The conventional analysis of distortion in a cable television system assumes that composite triple beat (CTB) accumulates on a voltage basis, which is a worst case situation. This assumption, although it may be valid for long cascades of identical devices, such as push-pull trunk amplifiers, may not be valid for feedforward trunk cascades. This is because feedforward amplifiers, which use distortion cancellation, may not be identical to other feed forward amplifiers in the cascade.
Test results for pairs of push-pull and feedforward CATV equipment are presented, as well as a theoretical analysis which explains these results.