I live in the wonderful city of Las Vegas. I've been plumbing in Nevada for 12 years. Because of the constuction boom, most of my experience has been with new construction. Construction is as dead as a door nail right now. I started my own Service and Repair Plumbing Contracting business a little more than 2 years ago. I like to touch base on various topics relating to service work. I have been getting into line locating for copper under concrete slabs. I purchased a Navitrack and Transmitter from Ridgid. Does anyone have any advise on line locating regarding grounding the transmitter, best location to hook it up to the pipe, reccomended frequencies so as to not bleed into electrical or electrical grounding wire. You're input in this matter would be greatly appreciated. Also, any input on Fisher listening devices would be good to.