AbstractsEngineering

Measurements of input admittance of triodes in the frequency range 300 Mc/s to 900 Mc/s.

by Zdzislaw. Poznanski




Institution: McGill University
Department: Department of Electrical Engineering.
Degree: Master of Engineering.
Year: 1950
Keywords: Electrical Engineering.
Record ID: 1556427
Full text PDF: http://digitool.library.mcgill.ca/thesisfile124302.pdf


Abstract

Measurements of input admittance, over the frequency range 300Mcs/s. to 900Mcs/s., were made on four different types of triodes represented by the HY75, 826, 388, 957. A coaxial resonant line was used as the measuring device. It was found that the cold tube input admittance increases rapidly with increasing frequency over the normally used range, passing through alternant poles and zeros. This indicates that another usefull range of tube operation may be obtained at frequencies higher than the first series resonant frequency. Also the inductive input susceptance observed in that range may be found usefull. An indication of transit time effects was also obtained though it would appear that in most high frequency triodes the top frequency limit is mainly determined by the cold tube circuit effects.