Downloaded from https://www.everyspec.com MIL-STD-1311D q. Peak forward grid voltage (egy). The unloaded pulse amplitude presented to the grid of the TUT. This amplitude is the algebraic sum of the total drive and the bias voltage, if any. The grid pulse characteristics shall be defined as shown on figure 3 . FIGURE 3. Grid pulse. r. Peak inverse grid voltage (egx). The peak inverse grid voltage is the maximum voltage applied to the grid with respect to the cathode in the inverse direction. s. Unloaded grid bias voltage. The dc voltage at the grid terminal with respect to the cathode socket terminal, with the tube removed. t. On load grid bias voltage.
The inter-pulse negative dc voltage at the grid with respect to the cathode, when the tube is operating. u. Forward grid impedance. The output impedance of the grid drive and bias circuit. (See trigger source impedance.) v. Recovery impedance. The impedance of the circuit network composed of the primary quantities, resistance, inductance, and capacitance. w. Grid firing time. The time interval between the instant of simultaneous application of heater, reservoir, and specified grid voltages; and the instant when the grid-cathode gap ignites. x. Recovery time. The time required after interruption of forward anode current for the grid to regain control, under specified operating conditions. y.
Anode heating factor or anode breakdown factor (Pb). The product of peak forward anode voltage, peak anode current, and pulse repetition frequency. P b = epy X i b X prr. This is an indication of the energy dissipated in the tube during breakdowns. 4.12.2 Instructions for test conditions. 4.12.2.1 Grid pulse characteristics. The grid pulse characteristics are properties of the output pulse of the trigger circuit, measured at the grid input of the tube with the grid disconnected.
The oscilloscope input shall be fed either directly or from a capacitance divider or compensated resistance voltage divider tap, as appropriate, and this voltage connected to the vertical input preferably by a matching coaxial cable. The voltage ratio of dividers plus associated cables shall be calibrated against a direct oscilloscope measurement. The test circuit shall be arranged to compensate for the removal of measuring equipment when the tube is operated. egy: Measured with a capacitance divider and an oscilloscope.
(See figure 3 .) An electrostatic peak reading voltmeter may be used as an alternative means of measurement provided no leading edge spike appears on the unloaded grid pulse. tr, tf, tp: Measured by examining the oscilloscope presentation as shown on figure 3 . 9