1.0 sin(πJt) sin(πJt)cos(πJt) sin(πJt)cs2(πJt) 0.5 00 0. 0.020 0.040 0 0.100 -0.5 J,=12 Hz; T2=1s 1.0 However, in real spin systems the size of J varies considerably, for 'JHH from ca. 1 Hz up to ca 12 Hz(or even 16-18 Hz for J and trans in olefins ). The largest passive coupling determines when the transfer function becomes zero again for the first time(e.g,12J=35 ms for J=14 Hz), and the maximum of single antiphase coherence the occurs at or shortly before ca. /4J for this coupling constant. With only one passive coupling constant and a very small active coupling, one could wait till after the first zero passing to get more intensity. However, with a large number of passive couplings of unknown size(as in most realistic cases), the only predictable maximum will occur at 20-30 Hz for most spin systems50 However, in real spin systems the size of J varies considerably, for 2, 3JHH from ca. 1 Hz up to ca. 12 Hz (or even 16-18 Hz for 2 J and 3 Jtrans in olefins). The largest passive coupling determines when the transfer function becomes zero again for the first time (e.g., 1 /2J = 35 ms for J = 14 Hz), and the maximum of single antiphase coherence the occurs at or shortly before ca. 1 /4J for this coupling constant. With only one passive coupling constant and a very small active coupling, one could wait till after the first zero passing to get more intensity. However, with a large number of passive couplings of unknown size (as in most realistic cases), the only predictable maximum will occur at 20-30 Hz for most spin systems