A survey of radio sources which exhibit interplanetary scintillations has been carried out with the Cambridge 18 000 m² array at 81.5 MHz. The methods of observation, and of determination of angular structure on a scale 0″.2 to 2″.0, are discussed and a catalogue lists the structure of ∼ 1500 4C sources between declinations −12° and +90°, roughly 60 per cent of which scintillate. An analysis of the results will be presented elsewhere
