Abstract :
Many early NICAM receivers were found to be on the point of reception failure when fed 70% eye-height signals, leaving little margin for propagation or reception antenna induced degradations. It is thought that, as with teletext, receivers should be designed to operate satisfactorily when fed with 30% eye-height signals; the best current NICAM designs fail when fed with signals of just under 50% eye-height. The causes, and cures, of eye-height reduction in various receiver designs are discussed
