Velocity of propagation

A signal takes a certain amount of time to get from the input to the output of an electronic line. The length of the line and the speed of propagation of an electrical wave determine the transit time of a signal frequency (often specified in the data sheet).

L = vp x tp

Cable length = L Propagation
Velocity = vp
Phase delay = tp

Here is an example of the different propagation speeds:
Speed ​​of light in free space = 300,000 km / s (approx.)
Overhead lines = 280,000 km / s (approx.)
Speed ​​of propagation in the cable = 30,000 km / s

The speed of propagation (vp) is the transmission speed of the electrical energy in the cable, expressed in [%] the speed of light in free space. The speed of propagation is influenced, among other things, by twisting the central conductor and braiding the outer conductor.