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Date: Wed, 1 Aug 2007 14:59:42 +0100 (BST)
From: John GM4SLV <gm4slv@sighthound.demon.co.uk>
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Subject: Re: LF: Re: Re: newbie help
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Rog,

That's an interesting idea - I've never thought of trying a digital Cap 
meter. I must try it on the new antenna - and compare it to my homebrew 
RF bridge, calculations and - more telling - to the valuse of L I 
eventually need to resonate it.


John GM4SLV


On Wed, 1 Aug 2007, GW3UEP wrote:

> Re ant cap: you can use a DMM [Rapid 328] to gnd - I use 1000pF across 
> its terminals to decouple RF for a stable reading. Simply subtract its 
> value. 73, Rog.
> 
> ----- Original Message ----- 
> From: James Moritz 
> To: rsgb_lf_group@blacksheep.org 
> Sent: Wednesday, August 01, 2007 12:05 PM
> Subject: LF: Re: newbie help
> 
> 
> Dear Paul,
> 
> In a nutshell:
> 
> - You can tune up more or less any bit of wire for reasonable results 
> on 500kHz. For best results, make it as high up as possible, and 
> secondarily as long as possible. An HF long wire, or dipole with 
> feeders strapped would be fine.
> 
> -Work out the capacitance of the wire (see formulas on ON7YD's 
> antennas pages). and calculate the inductance for resonance around 
> 502.5kHz. For most HF-sized wire antennas, this will be of the order 
> of 100s of uH. The resulting coil is