Are you trying to locate a specific source or just looking to see what's what? If you are tracking a problem it's most efficient to start in the middle. Don't see it where you are? Move half way toward the node and check again. You do see it? move half way toward the furthest point and check again... In other words the most efficient way is to keep dividing the distance by half.
"Quality Cable Work for Over .031 Millenium"
This is CABL.com posting #366647. Tiny Link: cabl.co/mbHxP