Downloaded from https://www.everyspec.com MIL-STD-1311D 2.1 Idling anode current. For production purposes, the manufacturer may use a fixed value of Ibo provided the value chosen is representative of the current product. For a change in power output with reduced filament or heater voltage, the reading at the reduced voltage shall be taken when the value of the power output is rising or stable. T1 - 5-A variac. T2 - Low-impedance transformer. R1 - 10,000-ohm noninductive 8-watt rheostat. R2 - 500-ohm ± 5 percent noninductive 4-watt resistor. V - ac voltmeter. S1 - Microswitch normally open. FIGURE 1341-2. Circuit for measuring class B power output. METHOD 1341 1341-2 19 April 1968