  The Parkes-Tidbinbilla took advantage of a real-time radio-link connecting
the Parkes and Tidbinbilla antennas to form the world's longest real-time
interferometer, perhaps the earliest example of eVLBI. Built on a minuscule
budget, it was an extraordinarily successful instrument, generating some 24
journal papers including 3 Nature papers, as well as facilitating the early
development of the Australia Telescope Compact Array. Here we describe its
origins, construction, successes, and life cycle, and discuss the future use of
single-baseline interferometers in the era of SKA and its pathfinders.
