Return-Path: Received: (qmail 22460 invoked from network); 13 Feb 2002 14:43:04 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur-qfe1-smtp-plusnet.harl.plus.net with SMTP; 13 Feb 2002 14:43:04 -0000 Received: (qmail 20866 invoked from network); 13 Feb 2002 14:43:07 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 13 Feb 2002 14:43:07 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16b0Pr-00047S-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 13 Feb 2002 14:29:47 +0000 Received: from mta01-svc.ntlworld.com ([62.253.162.41]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16b0Pq-00047N-00 for rsgb_lf_group@blacksheep.org; Wed, 13 Feb 2002 14:29:46 +0000 Received: from oemcomputer ([213.104.105.227]) by mta01-svc.ntlworld.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with SMTP id <20020213142848.CHGI9422.mta01-svc.ntlworld.com@oemcomputer> for ; Wed, 13 Feb 2002 14:28:48 +0000 Message-ID: <000f01c1b49a$fd9ef1a0$e36968d5@oemcomputer> From: "mike.dennison" To: rsgb_lf_group@blacksheep.org References: <001a01c19a31$655db6c0$466152d5@it> <001901c1b3fc$a9ee9400$05e9fea9@g3aqc> Subject: LF: Re: Re: Vertical grounded tower for LF antenna. Date: Wed, 13 Feb 2002 14:30:30 -0000 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Giulio Scaroni wrote: But wich may be the best sistem on this tower for LF, is possible to feed directly it, may be at the top? Any idea?? G3AQC replied: I don't think there is any way to excite the tower directly.............. There is a way to excite a grounded antenna directly, that is to use a gamma match. Connect one leg of the feeder to the earth point, and the other a few metres up the mast - the higher, the better. Match this low impedance to your Tx with a transformer. Simple but effective. Mike, G3XDV [temporarily off the air whilst finding a job is occupying much of my time - but still watching the e-mails]