Downloaded from https://www.everyspec.com MIL-STD-1311D 4.12.2.2 Anode pulse characteristic. With the exception of epy, the anode pulse characteristic shall be measured by examining the scope presentation of the voltage across a noninductive current viewing resistor or the output of a current viewing transformer. The anode pulse characteristic shall be measured as follows: epy: Measured with a calibrated oscilloscope and suitable calibrated compensated voltage divider or suitable peak reading voltmeter. ib: Measured by examining the scope presentation as shown on figure 4 . dt dik : The dt dik value is defined as the rate of rise of the current pulse.
It is the ratio of the current change between the 25 percent and 70 percent points of the leading edge to the rise time for that portion of the pulse. FIGURE 4. Anode pulse. 4.12.2.2.1 Resonant prr. The modulator shall be adjusted to run at the resonant prr by one of the methods given below and shall be measured with a suitable counter and timing device. a. With charging diode (see figure 1 ). The charging current waveform shall be examined on an oscilloscope, preferably as the voltage developed across a noninductive resistor inserted in series between the normally connected power supply return and ground.
The charging current appears as a series of equally spaced lobes for frequencies below resonance, and as a series of lobes jointed as cusps for the resonant frequency and frequencies above (see figure 5 ). The resonant prr is that frequency at which the lobes just join with a sharp cusp. FIGURE 5. Charging current waveforms with charging diode. 10