Since the Silver umax is a preset machine, you'll have to modify your techniques. Hold the coil at about 2 inches off the ground THEN turn on the machine and adjust the Sensitivity to about "4" to start. You can't set the Sens. too high in highly mineralized soil; especially with a preset machine. Allow the Silver a few seconds to settle in and start hunting with s-l-o-w coil sweeps. If you can afford to get the 5.75 inch coil for your Silver, it will certainly help. As a side note, all umax coils will work on all umax machines AND they work on the DeLeon, too. That's just if you plan to add to your equipment.