Originally Posted by
ORAC
The French did come up with a couple of ideas that did go into the second GEC produced Randell and Boot magnetron design. The use of Metal Oxide coatings on the Cathode and making the Cathode a Cylinder with a separate heater element inside it. The French research was however somewhat of a collaboration between Gutton in France and Megaw at GEC. The French research allowed the British Mangetrons to work at much higher power outputs and have a much longer running life than any magnetrons built anywhere else. Randell and Boot's contribution was making the Anode block the outer case of the valve, unlike most of the other mangetron designs which had the Anode cavities as metal plates mounted within a Glass tube (The Russians and Japanese had beaten Randell and Boot as regards this feat, but Knowledge of it was not known in the UK at the time that the first British experimental model was built and run in February 1940). The Metal block Anode with the Vacuum inside it was much easier to cool than any of the Hollmann designed Magnetrons in Germany or the stuff produced by Phillips in Holland.