This research deals with the dynamic response of a large flexible beam with a tip mass-pendulum system. The system is a conceptualisation of a vibration-absorbing device for large flexible structures with tip appendages. The response of the system to the wide-band random excitation is observed and analysed experimentally. The concept of the experiment is to determine the energy transfer between the beam and the pendulum due to the non-linear interaction of the modes of the system. The measurements include time history records, mean-square response curves of beam, and the pendulum for different response regimes. Also, sets of experiments were conducted to determine the autoparametric interaction between the two modes of the system in the neighbourhood of the autoparametric region. The outcome of this research reveals the scope and limitations of the beam-pendulum oscillator as a potential vibration-absorbing device in the applications where random disturbance occurs.