Electromagnetic interference on a transponder due to UHF set onboard a helicopter-a case study

A transponder was tested for its performance with its interrogator. The transponder and the monitoring equipment were mounted in a helicopter. The radio transmission (RT) set of the helicopter interfered with the performance of the monitoring equipment. This paper is a case study in identifying the problem and solving it. Also guidelines are suggested which if adopted would minimise the interference effect in such applications.