. The Bell System technical journal . move by an increment Ay. The relation ; and Ay is given by the following equation: 1 , 27rAv cot <p Bo (1) where Xy and Xx are the respective wavelengths in the two lines (which maynot be equal if, for example, one is a coaxial and the other is a waveguide).BoZqiiA typical cot-cot plot is shown in Fig. 5, (2)(3) ADMITTANCES OF IARALLEL-PLANE ELECTRON TUBES 623 Now, assume that the right-liand transmission line is removed and thatthe diode gap is connected at the transformer terminals Xo. The normalizedadmittance referred to the point yo
. The Bell System technical journal . move by an increment Ay. The relation ; and Ay is given by the following equation: 1 , 27rAv cot <p Bo (1) where Xy and Xx are the respective wavelengths in the two lines (which maynot be equal if, for example, one is a coaxial and the other is a waveguide).BoZqiiA typical cot-cot plot is shown in Fig. 5, (2)(3) ADMITTANCES OF IARALLEL-PLANE ELECTRON TUBES 623 Now, assume that the right-liand transmission line is removed and thatthe diode gap is connected at the transformer terminals Xo. The normalizedadmittance referred to the point yo on the input line can be measured by asimple standing wave measurement. Represent this admittance by F^y .. Fig. 4—Coaxial tester. Let the unknown diode admittance be represented by F^ . Yx is then givenby the following relation: ^ [Yu-o + jp\ (-i) Fx = Z OxW Hence, having determined yo, it is only necessary to measure the slope mand the intercept p on the cot-cot curve in order to relate Y:, to Y,,.g . Thecharacteristic impedance of the output line Zqx used in obtaining the cot-cotplot must also be known. Since a coaxial is used for this line, its charac-teristic impedance is easily calculated. If no losses were associated with the transformer or the parts of the diodeexternal to the actual cathode-anode region, such as the metal vacuum 624 BELL SYSTEM TECH MCA L JOURNAL envelope and certain ceramic details of the tube, the above measurementswould give complete information regarding the circuit. Certain losses havebeen found, however. These are measured as follows: At the time whenterminals .vo are shorted a standing wave measurement is made in the wave-
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
