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LF: Re: EbNaut from Todmorden

To: <[email protected]>
Subject: LF: Re: EbNaut from Todmorden
From: "Alan Melia" <[email protected]>
Date: Mon, 7 Mar 2016 21:21:42 -0000
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Hi Paul, would your total wire length be in the range of 530m by any chance?? If so, I think the apparent length of the wire may be shorter due to the capacity to ground (it is not a free space quarterwave) If you measure the reactance (or capacitance) of just the wire a a frequency way below resonance you will a value that equates to about 6pF /m

----- Original Message ----- From: "Paul Nicholson" <[email protected]>
To: <[email protected]>
Sent: Monday, March 07, 2016 8:35 PM
Subject: LF: EbNaut from Todmorden

Today saw another 200m of wire added to the long wire antenna.

Its impedance dips to a minimum of 70 ohms at about 170kHz
corresponding to a free-space quarter wavelength of 440m which
is somewhat less than my estimated total length of wire.

100uH in series brings it into tune at about 135kHz and presents
an impedance of 50 ohms and the tuning is quite broad, I don't
think I need a variable inductance.

Can anyone advise a good frequency on which to test which
won't get in anyone's way?  I expect to be using symbols
one second or longer.

Paul Nicholson

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