[TenTec] 75 Ohm twin velocity factor ?

[Steve Hunt]

Folks,

Thanks for all the responses on the Velocity Factor issue.

I would expect 75 Ohm twin to have a lower VF than 300 Ohm or 450 Ohm line. With nothing but air between the conductors the limit on characteristic impedance is 83 Ohms, so to achieve 75 Ohm the line must have a significant amount of dielectric material as a separator; this will tend to lower the VF.

I have an MFJ259B and ZM30 so I could measure it easily enough if I had some. Being a "cheapskate" I didn't want to go buying it before knowing it would do what I want. I guess I'll just have to buy a few metres to test :)

Thanks again.

Steve G3TXQ