control signals transmitted by fob 400 and in turn sending related signals to other appropriate tractor elements receiver 500 can be located in or near cab 120 of tractor 100 as in fig6 although preferably tractor 100 includes only one receiver 500 for receiving signals from fob 400 associated with that tractor the tractor may include more than one receiver so that different receivers may receive signals from different fobs or receive only signals concerning particular output elements receiver 500 may be of any design capable of receiving wireless signals transmitted by a fob such as fob 400 and then providing in response to the received signals related signals to appropriate elements within tractor 100 for controlling the output elements when the fob has the characteristics of fob 400 as specified above receiver 500 may have an am superheterodyne tuner e g an am superregenerative tuner for receiving signals transmitted at a frequency of approximately 319 mhz 315 mhz and a tuning range of 0 8 mhz also receiver 500 may have a near vertically polarized monopole internal trace antenna 505 see fig5 and have a frequency response of 50 khz a sensitivity of 90 dbm nom a 5 khz data rate and a range of greater than 10 meters receiver 500 may have reduced rf sensitivity for desired coverage with respect to power consumption receiver 500 may have.