How can I find the loocation of a break in a 240V underground circuit to an outside storage building

I have an underground 240V circuit that the two hot legs are both broken, and the neutral is still intact. I have verified this with a meter. I need to find the location of the break (or burnout) so it can be repaired. I don't want to trench for a new cable because there are many other water lines and wires for a irrigation system in this area of yard. I tried a method I saw on youtube which involved using a wire connected to a lawn mower and to the underground wire and picking up signal with a portable AM radio. It works, but even thoug I had it connected to one of the broken wires, the signal bled over into the intact wire and continued to be picked up by the radio. I would like to know if anyone knows if a signal tracer available on Amazon such as the Noyafa NF-816, or something similar, would work, or would the signal bleed over through the intact wire.