From: "jannsen" <0482183881-0001@t-online.de>
To: rsgb_lf_group@blacksheep.org
References: <5.1.0.14.0.20020403155037.00acdf78@gemini.herts.ac.uk> <5.1.0.14.0.20020403155037.00acdf78@gemini.herts.ac.uk> <3.0.1.16.20020405160954.2c2fc068@pb623250.kuleuven.be>
Subject: Re: LF: still more loop inductance formulas
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Date: Sat, 6 Apr 2002 01:38:51 +0200
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Rik Strobbe schrieb:
> First of all my appologies to those getting bored with my loop inductance
> formulas.
> But after some 'playing' with simulation software and calcuations it turned
> out that there might be a more accurate and simpler formula to calculate
> the inductance of a big loop :
>
> L = 0.8*B*(ln(A/d)+6.82)
> where L = loop inductance in uH, A = loop height in m, B = loop length in m
> and d = wire diamater in mm
>
> At first sight there seems no (practical) limits to the A/B ratio.
>
> If this formula is correct it would also mean that (for a given height) the
> loop inductance increase linear with the loop length.
>
> 73 from a sunny Belgium (sunny and 22°C ... instead of the rain, wind and
> 10°C we usually have begin april)
>
> Rik  ON7YD
>
>
Hi Rik,

dimensions of my loop-ant: A = 12m, B = 65m, d = 4mm; 
2 turns, space 80mm (2m above ground).

I tried ur formular inserting the wirepitch somehow as multipl, 
as div, as log or ln. but the result was vy far away from 
the measured one (720uH).

any idea ?

regards
Uwe/dj8wx