Pulse Shaper and Amplifier Circuit - TM-11-6665-209-400015

TM 11-6665-209-40

(5) The negative-going pulses from the detector circuit are now applied through

coupling capacitor C108 to the control grid of tube V103. These pulses drive

the grid of V103 more negative, which cuts off current flow and causes the

plate to become more positive. The rising plate potential of V103 is coupled to

the control grid of V104 by Q105 and C112, which causes V104 to conduct

heavily. Plate voltage for V104 is applied through the component parts of the

indicator circuit. As long as V104 conducts, V103 is cut-off by the rise in the

cathode potential of V104. This rise is caused by the flow of plate current

through common-cathode resistor R107. Capacitor C112 now discharges

through the selected resistance (range) path through switch section S102B to

ground. Tube V104 conducts until discharge of C112 is completed while CR107

eliminates any negative overshoot. At this point the control grid of V104 will

revert to its steady-state bias value and the tube will stop conducting.

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