Time signal generating system, also known as atomic clock. Consists of 5065A Hewlett Packard rubidium vapour atomic clock, 5065A Hewlett Packard power supply, 5065A-902 Hewlett Packard sidereal time converter, audio filter by Laboratory Electronics Queensland, Yaesu FRG 7700 Communications receiver, Rola speaker, BWD 521 Oscilloscope and L.E.D. digital time display, all housed in steel cabinet with removable door. Rola speaker was Observatory stock number 361, and also used with Eddystone radio receiver (K970). Receiver filter was Observatory stock number 376.