Detecting Length (Getting creative)

Hi everyone,
I would like to use Arduino for a project to try determine a cable's length.
The concept is to use this device(s) to try assist in determining where a short is in an electrical fence.

My initial idea, was to have two devices, one which sends a signal and the other which receives it and either display's a value or plays an audible sound to depict the distance between the two devices.

I was hoping to implement a system which allows the sensitivity/strength of the signal to be modified on site.

Initially my idea was to mimic a "tone detector" and use the "quality of the signal" to try determine the distance between the two devices.

Any ideas on how I can accomplish this while using the arduino platform?

J

What length are you talking about ? 10 meter, 100, 1000 10000?

IIRC the device your looking for is a - Time-domain reflectometer - Wikipedia -

discussed among others here