On Sun, 04 Apr 2010 12:13:22 -0500, Bob wrote:

Anyone know the velocity factor of JSC #1317 450 ohm line, 18 AWG?

Hi Bob,

If you were to find a specification, it stands every chance of being
wrong. How much wrong is wholly dependant on your need for accuracy.

The answer to your question can only be effectively found at the bench
through measurements. Various reports from different reporters will
reveal a range of values because test conditions are also very
important and their variety give considerable sway. Some variation is
simply due to poor measurement technique. Some variation is a
function of production variation. Weather will contribute a
significant variation - more for ribbon line than open line.

At the end of the day, you can take an average of all such reports and
simply buy into the proposition that you have to tolerate a certain
level of indeterminacy. If you application demands precise accuracy,
then you might find you will never achieve it.

73's
Richard Clark, KB7QHC