|Marconi MkIV Television Camera 45° view|
The Marconi MkIV camera was exceptionally well built and had many well thought out features. Part of the design objectives was that after warm up and alignment it would be stable enought to be operated continuously with only adjustments to the iris and lift, even in difficult outside broadcast conditions. The construction was of lightweight castings and aluminum panels. A crank handle operates a lead screw mechanism to raise the front of the camera so that the Image Orthicon tube could be changed. The replacement of Image Orthicon tubes was always problematic due to the size of the tube and access. Most of the electronics were on printed circuit boards which were strengthened with metal mounting frames. All the valves were on the PCB's except some of the larger octal ones used for the line scanning circuits. A servo motor in the large housing in the middle of the turret drove the irises of the four lenses through the quadrant gear rings. The camera cable used was either BICC Mk4b or BIW TV-33 standard.