Return-Path: Received: (qmail 5518 invoked from network); 11 Feb 2002 18:27:56 -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; 11 Feb 2002 18:27:56 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 6209 invoked from network); 11 Feb 2002 18:27:57 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 11 Feb 2002 18:27:57 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16aL7P-0006I4-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 11 Feb 2002 18:23:59 +0000 Received: from mailhost.netscapeonline.co.uk ([194.201.52.152]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16aL7N-0006Hz-00 for rsgb_lf_group@blacksheep.org; Mon, 11 Feb 2002 18:23:58 +0000 Received: from ldsas14-78-129-235.cw-visp.com ([212.137.129.235] helo=netscapeonline.co.uk) by mailhost.netscapeonline.co.uk with esmtp (Exim 3.34 #1) id 16aKvH-0005Dk-00 for rsgb_lf_group@blacksheep.org; Mon, 11 Feb 2002 18:11:28 +0000 Message-ID: <3C67F5EE.1E412AE0@netscapeonline.co.uk> Date: Mon, 11 Feb 2002 16:48:46 +0000 From: "gii3kev" Organization: Netscape Online member X-Mailer: Mozilla 4.6 [en-gb]C-CCK-MCD NetscapeOnline.co.uk (Win95; I) X-Accept-Language: en-GB,en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Vertical grounded tower for LF antenna. References: <001a01c19a31$655db6c0$466152d5@it> Content-Type: text/html; charset=windows-1252 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit  

Giulio Scaroni wrote:

Hi to all,saturday i have tested the our contest station in Mantova city in LF, and qso with G in aural CW seems not a problem with a 80 meters long vertical wire, slooping from the top of the tower, with 150 watts.But wich may be the best sistem on this tower for LF, is possible to feed directly it, may be at the top?The tower is exatly 80 meters long, with a base of 8x8 meters,

That is the type of tower that I am looking for Guilio, you should have an outstanding signal on LF with a good antenna attached to your tower. Since your tower is grounded I would use it as a support only for some inv L antennas displaced around the top of the tower and insulated from it, all vertical drop wires converging at the bottom to a loading/matching coil.
Another suggestion, use the tower again as a support for a T antenna with each horiz section as long as possible but do not let the ends get too close to ground and use a number of horiz wires if necessary all insulated from the top of the tower, with one vert drop wire.
I use the inv L configuration and it works well for me.
With a tower insulated from ground the story would be different, base fed with several horizontal long wires connected to the top of the tower, however the conductivity of the tower might be poor and lossy, the inv L
system might be the best approach.
Hope you find the info useful and thanks for the 579 report on 136 khz that you sent me last week.
de Mal/G3KEV
 
 
 
 
 
 
 
 
 
 

and at 70 meters is 1x1 meters, and at 80 meters is 0.5x0.5 meters, so big antenna with big capacitance to ground, i think is a smaller version of Decca insulated tower, but this one is grounded.Any idea??The picture is at this site http://www.as.net/~kn6dv/ik2ded/ik2ded.html 73 to all de Giulio IK2DED.