RESEARCH AND DEVELOPMENT ON L-BAND CROSSED-FIELD AMPLIFIER CHAIN
Quarterly progress rept. no. 7, Jun-Sep 1964
S F D LABS UNION NJ
Pagination or Media Count:
Life tests were continued on the Group C, SFD-209 tubes. Tubes L30E, D37F, and L48E are operating in parallel from a common RF source and dc power supply. A total of 8349 hours of operation was accumulated. Apparent degradation of performance was traced to external circuit faults. With circuit faults corrected, tube L48E had no significant change in performance after 3268 hours of operation. Tubes L30E and D37F are operating satisfactorily after 748 and 769 hours, respectively. Group D tubes were constructed, and incorporate improved control electrode cooling and a new input window. Tubes F63F and G35F of the new Group D design were tested and found to be satisfactory. Tube G35F was used to observe the effects of increased anode-cathode separation which allows operation in the region of lower power output, where under conditions of less separation, the output would contain some pi mode oscillations. Starting delay in tube G35F was also studied. Starting delay times of less than 20 nanoseconds were observed for a 5 kw peak input over a 1000 volt range of cathode voltage encompassing the normal operating values.
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