Radio Noise Meter Response to Random Pulses by Computer Simulation

The radio interference from high voltage transmission lines is generally measured using either the CISPR or the ANSI type of instrument to give the quasipeak value and in some cases also the peak and average values, of the interference. However, because of the random and uncorrelated nature of corona generation on the transmission lines, the analysis of radio interference propagation can be made only in terms of rms quantities. In order to resolve this apparent inconsistency between the measurement and analysis of radio interference, the response of the conventional radio noise meters to random pulses is investigated using digital computer simulation. Some results are verified using a hybrid computer simulation, which represents more closely the detector output circuit of a radio noise meter. The results show that as the degree of randomness, both in amplitudes and separation intervals, of the pulses increases, the quasi-peak value becomes roughly proportional to the rms value. It is also shown that it is possible to predict, even with greater accuracy, the rms response of the radio noise meter from the measured quasi-peak and average responses.