Don't cover the device in tin foil. It'll just block the signal. The rod antenna has a coil in it at the base that picks up the signal from the small zigzag on the board. It feeds the signal to the rod and sends it on out. If you're not getting advertised range it's to be exspected. The advertised range is under ideal condistions. In the real world figure 3/4 to 1/2 that range.