. The Bell System technical journal . ablished by prewar television. Two general types ofcathode-ray tubes have been commonly employed in the military radarprogram, electrostatic and magnetic, these classifications being indicative ofthe deflection and focussing method employed. Electrostatic Deflection Type A typical form of electrostatic-type of cathode-ray tube suitable for radarindicator purposes is shown in Fig. 38. In this tube type the electronsemitted from an indirectly heated cathode surface are initially formed intoa beam by passage through an aperture which serves as a beam density
. The Bell System technical journal . ablished by prewar television. Two general types ofcathode-ray tubes have been commonly employed in the military radarprogram, electrostatic and magnetic, these classifications being indicative ofthe deflection and focussing method employed. Electrostatic Deflection Type A typical form of electrostatic-type of cathode-ray tube suitable for radarindicator purposes is shown in Fig. 38. In this tube type the electronsemitted from an indirectly heated cathode surface are initially formed intoa beam by passage through an aperture which serves as a beam density orultimate brightness control element. Following this, the electrons proceedthrough another aperture which is maintained at a positive potential withrespect to the cathode. This first anode together with the following secondanode forms an electron lens system which focuses the beam on the fluores- ELECTRONGUN V, ICATHODE_[ HEATER CONTROLGRID SECONDANODE DEFLECTION PLATES:VERTICAL HORIZONTAL FLUORESCENTSCREEN ji y ^ FIRSTFOCUSINGANODE. HIGH-VOLTAGE ,^AUXILIARY ANODE II j i ANOUb I Fig. 38.—Schematic diagram of an electrostatic type cathode-ray tube. cent screen surface. The relative potentials of these elements serve toenable focussing of the beam by electrical means. The deflection of thebeam for scanning purposes is here accomplished by the introduction of anelectric field formed by the application of potential across the deflectionplates shown. Two pairs of plates enable separate horizontal and verticaldeflection to be employed. The plates are formed as shown to enable ob-taining the maximum deflection per unit of electrical potential applied with-out interference with the beam under large deflection conditions. Thehigh-voltage auxiliary anode is provided in certain tube types to furtheraccelerate the beam after deflection without an appreciable reduction ofdeflection sensitivity and results in an image of increased brightness. To realize optimum performance of an electrost
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
