Bet way to test a video cable?

[MrEd]

How could I test a video cable the best way to check that the impedance of the cable is still intact? For instance a video cable could be fine on an ohmic measure but let's say it has been rolled over by something heavy and the cable has been "crushed" so the capacitance in the cable is not intact where it was crushed.
Can I send a 1MHz sinewave through and check what comes out on the other side? Will that be sufficient?

MrEd

 

[cyr]

If you have a scope and pulse or step (square wave) generator you could do some simple TDR (time domain reflectormeter) measurements.

https://www.thom-tech.com/tdr.htm

 

[IanP]

TDM will show you exact spot of irregularity but if you don't have it, TDM that is, you can use 6 - 6.5MHz signal (to end of baseband video channel) and measure its attenuation. If attenuation is within the cable spec then the baseband video should also pass through ..

 

[MrEd]

Hi Guys and thanks,
I don't need to measure where the fault is, only if the cable is ok or not.
I will try to send a 6MHz sinewave through the cable with a 75ohm output and compare the amplitudes between the output and input. If they differ too much, the cable fails?
But then, when I think about it, if the cable is long the damping would be more and it would fail the test even if the cable is actually good.
So theoretically I would need to do a TDR in combination with the frequency test. The higher TDR value, the more damping I can expect ?

Is that correct?
It seems to become quite complicated to do. I hope I'm wrong