The English Electric P807 also carries the alternative Type of 5820. It is a 3 inch image orthicon television camera tube.
The paper label wrapped roung the tube reads:- This tube is branded P807 but is manufactured to BBC requirements. It should, therefore, be operated and recorded as Type P809.
The image orthicon was designed in the 1940s with the objective of removing the main drawbacks in the iconoscope pick-up tube. This is an oversimplification of the development chain but in terms of practical television development is adequate.
Image Orthicons were used for broadcast quality pictures in the most expensive cameras of the 1950s and 1960s. The image orthicon has excellent detail rendering qualities.
The essential operating characteristics of the image orthicon is a low velocity scanning beam that doubles back from the target without touching it. The target is maintained at cathode potential. The beam focusing and scanning is carried out by means of electromagnetic coils around the tube. Above the base, at the right of the picture, can be seen the integral electron multiplier. A low noise signal is available as the tube's output.
The orthicon and image orthicon were both great improvements in design over the pre-WWII designs such as the Image Dissector and Iconoscope and their derivatives.
The pick-up end is 76 mm diameter and the main body is 57 mm in diameter and would slide into the associated scanning coil assembly.
The input window is optically flat.
The photosensitive layer inside the window.
Actual measured parameters of this camera tube.
Actual measured parameters of this camera tube.
The electron multiplier section and the indication that this tube has been declared as unserviceable.
The base with the spigot covering the evacuation tube.
Some of the additional connections to the head end.
Looking directly at the target.
All professional TV camera tubes were expensive precision instruments and this is the wooden box that houses and protects this exhibit.
The handle end showing the joints holding the sides to the end plates.
Inside the tube sits in the centre of the box supported by foam blocks. Additional foam blocks protect both ends.
Ready for storage.
The end window envelope is 76 mm in diameter and, excluding the B14A base pins, is 365 mm tall.
References: Data-sheet. Type P807 was first introduced in 1957. See also1957 adverts.
