DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
  s=s1024; d=btinternet.com;
  h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE;
  b=kuvGcnJdHtLFLovSUn2xLxguKumY68ATvXZoHeB4rst5x7US3pn6ZXYtdykEo0Cdlq3AL3Oy3IfAkd64hAKw08ka2nZwAvGrjCzbmu+iYQPrAfbyjHlkVGVdFiZA8ZNXoufIf3EfLK0MECSTY1zNCZdcIgWF4TwLFlvzfR28b8c=  ;
Message-ID: <B7F9CFF13CA248319AC32C9CA777B7D0@lindavideo>
From: "Ken" <ken.h.wright@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
References: <4BAF2B2D.1010300@dsl.pipex.com>
Date: Sun, 28 Mar 2010 20:39:31 +0100
MIME-Version: 1.0
DomainKey-Status: good (testing) 
Subject: LF: Re: Antenna Matching 500kHz
Content-Type: text/plain;
	format=flowed;
	charset="iso-8859-1";
	reply-type=response
Content-Transfer-Encoding: 7bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


Hi Tim.
Iuse my 102ft doublet with 8m of 430 ohm feeder as a 'T' antenna loaded with 
a variometer, and an earthing system of 36 radials of varing length in a 270 
degree pattern. The variometer consists of :

Outer winding  26 + 26 turns 140mm dia 16/0.2 wire,  giving 313uH

Inner Rotor 34 + 34 turns 40mm dia 16/0.2 wire, giving 84uH.

I have connected the rotor winding in series with the two outer windings at 
their centre point, this may not be the best position but it suited my 
construction and it works ok. The TX is running 23W into a 50 ohm dummy 
load, and the peak antenna current is about 900mA, ERP approx 100mW.
I hope this is of use to you.
73
Ken.
M0KHW      IO91TV




----- Original Message ----- 
From: "tim hague" <m0afj@dsl.pipex.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Sunday, March 28, 2010 11:10 AM
Subject: LF: Antenna Matching


> I'm just about to apply for my 500kHz NoV, I've got around 100W of Tx 
> power available and I'm looking for some information on antenna matching, 
> my Tx antenna is just going to be a 132ft Marconi T with a 50ft vertical 
> section, can I get away with just a series tuned matching cct or are the 
> voltages across my matching C going to be very high, I have a wide spaced 
> C approx 200 to 700pF.
>
> Thanks  Tim M0AFJ
>