"Bob F" wrote in message
. ..
My father has a underground wire to a panel in his garage from his house.
One lead of the 220V service has apparently "opened" somewhere
underground. It is probably about 100 feet long.

I'd love to trace the break so I can dig it up next time I visit. We
suspect that a splice was made in the wire someplace that may have failed.

Can anyone offer any good ideas for a way to locate the break without
digging the whole thing up? Maybe something using a transister radio as a
locator and a relay buzzer or something as a signal source.

Bob




Not exactly homebrew, but a "time domain reflectometer" will do the job.
It's a piece of highly specialized equipment.

http://en.wikipedia.org/wiki/Time-domain_reflectometer