We present results from two long observations of XB 1746-371 by the Rossi X-ray Timing Explorer ( RXTE ) in 2002 January and May , lasting 4 and 5 days respectively .
Dips are observed in the X-ray light curves with a depth of 25 per cent , largely independent of energy within the usable band of the PCA instrument of 2.1 – 16.0 keV .
X-ray bursting and flaring activity are also evident .
The dips define the orbital period of the system , and using a power spectral analysis and a cycle counting technique we derive an accurate period of P _ { orb } =5.16 \pm 0.01 hr .
The previously-reported candidate period of 5.73 \pm 0.15 hr , obtained using Ginga data , is inconsistent with our determination , perhaps due to the weakness of the dipping and the variability of the source during that observation .
The dips in the RXTE observations presented here do not align with the Ginga period , however our improved period is consistent with a wide range of archival data .