. The Bell System technical journal . ze an increase in the filamentemission is possible only by an impractical and unwarranted increasein the filament heating current. VACUUM TUBES AS HIGH-FREQUENCY OSCILLATORS 111 The logical extension of these principles to increasingly high fre-quencies requires the use of closer and closer inter-electrode mechanical difficulties are encountered. Curiously enoughthe limiting factor in the power dissipating ability of the tube turnsout to be the grid temperature rather than the temperature of the plateas might be expected. This comes about b
. The Bell System technical journal . ze an increase in the filamentemission is possible only by an impractical and unwarranted increasein the filament heating current. VACUUM TUBES AS HIGH-FREQUENCY OSCILLATORS 111 The logical extension of these principles to increasingly high fre-quencies requires the use of closer and closer inter-electrode mechanical difficulties are encountered. Curiously enoughthe limiting factor in the power dissipating ability of the tube turnsout to be the grid temperature rather than the temperature of the plateas might be expected. This comes about because of the required closegrid-filament spacing, and makes necessary the adoption of somemethod of cooling the grid. One of the writers has constructed a seriesof tubes in which the grid is a tungsten helix, each turn of which isattached to a common cooling fin projecting through a slot in the construction simplifies the mechanical problems involved andprovides ample grid cooling. Two of these tubes are shown in Fig.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
