 For several weeks, Australian signals intelligence (SIGINT) had tracked a radio transmitter from the headquarters of the 275th Regiment moving westwards to a position just north of Long Tân using radio direction finding, but extensive patrolling failed to find the unit.Provided by the top secret 547 Signals Troop, the reports began on 29 July at the height of the false alarm, with the radio detected moving towards Nui Dat from a position north of Xuyên Mộc.It continued at a rate of a day and by 13 August was located near the Nui Dat 2 feature, a hill in the vicinity of Long Tân, east of Nui Dat.