Description:
<jats:p> The gravity wave detector at the University of Western Australia was based on a bending flap of [Formula: see text] tuned near the fundamental resonant frequency of a [Formula: see text] resonant-bar of [Formula: see text] at a temperature of [Formula: see text]. The displacement of the bending flap was monitored with a [Formula: see text] superconducting re-entrant cavity transducer. The performance of the transducer is related to the development of a low noise microwave pump oscillator to drive the transducer. This work studies the influence of the frequency tracking noise of Niobè. It had a burst sensitivity of [Formula: see text] with a long term operation from 1993 to early 1998. It had the lowest observed noise temperature. Using the characteristics of the detector, NIOBÈ should had reached a much better sensitivity that the one measure. It seems that the noise introduced in the system by the frequency tracking device was not taken into account at the time of operation, this noise gives a value of [Formula: see text], what is the value that limited the detector sensitivity to the one measured at the time of operation. </jats:p>