Postal tracking system

摘要: A system for tracking mail bags, letters, and parcels through a post office to determine processing times accurately as well delays is disclosed. An unobtrusive transponder in the form of card located letters or bags be tracked. number stations are along route irradiate these bags. Each station includes an array three antennas disposed mutually orthogonal relationship so notwithstanding its position. When irradiated by ultra high frequency (UHF) energy, activated transmits VHF signal. The transmitting circuit which may selectively set transmit signal having uniquely identifying transponder. receiver plurality transponders providing output when if tracked it passes each route.