A curve showing the triple beat level required in a system for high quality performance versus the number of triple beats per channel is given in this paper. The curve is the result of subjective tests conducted at EiE in which the threshold of perceptibility of the third order intermodulation (triple beat) is observed on a TV receiver. The paper discusses the development of the curve and substantiates it by probability theory,
A table is also given which Iists from 1 to 30 channels and the number of triple beats that would be generated from these channels on the worst channel. This gives the system designer the necessary triple beat performance required to design a multichannel system.