Billman.
I was a dealer installer for Pet Safe underground fences until the company informed me that I did not purchase enough material from them..Any way, my experience tells me to use a tiller with carbide blade and a steel blade that follows and puts the wire in right behind the blade..I know that may sound complicated, but if I can borrow my brother's digital camera I will post a picture.I usally bury the wire about an inch in the ground.Try not to get it any deeper as the signal will be lost..When I first started putting in these in, I used my garden tractor and an attachment that I made to pull behind.It worked ok, but the it was mounted rigidly on the tractor so it didn't like bumps and hills.I will try to post a picture of this also.As far as the units working, I have had my black lab on the fence for about 5 yrs now and he has never been away from home.I have about three acres enclosed and not had any problems.Just change the battery regulary and "WALLA", a dog that stays at home!!
Hoghead