Temperature is another factor

[dowser]

Besides Magnet fields, Solar radiation and Electricity that can cause the atoms of the element to move creating their unique frequency, you must also consider the temperatue of signal element your using if chasing signal lines with elements. An element at 60 degrees f. and clowdy, won't signal near as far as 80 degrees and sunny. Use more sensative rods to compensate for cooler less sensative days, or charge your signal element with electricity, or heat..