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=-2.1 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO,HTML_50_60,HTML_MESSAGE 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 t4KGcpGN029246 for ; Wed, 20 May 2015 18:38:51 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Yv6xL-0000dL-RD for rs_out_1@blacksheep.org; Wed, 20 May 2015 17:34:55 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Yv6xL-0000dC-FU for rsgb_lf_group@blacksheep.org; Wed, 20 May 2015 17:34:55 +0100 Received: from s16315160.onlinehome-server.info ([87.106.80.234] helo=mail.vigilant.es) by relay1.thorcom.net with esmtp (Exim 4.85) (envelope-from ) id 1Yv6xJ-0005F1-EY for rsgb_lf_group@blacksheep.org; Wed, 20 May 2015 17:34:54 +0100 Received: from servigilant.vigilant.local ([87.216.178.132]) by vigilant.es with MailEnable ESMTP; Wed, 20 May 2015 18:34:36 +0200 Received: from servigilant.vigilant.local ([fe80::3cdf:95f8:c1c9:3931]) by servigilant.vigilant.local ([fe80::3cdf:95f8:c1c9:3931%17]) with mapi id 14.03.0123.003; Wed, 20 May 2015 18:34:37 +0200 From: =?iso-8859-1?Q?VIGILANT_Luis_Fern=E1ndez?= To: "rsgb_lf_group@blacksheep.org" Thread-Topic: LF: EA5DOM vertical Thread-Index: AQHQkv2qN1kkoNK9xUCh1aDO+HggJJ2FBB0g Date: Wed, 20 May 2015 16:34:36 +0000 Message-ID: <579355A36AEE9D4FA555C45D556003AB1B1075E9@servigilant.vigilant.local> In-Reply-To: <555C85D8.7080702@posteo.de> Accept-Language: es-ES, en-US Content-Language: es-ES X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [192.168.0.2] MIME-Version: 1.0 X-Scan-Signature: f9f85a03ab18710b130c40acc03380f0 Subject: RE: LF: EA5DOM vertical Content-Type: multipart/alternative; boundary="_000_579355A36AEE9D4FA555C45D556003AB1B1075E9servigilantvigi_" 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: 3176 --_000_579355A36AEE9D4FA555C45D556003AB1B1075E9servigilantvigi_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Stefan Thank you for your detailed explanations I can recycle 16cm diameter PVC tube. As seen in the calculators and assumi= ng a copper wire with plastic cover to be 3mm diameter can wind 300 turns in 90cm lenght which would be 2.33 mH. That can be a sta= rting point and the coil should be attached to the bottom support of the vertical antenna. See and old picture here showing the setup https://dl.dropboxusercontent.com/u/7162072/Fotos%20varias/29-03-2011/DSC03= 912.JPG May be 5pF/m is the standard assumption for a vertical antenna against hori= zontal ground plane. But here the counter poise will be different and probably showing much less capacity. I can use a high voltage capacitor= in parallel with the coil to tune. The variable capacitor I'm already using with the loop, for example. Would it make the trick to use a = smaller coil ?? You can also use a spark gap in parallel to the coil. I have done the same = here on my antenna Frightening ! But if the spark is boxed into a red lantern will be also use= ful as visual beacon for aeroplanes :-))) 73 de Luis EA5DOM ________________________________ De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blackshe= ep.org] En nombre de DK7FC Enviado el: mi=E9rcoles, 20 de mayo de 2015 15:02 Para: rsgb_lf_group@blacksheep.org Asunto: Re: LF: EA5DOM vertical Hi Luis, I changed the subject of the discussion. Am 20.05.2015 14:34, schrieb VIGILANT Luis Fern=E1ndez: Hi Stefan Which is the turn count on your variometer ?? I can count about 10 in the i= nternal 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 =3D 2.04 mH There are many coil calculators in the web. I recommend such a simple singl= e 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 als= o start with a smaller coil, maybe 10 cm diameter and enamelled cu wire. Th= is 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 differen= ce. You can also use a spark gap in parallel to the coil. I have done the s= ame here on my antenna, see https://dl.dropboxusercontent.com/u/19882028/LF= /20111106-19h58m31s-FF7_8466.jpg 73, Stefan --_000_579355A36AEE9D4FA555C45D556003AB1B1075E9servigilantvigi_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Stefan
 
Thank you for your detailed expla= nations
I can recycle 16cm diam= eter PVC tube. As seen in the calculators and assuming a copper wire with p= lastic cover to be 3mm diameter
can wind 300 turns in 90cm lenght= which would be 2.33 mH. That can be a starting point and the coil sho= uld be attached to the bottom support
of the vertical antenna. See and = old picture here showing the setup
 
May be 5pF/m is the standard assu= mption for a vertical antenna against horizontal ground plane. But here the= counter poise will be different
and probably showing much less ca= pacity. I can use a high voltage capacitor in parallel with the coil to tun= e. The variable capacitor I'm
already using with the loop, for = example. Would it make the trick to use a smaller coil ??
 
You can = also use a spark gap in parallel to the coil. I have done the same here on = my antenna
 
Frightening ! But if the spark is boxed into a red= lantern will be also useful as visual beacon for aeroplanes :-)))
 
73 de Luis
EA5DOM


De: owner-rsgb_lf_group@blacksheep.= org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de DK7FC
Enviado el: mi=E9rcoles, 20 de mayo de 2015 15:02
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: LF: EA5DOM vertical

Hi Luis,

I changed the subject of the discussion.

Am 20.05.2015 14:34, schrieb VIGILANT Luis Fern=E1ndez:
Hi Stefan
&= nbsp;
Which is the turn count on your v= ariometer ?? I can count about 10 in the internal coil but how many&nb= sp;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 =3D 2.04 mH
There are many coil calculators in the web. I recommend such a simple singl= e 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 t= est
Sure, at least for first experiments you can use a normal coil. You can als= o start with a smaller coil, maybe 10 cm diameter and enamelled cu wire. Th= is 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 Frankl= in lighthing arrestor of the building ! :-(
If the building is 80m high, your 11m vertical will not make a big differen= ce. You can also use a spark gap in parallel to the coil. I have done the s= ame here on my antenna, see https://dl.dropboxusercontent.com/u/19882028/LF/20111106-19h58m31s-FF7_8466= .jpg


73, Stefan
--_000_579355A36AEE9D4FA555C45D556003AB1B1075E9servigilantvigi_--