[TowerTalk] Foam cables and velocity factor

[Tom Rauch]

> 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