Construction of the telescope was funded by the National Science Foundation, as a prototype for a planned astronomical interferometer at Owens Valley.

[1] The 40-metre (130 ft) diameter prototype was completed in 1968, but by the end of the decade plans for the interferometer were cancelled in favour of the Very Large Array.

[1] The newly-constructed prototype was instead combined with existing telescopes at Owens Valley to form a smaller interferometer, with maximum baseline of 0.75 miles (1.21 km).

[1] When operating with the Parkes telescope in Australia it provided the longest baseline then available in the world, and hence the highest angular resolution of 0.4 milliarcseconds.

As of 2018[update] the telescope takes regular measurements of over 1800 blazars, by observing each one at 15 gigahertz (2.0 cm) twice a week.