Undesired signal canceller

Claim 1

AN UNDESIRED SIGNAL CANCELLER COMPRISING FIRST AND SECOND CHANNELS FOR RECEIVING DESIRED AND UNDESIRED SIGNALS COMPOSED OF REFLECTIONS OF TRANSMITTED RADAR PULSES WHERE SAID TRANSMITTED RADAR PULSES HAVE FIXED PULSE REPETITION RATES, SAID DESIRED SIGNALS CONSISTING OF REFLECTED PULSES OF RELATIVELY SHORT DURATION-USUALLY ONLY AS LONG AS A TRANSMITTED PULSE, SAID UNDERSIRED SIGNALS CONSISTING OF REFLECTED PULSES OF RELATIVELY LONG DURATION-USUALLY AS LONG A STOW OR MORE TRANSMITTED PULSES, SAID FIRST CHANNEL INCLUDING TIME DELAY MEANS FOR DELAYING RECEIVED SIGNALS BY A TIME PERIOD EQUAL TO THE TIME PERIOD BETWEEN THE TRANSMITTED RADAR PULSES, SAID FIRST CHANNEL PROVIDING DELAYED SIGNALS TO A FIRST TERMINALS, SAID SECOND CHANNEL INCORPORATING A VARIABLE DELAY LINE CAPABLE OF INTRODUCING VARIOUS TIME DELAYS TO SAID DESIRED AND UNDESIRED SIGNALS IN RESPONSE TO CONTROL SIGNALS, SAID SECOND CHANNEL PROVIDINT OUTPUT SIGNALS TO A SECOND TERMINAL, MEANS INCLUDING A DISCRIMINATOR COUPLED TO SAID FIRST AND SECOND TERMINALS FOR SENSING THE RELATIONSHIPS BETWEEN SIGNALS ON SAID TERMINALS AND FOR GENERATING A CONTROL SIGNAL TO CHANGE THE DELAY TIME OF SAID VARIABLE DELAY LINE WHEN SAID RELATIONSHIPS ARE NOT SUCH AS TO CAUSE THE CANCELLATION OF UNDESIRED SIGNALS, AND MEANS COUPLED TO SAID FIRST AND SECOND TERMINALS TO RECEIVE AND CANCEL SAID UNDERSIRED SIGNALS AND TRANSMIT SAID DESIRED SIGNALS.