How Can I Calculate the Velocity of Propagation for an RG58 Cable?

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~Sam~
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Homework Statement


I'm trying to calculate the velocity of propagation of a RG58 cable that is 0.5m long. It is connected to a pulse generator that passes pulses through the cable. The cable is connected to an oscilloscope, which plots the pulses. The period of the pulses are 5 microseconds apart. I have data of the max/min of the pulse, along with rise time/fall time and the FWHM. From this information I'm suppose to calculate the velocity of propagation for RG58.


Homework Equations



Not sure.


The Attempt at a Solution



It's more of a conceptual problem I'm having. I have done several calculations involving the length of the cables and the times. But when I compare that to the speed of light it is much too small.
 
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I don't see how the propagation speed can be calculated. The pulse period is whatever it is at the pulse generator, independent of the cable length or propagation speed.

One way to measure speed would be to have two cables, of different lengths, running from the generator to two separate channels of the oscilloscope. Then the time difference between the pulses on the two channels would tell you how long it takes a signal to travel the extra cable length.