1P40/930 Red In-Fared Sensitive Gas Phototube. 1 X 6SL7GT JAN / CG USA MADE MAY 1953. 2 X 5Y3GT GE JAN / CG USA MADE MAY 1953. 1 X 930 PHOTO TUBE Continental Electric Co. Date 231 -. - Early versions have an RF shield sprayed on inside the glass (grey glass), and then since about 1952 were made of clear glass.
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