Return-Path: Received: (qmail 13150 invoked from network); 28 Dec 2003 18:33:43 -0000 Received: from unknown (HELO ptb-mxscan01.plus.net) (212.159.14.235) by ptb-mailstore01.plus.net with SMTP; 28 Dec 2003 18:33:43 -0000 Received: (qmail 84853 invoked from network); 28 Dec 2003 18:33:43 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore01.plus.net (212.159.14.215) by ptb-mxscan01.plus.net with SMTP; 28 Dec 2003 18:33:42 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (Exim) id 1AafjR-000Lxm-QV for dave@picks.force9.co.uk; Sun, 28 Dec 2003 18:33:41 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Aafj1-0001HE-GK for rs_out@blacksheep.org; Sun, 28 Dec 2003 18:33:15 +0000 Received: from [62.253.164.42] (helo=mta2-svc.business.ntl.com) by post.thorcom.com with esmtp (Exim 4.14) id 1Aafiw-0001Gp-7r for rsgb_lf_group@blacksheep.org; Sun, 28 Dec 2003 18:33:10 +0000 X-Fake-Domain: l8p8y6 Received: from l8p8y6 ([62.252.206.13]) by mta2-svc.business.ntl.com (InterMail vM.4.01.03.37 201-229-121-137-20020806) with SMTP id <20031228183308.PADB19255.mta2-svc.business.ntl.com@l8p8y6> for ; Sun, 28 Dec 2003 18:33:08 +0000 X-Bad-Message-ID: no DNS (l8p8y6) Message-ID: <000101c3cd6d$6ee77de0$0dcefc3e@l8p8y6> From: "hamilton mal" To: rsgb_lf_group@blacksheep.org References: <6.0.1.1.2.20031227144750.035a8d70@POP3.freeler.nl> Date: Sun, 28 Dec 2003 18:04:36 -0000 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: "T" versus "L"aerial 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-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,HTML_FONT_BIG,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: rs_out@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SPAMFiltered: yes X-Spam-Rating: 2 Content-transfer-encoding: 8bit

----- Original Message -----

From: Dick Rollema

To: LF-Group

Sent: Saturday, December 27, 2003 2:09 PM

Subject: LF: "T" versus "L"aerial

To All from PA0SE

Further to my e-mail of 26 December I measured the field strength as radiated by the aerial in
Inverted L-configuration. From this I found EMRP = 57 milliwatt.

This confirms the benificial effect of top loading. The T-aerial radiated 140 milliwatt.

So going from a single 20m top load wire for the "L" to 2 x 20m for the "T" resulted in an improvement by a factor 2.46 (3.9dB) in radiated power.

The vertical part of the "T" consisted of an open wire feedline of 11m with the two wires connected in parallel in the attic shack. For the "L" one of the feedline wires was removed. I assume this did not appreciably affect the EMRP.

HI Dick

From your explanation using open wire feeder you are using an inv L with one feeder wire connected and with the 2 feeders strapped at the shack end then you have two inverted L antennas in parallel. A true T antenna has both feeder wires connected at the top as well as the bottom, in fact do not use open wire feeder, connect one wire to the centre of your T horizontal at the top and the bottom of your single wire to the loading coil and matching unit.

73 de Mal/G3KEV

.

73, Dick, PA0SE