In chapter II, adds subclauses 1.3, 2.1.36, 2.4, 3.4, replaces subclauses 2.2.3, 2.2.5, 2.3.9, title of subclause 3.1 (now: linear amplifiers); in chapter III, adds subclause 5.1.12 (in section five); in chapter IV, replaces clause 18 (in section two), a