  Recent CHIME/FRB observations of the periodic repeating FRB 180916B have
produced a homogeneous sample of 44 bursts. These permit a redetermination of
the modulation period and phase window, in agreement with earlier results. If
the periodicity results from the precession of an accretion disc, in analogy
with those of Her X-1, SS 433, and many other superorbital periods, the width
of the observable phase window indicates that the disc axis jitters by an angle
of about 0.14 of the inclination angle, similar to the ratio of 0.14 in the
well-observed jittering jet source SS 433.
