Trying again.
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On 23/02/2010 at 14:16 John RABSON <[email protected]> wrote:
From: John RABSON <[email protected]>
To: [email protected]
Date: Tue, 23 Feb 2010 15:51:00 +0100
Subject: Re: LF: VLF_8.79 kHz
>My LF ground system consists of nine rods each 1 m long, separated by
>about 2 m. if I connect them in parallel the inductance at 980 Hz is
>about 7µH, and the resistance is about 25 ohms. This suggests that, at
>the frequencies we are considering, this is an essentially resistive
>termination and we don't need to cancel out the reactive part.
>
>If we place a similar setup at the other end of a long wire we should see
>of the order of 50 ohms. Given that we are working at audio frequency,
>perhaps the step-up transformer from 8 ohms could use conventional soft
>iron laminations. At 50 Hz, my colleagues used to use a rule of thumb of
>20VA per pound of laminations but I can't remember how this figure varied
>with frequency.
>
>Can any audio power engineers please comment?
>
>73
>John F5VLF
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