Sept. 24, 1946., H. G. BUSIGNIES ’ ‘ ‘ 2,408,041 INSTANTANEOUS VISUAL DIRECT-ION FINDER Filed May 22, 1941. ELEC TRON GUN ‘10 I INVENTOR BY. . HEX/é 61'?V6/6W/55' ATTORNEY Patented Sept. 24, 1946 2,408,041 ‘ UNi'i'ED STATES PATENT OFFICE 2,408,041 IN S TAN TAN EOUS VISUAL DIRECTION FINDER Henri G. Busignies, Forest Hills, N. Y., assignor to Federal Telephone & Radio Corporation, a cor poration of Delaware 1 Application May 22, 1941, Serial No. 394,645 2 Claims. (Cl. 250—11) This invention relates to direct reading direc tion finders, and more particularly to direction ?nders using cathode ray indicators. In the past cathode ray direction ?nders have been proposed in which a cathode ray beam is rotated at a rate determined by the rotational frequency of a directive receiving antenna and a radial de?ection of the rotating beam is pro duced by application of directive signals to an accelerating electrode of the tube, by applica 2 arranged concentrically of electrode H and pref erably is of a substantially pointed or conical form. A two-phase generator At may be pro vided, this generator being operated by a motor M simultaneously with rotation of search coil Sc. The output of generator At is applied over ?lters Fa, Pb and switching device Ib to the four con ventional electrodes Pa to Pd, so as to produce a uniform rotation of the cathode ray beam gen ill erated by electron gun Ill. The speed of rota tion of directive signals to the conventional de ?ecting electrode system, or by a mechanical commutator arrangement. While such direction ?nder systems are satis factory it is preferable to provide some other 15 positive means for causing radial de?ection of the beam. According to my invention a direction indi tion of the beam is caused to be the same as the effective rotation speed of the antenna through the operation of search coil Sc. Ac cordingly, the beam will trace a circle on the screen of the cathode ray tube corresponding to the angular directional effect of the antenna sys tem. The recti?ed signals from the output of re cator is provided in which a pair of substantially ceiver Re are caused to ?ow through a resistance frusto-conical electrodes are used to produce the 20 R to produce a potential difference. This poten radial de?ection. Thus the de?ection of the tial is then applied between electrodes II and I2 cathode ray may be accomplished independently to cause radial de?ection of the rotating beam of the accelerating supply potentials, the rotary corresponding to signal energy received. Thus, de?ection effects and without additional me as the search coil is rotated indentations or ex chanical means. 25 tensions in the circular pattern are produced in A better understanding of my invention and dicative of the angular rotation of sources of the objects and features thereof will be had from received energy. a particular description thereof made with ref It should be understood that the sense of de erence to the accompanying drawing, the single ?ection produced by electrodes l I, I2, will depend ?gure of which illustrates a circuit embodying 30 upon the polarity of the potential applied be the features of my invention. tween these electrodes. Furthermore, because of The wave collector is shown as a pair of loops the uniform annular arrangement of these elec C1, C2 representing a crossed loop system. It is trodes the radial de?ection Will be the same in clear that if desired other forms of directive an any angular position of the beam depending only tennae may be used, such as for example, an 35 upon the strength of signal potential developed Adcock aerial. A generally non-directional an across the resistance R. If the potential is suf tenna A3 is provided to give sensing indication. ?ciently great the pattern traced on the screen Crossed loops C1, C2 are connected to stator may be in the form of a double pointed ?gure, windings B1, B11, B2, B22, respectively, to provide reducing nearly to the center of the screen for the well known goniometer arrangement having 40 the strongest or weakest point of the signal. Such a search coil Sc. The search coil So is coupled a pattern, as produced by an alternate method to coupling circuit S and over this coupling cir has been disclosed for example in my copending cuit to receiver R0. Receiver Re serves to rectify application Ser. No. 380,759, ?led February 27, the signal so that at the output thereof impulses 1941. corresponding to the rotation of search coil So 45 It should be understood that rotation of the‘ are produced. Sensing antenna A3 is connected cathode ray may be made by means of electro over switching device Ia to coupling coil S magnetic de?ecting elements or by a pair of de so that its effect can be obtained whenever sens ?ecting elements rotated at the proper speed ing indications are required. A tube forming an oscillograph indicator is provided, this tube P 50 around the cathode ray tube. The particular form of system used for developing the normal having an electron gun I!) for conventional de rotation of the beam is not a feature of this in ?ector plates Pa, Pb, P0 and Pd, and a special vention. pair of de?ector electrodes H, I 2. Electrode H When a sensing indication is desired, switch Ia is made hollow and annular in form, and shaped as a frusto-conical element, While electrode [2 is 55 is operated downward to couple antenna A3 to coil S and switch ID is operated to connect the 2,408,041 > wire normally connected to plate Pa to plate Pb, the wire normally connected to plate Pb to plate Po, the wire normally connected to plate P0 to plate Pd, and the wire normally connected to plate Pd to plate Pa. This change in connection to the normal de?ecting plate is made in order to secure a 90° rotation of the sensing pattern on the screen so that it will properly align with 4 for producing a cathode ray beam, de?ecting means for producing a rotation of said electron beam, and a pair of radial de?ection electrodes arranged in the path of said beam, one of said electrodes being of hollow frusto-conical shape and the other electrode being of substantially conical shape so that the said cathode ray beam while rotating passes through the annular space between said electrodes receiver means includ the normal direction ?nding pattern, A power ing effectively rotating directional antenna means supply circuit P20 is illustrated to supply all the’ 10' and means for detecting signals received by said the oscillograph gun and ’ power for the receiver, antenna means, and means for applying a poten the driving motor. The above given description applies to a par- 7 ticular embodiment of my invention but should tial proportional to said detected signals between said radial de?ection electrodes, whereby said beam may be de?ected over the screen of said not be considered as a limitation thereon. It is 15 cathode .ray tube to produce a relatively sharp clear that if desired a rotatable loop could be visual direction indication thereon. used in place of the ?xed antenna and goniom 2. A direction indicator according to claim 1, eter arrangement. Many other variations of my wherein said beam is rotated in timed relation invention may be made without departing from 20 with effective rotation of said directive antenna the scope thereof. What is claimed is: . ' _ '1. A direction indicating arrangement includ ing cathode ray tube, comprising an electron gun means. HENRI G. BUSIGNIES.