A statistical method is used to segregate the quiet component from the slowly varying component of solar decimetre-wave radiation in the period 1947–54. For this purpose the radiations at frequencies 2800, 1200, and 600 Mc/s have been correlated with sunspot numbers, sunspot areas, and faculae. The mean lives of the various radiations and activities have been estimated and compared. There is an increase of life with decreasing radio frequency. The life of 2800 Mc/s radiation is about the same as sunspots but measurements of the latter show some anomalies. The slowly varying radiation flux is proportional to frequency in the range studied. The quiet sun flux has a small but significant variation with solar activity, the relative change being greater for smaller frequencies. The possibility that this variation may be associated with uncorrelated local sources, such as prominences, is not entirely excluded.