Analysis of magnetospheric Pc 1 and Pc 2 (in brief Pc 1--2) pulsations at a network of six northern hemisphere stations at latitudes 65¿--76¿ CGM shows that their average frequency decreases with increasing latitude of the station. Their maximum occurrence is at L=6--9 and 1200--1600 LT. The ionospheric ducting is weak for f<0.3 Hz. Occasionally the Pc 1 intensity at a station is modulated by a simultaneously arriving quasi-periodic Pc 4--5 signal. A mechanism for generating micropulsation which is common to both high-frequency and low-frequency waves is presented and discussed, the proposed mechanism being that a broadband signal from the solar wind is amplified in the magnetosphere in the frequency bands of the field line resonance (Pc 4--5) and in the He+ cyclotron frequency (Pc 1--2) range. ¿ American Geophysical Union 1996