JmhGXo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=bfMTvlogc+9AB+w24HUbERyyeDqe5AhsJYGRQroYJV3mbxOB0rUNf9pgdcw+89SgfY aMs+s6bXMEsHMYd3P06UyYs2KDG9xdxnklXOnvxiwrtgQpXDiRD+xXh6FHM4mGktKiu2 T9aL/o3V5IeHNgtjajcpIKV/Yb7Qcnu2JheS0= MIME-Version: 1.0 Received: by 10.204.49.79 with SMTP id u15mr2379273bkf.117.1264251762221; Sat, 23 Jan 2010 05:02:42 -0800 (PST) Date: Sat, 23 Jan 2010 13:02:42 +0000 Message-ID: <9afca2641001230502q45fb0825n3ee7dca1774c95eb@mail.gmail.com> From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org X-Karma: unknown: DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: G3XBM's ERP on 500kHz Content-Type: multipart/alternative; boundary=0003255543f631a2d5047dd48dfb 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=HTML_MESSAGE 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-global-disposition: G x-aol-sid: 3039ac1d41124b5af3e2441c X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0003255543f631a2d5047dd48dfb Content-Type: text/plain; charset=ISO-8859-1 All, Yesterday I did a recalculation of the G3XBM ERP based on the classic formula and re-measurements of my antenna current. My antenna is a 5m long vertical with a spiral top hat of about 7 turns about 1.5m x 1.5m. Not being clear how to model the top hat I assumed effective heights of 5, 4 or 3m. The measured antenna current is 0.12A. My results are as follows: Assumed effective height 5m ERP = 1.53mW Assumed effective height 4m ERP = 0.98mW Assumed effective height 3m ERP = 0.55mW So, I believe my 1mW ERP previously calculated is not a bad estimate, and it may indeed be *lower* than this figure. 73s Roger G3XBM -- http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/G3XBM G3XBM GQRP 1678 ISWL G11088 --0003255543f631a2d5047dd48dfb Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable All,

Yesterday I did a recalculation of the G3XBM ERP based on the= classic formula and re-measurements of my antenna current. My antenna is= a 5m long vertical with a spiral top hat of about 7 turns about 1.5m x 1.= 5m. Not being clear how to model the top hat I assumed effective heights= of 5, 4 or 3m. The measured antenna current is 0.12A.

My results are as follows:

As= sumed effective height 5m=A0=A0=A0=A0 ERP =3D 1.53mW
Assumed effective= height 4m=A0=A0=A0=A0 ERP =3D 0.98mW
Assumed effective height 3m=A0=A0= =A0=A0 ERP =3D 0.55mW

So, I believe my 1mW ERP previously calculated is not a bad estimate, and= it may indeed be lower than this figure.

73s<= br>Roger G3XBM
--

ht= tp://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/G3XBM
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088
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