Return to KLUBNL.PL main page

[Top] [All Lists]

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
Delivered-to: [email protected]
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=s1024;; h=Received:X-YMail-OSG:Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=NOwq8tBjCv0OlP/BRYdhk/9WpKkS6cgG8VIcDLOw4T1PRp4fTvtskwIgK3wy5w9qBTxu/LnfzMBRHd3uHwmPRqlhX/WNghNb6194lgYwkl0NHvP5MDnuWxR//dIeM7G2rftFfFbxwir6VXr26WqjWbjs7gBn1Tr668Yue1ty5Ww= ;
Domainkey-status: bad (test mode)
Domainkey-status: good (testing)
References: <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
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

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

<Prev in Thread] Current Thread [Next in Thread>
  • LF: Re: Ladderline C per foot?, James Moritz <=