GB606019A - Improvements in or relating to radio detecting and ranging devices - Google Patents

Abstract

606,019. Radiolocation ; valve circuits. PHILCO PRODUCTS, Inc. Jan. 8, 1946, No. 679. Convention date, Jan. 27, 1945. [Classes 40 (vi) and 40 (vii)] In a radar system comprising transmitter 1 and receiver 2, the first-received echo of each pulse serves to trigger the pulsing of the transmitter after a suitable delay, the system thus being unresponsive to additional echoes of each pulse from more remote objects. The flip-flop circuit comprising valves 15, 16 is arranged with valve 15 normally conducting. An incoming signal fed to the second detector 9 of the receiver, lowers the cathode potential of valve 16 which is thus cut-off sharply clue to the coupling through capacitor 21 for a time interval (say 1000 microseconds), set by the time constant of capacitor 21 and resistor 22. At the end of this interval the circuit restores and the positive pulse at 19 is fed through the capacitor 20 to cause the transmitter to emit a pulse. The cyclic operation of the system may be initiated by random disturbance, or by a vibrating contact 24 applying periodically a positive pulse to the transmitter or by similar stimulation of the receiver. When the transmitter is operating cyclically, the average D.C. voltage across the cathode resistor 25 and smoothing capacitor 26, as indicated by meter 27, is a measure of the range of the reflecting object.