Marconi Instruments OA1706 Image Isocon Television Camera
Showing the removable lens and camera mounting "L" casting.

Chris Moore writes:-
Marconi Instruments made X-ray image intensifiers for medical use.The image was formed on a fluorescent screen. So that several consultants could see the image a tv camera was used to drive monitors. The cameras were image orthicon type OA1706. RCA developed the image isocon and English Electric Valve made it in England. The merits were low noise and low light perfomance. This meant a lower dose of X-rays could be used to get the same perfomance.