Return-Path: Received: (qmail 18459 invoked from network); 18 Jul 2002 10:23:56 -0000 Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 18 Jul 2002 10:23:56 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 22788 invoked from network); 18 Jul 2002 10:22:55 -0000 Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 18 Jul 2002 10:22:55 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 17V8Nt-0006tB-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 18 Jul 2002 11:19:45 +0100 Received: from mail2.cc.kuleuven.ac.be ([134.58.10.50]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17V8Ns-0006t6-00 for rsgb_lf_group@blacksheep.org; Thu, 18 Jul 2002 11:19:44 +0100 Received: from dell-rik.fys.kuleuven.ac.be ([10.33.165.177]) by mail2.cc.kuleuven.ac.be (8.12.1/8.12.1) with ESMTP id g6IAJDEc084948 for ; Thu, 18 Jul 2002 12:19:13 +0200 Message-ID: <5.1.0.14.0.20020718120508.00b95bf8@pb623250.kuleuven.be> X-Sender: pb623250@pb623250.kuleuven.be X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Thu, 18 Jul 2002 12:22:39 +0200 To: rsgb_lf_group@blacksheep.org From: "Rik Strobbe" Subject: =?UTF-8?Q?Re:_LF:_Activity_from_DLF=C2=B4s_360m_mast?= In-reply-to: <5.1.0.14.0.20020718110848.009f7960@POP3.freeler.nl> References: <003001c22c3d$9fbd3680$5f74ccd4@DEFAULT> MIME-Version: 1.0 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 At 11:17 18/07/2002 +0200, PA0SE wrote:
Dear Walter and the LF-gang,

Assuming the 360m mast has no top load my antenna simulation program gives a feedpoint impedance of
Z = 11.9 - j149 ohm over perfect ground. The reactive part depends on the diameter of the mast of course which I have arbitrarily put  at 3m.
Be sure to measure the current into the mast so the EMRP can be calculated.

quite impressing ...
That would mean than no more than 214mA antenna current would be needed to get 1W ERP. If the antenna has a +/- 50% efficiency that would mean that about 1.1W input power will do the job. The overall gain of the antenna system would be close to 0dBd, that would be 30 to 35dB better than most ham antennas.
A ham signal from the Frankfurt area is S8 with me (using a calibrated s-meter), so I guess that running a few 100W into the monster will produce S9+30dB, a nice signal but still no more than 1.6mV into 50 Ohm (I'm afraid to little to burn a lamp)
The other way arround : taking into account that 1mW ERP is sufficient to get a good QRSS signal over most of Europe it would have been interesting to run just 1mW into the big antenna during one night (in winter) a see how far that travels. A pitty that the activity will be just a few hours.

73, Rik  ON7YD