The electric power system is continuously growing in size and complexity. Improving the reliability is a necessity and it is possible by means of continuous condition monitoring of power apparatus. Partial Discharge (PD) monitoring is one such technique that is commonly used to detect defects in power apparatus. In general, IEC 60270 based PD measurements are carried out, but in recent times antenna-based UHF measurements are gaining importance due to their advantages like continuous monitoring and non-contact detection methodology. In the current study, the antenna-based PD measurements were studied on defect models of corona discharge, surface discharge and void discharge. The PD testing was also carried out on bushings with defects. An attempt to study a new RF signal conditioning technique was also made using the Schottky diode-based power detector. Using this technique high frequency UHF signals can be shifted to lower frequencies which help reduce the bandwidth requirements for the monitoring systems thereby reducing the cost of hardware when online monitoring is carried out on a large scale.