On February 17 and 21-22, 1950, two
exceptionally large radio-frequency disturbances of solar origin were observed
on seven radio receivers working in the frequency range from 62 to 9400 Mc/s.
At each of the frequencies the radio-frequency power flux was recorded
continuously during the disturbance and at several frequencies the polarization
of the radiation was examined. The apparent position of the origin of the
radiation was determined at one frequency.
The time of commencement and the duration
of the disturbances at the different frequencies were compared with each other
and with those of associated phenomena, solar flares, radio fade-outs, and
geomagnetic effects. The two disturbances show marked similarities and marked
differences ; these are summarized.