Towertalk
[Top] [All Lists]

Re: [TowerTalk] Foam cables and velocity factor

To: "Robert Chudek" <k0rc@pclink.com>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] Foam cables and velocity factor
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Fri, 11 Nov 2005 19:29:54 -0500
List-post: <mailto:towertalk@contesting.com>
> The cable wasn't rated per se. It is a foam dielectric so
I guestimated .8
> as a starting point. Can the true VF be determined from
the data I
> collected?

Sure. You can find the electrical length in feet, fractions
of a wavelength, or degrees with an analyzer and the
physical length in the same basic unit with a physical
length measurement. The measured physical length (say 100
feet or .20 wavelength) over the measured electrical length
(say something like 150 feet or .30 wavelength) would be the
actual velocity factor.

You'll find foam dielectric cables are all over the place.
Some around .90 down to near .66.

73 Tom




_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>