Tool for locating underground Cat 5?

Hey,

Typical toners like the Fluke MicroScanner are not sensitive enough to locate buried Cat 5 (which makes sense, that's not the intention of the device). Has anyone used found a reliable tool for this? The goal is to locate a Cat 5 cable underground, and both sides of the cable are accessible (so I have the ability to connect both the toner and a receiver on the other end).

Thanks!