His father was Mungo Lorenz MacCallum, a Rhodes Scholar,[2] barrister and journalist, and son of Dorette and Mungo William MacCallum, Chancellor of the University of Sydney.

SALT was popular throughout the armed forces and was valued also by many Australian officials and war correspondents.

[4] After the end of the War and the closure of SALT (1946), MacCallum worked for several years as a columnist with the Sun, a Sydney tabloid newspaper, before joining the ABC in 1952.

After a stint at the BBC, he helped produce the first night of television in Australia in 1956.

[5] His books included two novels, Voyage of Love, and Son of Mars, and a memoir, Plankton's Luck.