Three-frequency operation of the Culgoora radioheliograph

The advantages to be obtained from multifrequency operation of the Culgoora radioheliograph were appreciated during the early design phase of the original 80-MHz system and steps were taken then to facilitate the addition of other observing frequencies. The heliograph has already been converted to operate at both 80 and 160 MHz and work is well advanced to add a third frequency of 43.25 MHz. After describing the original 80-MHz system this paper outlines reasons for the choice of these frequencies and shows how the system was modified to incorporate them.