Cooperative ACTIVITY between the Army Signal Corps and Westinghouse Electric Corp. produced the special radar tube shown in the 
accompanying illustrations.  It was used in long-range detection sets,  one of which revealed the impeding attack on Pearl Harbor and another guarded the Panama Can a year before.

     Of revolutionary design, the tube produced ten times the power of uhf tubes previously built and involved manufacturing problems at first regarded as insurmountable. Besides geometrical and physical  characteristics departing radically from known techniques, the tube called for extremely difficult  copper-to-glass feather-edge seals and momentary peak currents which demanded a specially-treated tungsten filament able to withstand five times the voltages believed possible.

     The project was taken over by Westinghouse electronic engineer  Ilia E. Mouromtseff, who had, in 1933, done line-of-sight transmission work which led to the detection of automobiles passing by on the highway outside the East Pittsburgh plant of the company.  Tubes of similar construction are expected to contribute to the future advancement of f-m and television equipment.