Abstract: A circuit is illustrated for eliminating a repetitiously occurring or constant frequency pulse signal from a train of signal pulses. The design is such that a plurality of such circuits can be connected in series to eliminate several of various frequency repetitious pulse signals, leaving only asynchronous signals in the pulse stream presented to downstream circuitry. The concept used is to record the time between two pulses and delete the passage of any signal during a time subsequent to the second of the two pulses by an amount equal to the difference between the first two pulses. If a pulse is detected during that time window, the circuit continues to blank out the passage of pulses for as long as a pulse is detected during the time window.