Return-Path: X-Spam-DCC: paranoid 1290; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_50_60,HTML_MESSAGE,RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id t4KD4uFB028617 for ; Wed, 20 May 2015 15:04:56 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Yv3dc-0008HT-7m for rs_out_1@blacksheep.org; Wed, 20 May 2015 14:02:20 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Yv3db-0008HK-U3 for rsgb_lf_group@blacksheep.org; Wed, 20 May 2015 14:02:19 +0100 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.85) (envelope-from ) id 1Yv3da-0004RI-44 for rsgb_lf_group@blacksheep.org; Wed, 20 May 2015 14:02:18 +0100 Received: from crusoe.iup.uni-heidelberg.de (crusoe.iup.uni-heidelberg.de [129.206.22.248]) by relay2.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id t4KD2HMu015228 for ; Wed, 20 May 2015 15:02:17 +0200 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by crusoe.iup.uni-heidelberg.de (Postfix) with ESMTP id F1417E1B5E for ; Wed, 20 May 2015 15:02:16 +0200 (CEST) Message-ID: <555C85D8.7080702@posteo.de> Date: Wed, 20 May 2015 15:02:16 +0200 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <579355A36AEE9D4FA555C45D556003AB1B107392@servigilant.vigilant.local> In-Reply-To: <579355A36AEE9D4FA555C45D556003AB1B107392@servigilant.vigilant.local> X-Scan-Signature: 5934134de2d93cab1d5fc440b67de82f Subject: Re: LF: EA5DOM vertical Content-Type: multipart/alternative; boundary="------------090208030303030509030405" X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 3171 This is a multi-part message in MIME format. --------------090208030303030509030405 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Hi Luis, I changed the subject of the discussion. Am 20.05.2015 14:34, schrieb VIGILANT Luis Fernández: > Hi Stefan > Which is the turn count on your variometer ?? I can count about 10 in > the internal coil but how many in the outer coil ? I don't know more than one can see on the image. My coil dimensions are not relevant for you, just the principal configuration. You can assume to have 5 pF/m, i.e. about 55 pF for your vertical antenna. So for 475 kHz you will need L = 2.04 mH There are many coil calculators in the web. I recommend such a simple single layer coil. No need to spend to much effort here. > May be a variometer is not needed as I can adjust the lenght of the > antenna. Althought loosing lenght (height) is never an advantage > a fixed coil would simplify the test Sure, at least for first experiments you can use a normal coil. You can also start with a smaller coil, maybe 10 cm diameter and enamelled cu wire. This is quickly done. But do not use ferrite or iron powder cores! It must be an air coil. Reducing the antenna height is not a good idea :-) > One of the reasons to avoid using the vertical Ae hardwired to GND via > coil is not to become the Franklin lighthing arrestor of the building > ! :-( If the building is 80m high, your 11m vertical will not make a big difference. You can also use a spark gap in parallel to the coil. I have done the same here on my antenna, see https://dl.dropboxusercontent.com/u/19882028/LF/20111106-19h58m31s-FF7_8466.jpg 73, Stefan --------------090208030303030509030405 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hi Luis,

I changed the subject of the discussion.

Am 20.05.2015 14:34, schrieb VIGILANT Luis Fernández:
Hi Stefan
 
Which is the turn count on your variometer ?? I can count about 10 in the internal coil but how many in the outer coil ?
I don't know more than one can see on the image. My coil dimensions are not relevant for you, just the principal configuration.
You can assume to have 5 pF/m, i.e. about 55 pF for your vertical antenna. So for 475 kHz you will need L = 2.04 mH
There are many coil calculators in the web. I recommend such a simple single layer coil. No need to spend to much effort here.

May be a variometer is not needed as I can adjust the lenght of the antenna. Althought loosing lenght (height) is never an advantage
a fixed coil would simplify the test
Sure, at least for first experiments you can use a normal coil. You can also start with a smaller coil, maybe 10 cm diameter and enamelled cu wire. This is quickly done. But do not use ferrite or iron powder cores! It must be an air coil.
Reducing the antenna height is not a good idea :-)

One of the reasons to avoid using the vertical Ae hardwired to GND via coil is not to become the Franklin lighthing arrestor of the building ! :-(
If the building is 80m high, your 11m vertical will not make a big difference. You can also use a spark gap in parallel to the coil. I have done the same here on my antenna, see https://dl.dropboxusercontent.com/u/19882028/LF/20111106-19h58m31s-FF7_8466.jpg


73, Stefan
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