Abstract: A system comprising one or more interior antenna(s) positioned within an at least partially enclosed operator area of a human operated machine and one or more exterior antenna(s) positioned on an external portion of the human operated machine, with a radio frequency shield positioned between the interior antenna(s) and the exterior antenna(s), is usable with a processing module electrically connected with the antennas for analyzing signals received from the antennas to determine whether a radio frequency generating device is active within the at least partially enclosed operator area.