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Message-ID: <D7944DB38D574B3F80ED328092378310@JimPC>
From: "James Moritz" <james.moritz@btopenworld.com>
To: <rsgb_lf_group@blacksheep.org>
References: <Pine.LNX.3.95.1100301013359.218A-100000@noname.nodomain.nowhere> <34EE45A0413B499D9FD2861D88BD4AE1@AGB>
In-Reply-To: <34EE45A0413B499D9FD2861D88BD4AE1@AGB>
Date: Mon, 1 Mar 2010 20:58:34 -0000
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Subject: Re: LF: 9kHz without high voltage
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Dear Graham, LF Group,

Well, scaling the 12 inch diameter coil on 160m would require about a 60 
metre diameter coil at 9kHz, so still quite "challenging". It would need an 
impressive no-entry sign too ;-)

I think you are referring to the toroidal antennas invented by Prof. Roger 
Jennison (G2AJV - now sadly SK). There is an article at 
http://www.physics.princeton.edu/~mcdonald/examples/EM/jennison_cq_23_summer_95.pdf
and many others.

Cheers, Jim Moritz
73 de M0BMU

----- Original Message ----- 
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: Monday, March 01, 2010 7:56 PM
Subject: Re: LF: 9kHz without high voltage


> Making  a   Torodial  antenna, as  presented at the  Egham HFC  would be a 
> good  start ..