Museum of the Broadcast Television Camera

EMI 1947 CPS Emitron tube type 5954

EMI 1947 CPS Emitron tube type 5954
This tube offered several improvements over the earlier EMI Emitrons. (Iconoscope type)

The CPS Emitron tube was of the Orthicon class and the target was at the front of the tube, optically good for the lenses, and it was scanned orthogonally from the rear so no keystone distortion. The target section was 3.5 inches in diameter and the main tube 2.5 inches. It was also said that the CPS Emitron tube was free of the shading problems of the Emitron tubes.

The instability known as "peeling" was a problem for the early tubes. It was caused by a bright object in the field of view, a lamp, or bright specula reflection overloads the tube. Photographers flash bulbs were known to be a serious problem. Once a tube started to peel little could be done until normal operation could be recovered. Later cameras (1950+) had a compensation circuit to automatically reset the tube and the later CPS Emitron tubes type 5957, were free of this defect.


The CPS Emitron tube is fully described in "A review of some television pick-up tubes" by J.D. McGree. Proc I.E.E. Vol. 97 part 3 No. 50 November 1950. pages 377 to 392.


A good description is in the BBC training publication; Television Engineering, by Amos and Birkinshaw, Vols. 1, Pub. Iliffe, 1953. Pages 93-100.


    Local Index

    Page 5 of 15