Pye Lynx CCTV Television Camera
Here is the camera with the cover removed. The mains transformer can be seen along with the scanning yoke with the vidicon tube protruding from the rear. The "valve" is a voltage stabilizer used in the power supply. It is worth noting that even "transistorised" cameras use voltages in the 400 to 750 range, can come as a surprise!

The picture was supplied by Trevor Goodenough (c)