Return-Path: Received: (qmail 25027 invoked from network); 19 Dec 2002 14:06:28 -0000 Received: from netmail02.services.quay.plus.net (212.159.14.221) by mailstore with SMTP; 19 Dec 2002 14:06:28 -0000 Received: (qmail 27207 invoked from network); 19 Dec 2002 14:06:24 -0000 Received: from post.thorcom.com (193.82.116.70) by netmail02.services.quay.plus.net with SMTP; 19 Dec 2002 14:06:24 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18P1J5-0007LL-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 19 Dec 2002 14:05:47 +0000 Received: from [62.253.164.43] (helo=mta3-svc.business.ntl.com) by post.thorcom.com with esmtp (Exim 4.10) id 18P1J5-0007LB-00 for rsgb_lf_group@blacksheep.org; Thu, 19 Dec 2002 14:05:47 +0000 Received: from l8p8y6 ([62.252.228.213]) by mta3-svc.business.ntl.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with SMTP id <20021219140542.JAEY15439.mta3-svc.business.ntl.com@l8p8y6> for ; Thu, 19 Dec 2002 14:05:42 +0000 Message-ID: <004901c2a767$acd4ea20$15e9fc3e@l8p8y6> From: "hamilton mal" To: rsgb_lf_group@blacksheep.org References: <004001c2a6c8$8c75de00$74e9fc3e@l8p8y6> <001401c2a6d9$13882a00$482965d5@oemcomputer> <000e01c2a6db$0d7f7260$09dc9384@jka> Date: Thu, 19 Dec 2002 10:32:07 -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: Re: Re: jason etc Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=0.0 required=5.0tests=DATE_IN_PAST_03_06,QUOTED_EMAIL_TEXT,REFERENCES, SPAM_PHRASE_00_01,USER_AGENT_OEversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group ----- Original Message ----- From: "John Andrews" To: Sent: Wednesday, December 18, 2002 9:18 PM Subject: LF: Re: Re: jason etc > > and a similar antenna at the receiving end instead of small loops or 3 > feet active type antennas. > > Just curious -- since the signal to noise ratio in my receiving installation > appears to be limited by external (man-made and atmospheric) noise, rather > than noise in my preamp/receiver, how would a 100 foot tower improve that > situation? In my case the 120 ft vertical top loaded system, comprising 4 inv L structures resonated on 136 khz is a good 12 db better at receiving signals than my 90 metre perimiter loop resonated also on 136 khz and top wire height 70 ft. I am comparing signals from the loop in its optimum direction. E/W. Both systems are configured for 50 ohms match to the RX. I live out in the countryside and noise is not a problem. Some are getting confused and discussing the merits of a vertical against a loop in noisy or Urban environments. I am discussing the two antennas in a noise friendly area, and as someone has pointed out loops also pick up quite a lot of noise depending on your location. The only loop worth while is a full wave loop at the frequency of operation, the smaller you get in relation to natural resonance the less the capture ability and more critical the tuning, and going off resonance with the slightest movement by wind, rain etc, so it is seldom optimum at the required frequency except you happen to live in Dixie or Texas where the sun always shines!! 73 de Mal/G3KEV > > John Andrews, W1TAG > >