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LF: Re: Ladderline C per foot?

To: <[email protected]>
Subject: LF: Re: Ladderline C per foot?
From: "James Moritz" <[email protected]>
Date: Sat, 3 Feb 2007 11:44:00 -0000
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Dear JB, LF Group,

The capacitance (per metre) of a transmission line is:

C = 1/(Zo.Vf.c)

Where Zo is characteristic impedance in ohms, Vf is the velocity factor,
which basically depends on the insulation, and c is  the speed of light (3 x
10^8 m/s). For 450ohm ladder line, velocity factor seems  to be around 0.9,
and  the above formula works out to 8.23pF/m, or as Peter says, 2.5pF per
foot.

Cheers, Jim Moritz
73 de M0BMU

----- Original Message -----
From: "J. B. Weazle McCreath" <[email protected]>
To: "LowFER at LW Cafe" <[email protected]>
Cc: <[email protected]>
Sent: Friday, February 02, 2007 10:33 PM
Subject: LF: Ladderline C per foot?


> Hello Lowfers & LFers,
>
> Does anyone on the lists happen to know the approximate
> capacity per foot of 450 ohm windowed poly ladderline?
>
> 73, J.B., VE3EAR - VE3WZL
> Solar and wind powered
> Lowfer " EAR"  188.830
> EN93dr
>
> http://www.hurontel.on.ca/~weazle
>
>
>
>



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