GB1291320A - Display apparatus for position finding equipment working on the echo principle - Google Patents

Abstract

1291320 Pulse radar FRIED KRUPP GmbH 14 Dec 1970 [15 Dec 1969] 59335/70 Heading H4D . A display apparatus comprises a generator producing gate pulses of length equal to a display period, synchronously with the transmitter pulses of a rotating beam radar or sonar; a generator producing pulses wherever the beam passes a predetermined direction; and a marker generator producing a marker pulse equal to the gate pulse length upon simultaneous application of a direction pulse and a gate pulse, said marker pulse being applied to the cathode of a C.R.T. Radar echo pulses are passed to cathode 6 of C.R.T. 7 which has a rotating deflector 8 linked to the antenna drive 2 to produce a PPI display. Trigger pulses s produce pulses d of length #t from generator 15 which are fed to the trigger input of bi-stable 16 and inverted and fed to bi-stable 17. Unit 14 produces a direction pulse r. At the first positive edge of d during r, bi-stable 16 changes state producing the start of the marker pulse from gate 18 and sensitizing bi-stable 17 such that on the next positive edge of inverted d it also changes state terminating the marker pulse thus producing a single radial bearing marker. When r is removed the next d pulse resets the bi-stables. AND gate 18 also has inputs from a square wave generator 20 for producing dotted line markers and from a switch 19 for inhibiting marker production.