 The telescope was used as an interferometer with the Lovell Telescope to provide more accurate positions for radio sources found from a survey done in 1972 and 1973; the position of one radio source was found to coincide with a pair of faint blue stars, and after optical observations were made it was found to be the first gravitational lens.The majority of the current observational time of the Mark II is spent either on MERLIN or VLBI observations.On 10 July 2017 the telescope was designated as a Grade I listed building.