US1892220A - Thermionic tube for directional reception - Google Patents

Description

Dec. 27, 1932. w, RUNGE THERMIONIC TUBE FOR DIRECTIONAL RECEPTION Filed oct. 27, 1927 INVENTOR WILHELM RUNGE BY (5),

AT ORNEY Patented Dec. 27, 193 2 WILHE'IM RUNGE, 0F BERLIN, GERMANY, ASSIGNOR T0 TELEFUNKEN GESELLSCEAFT run DRAHTLOSE TELEGRAPHIE 'm. B. 3.,

GERMANY Application filed October 27, 1927, Serial No.

The present invention relates to a convenient construction and arrangement of a thermionic tube in order to make the sameadapted to directional reception in combination with two directive antenna systems, and to insure reception as free as possible from disturbance.

In the methods heretofore used for directional reception, a directional characteristic was obtained by suitable antenna combination, which, while showing selective action for a definitedirection, exhibited only 8. limited number of zero points, with the result that, although in weakened condition, energy was received also from most other directions, so that stray waves whenever of suflicient intensity and volume would generally pass into the receiving apparatus from widely difierent directions. I

The object of the present invention is to overcome these disadvantages.

To overcome these disadvantages applicant has provided, according to the present invention, for the object of directional receiving, a thermionic tube which is so built that an action due to the deflection of the cathoderays is made dependent upon the direction of such deflection. The deflection means of such a thermionic tube are connected with two directional antenna systems. The latter, each of which may have a unilateral directional characteristic, that is, a combination of a high antenna and a loop antepgia, may be mounted in the same location, theorientation being so chosen that the directions of maximum signal strength of each antenna system enclose a definite angle in which the station to be received may lie. From the description ofthe tube and its connection with two directional antennae, the suitability and the value of the invention for directive reception will be readily understood.

Other objects and advantages will become apparent from the following detailed description when read in connection with the annexed drawing in which; Q

Fig. 1 is a diagrammatic view of a thermionic tube constructed in accordance with the present invention, and shows the tube con- OF BERLIN, GERMANY, A CORPORATION OF rnnamromc TUBE non. mancrronan nncnr'rron 229,045, and in Germany November. 5, 1926.

nected with a directional radiant energy ab sorption system,-

Fig. 2 is a view showing an end view of the deflection electrodes,

Fig. 3 shows the characteristic curves of the aerials used,

Fig. 4 shows the characteristic curve obtained, while i Fig. 5 shows a modification of the arrangement of Fig. 1.

Referring to the drawing Fig. 1 shows a thermionic tube of the kind here dealt with. Inside the tube, similarly as in a Braun tube, a cathode-ray pencil is produced between cathode C and screen X. The rays are thrown upon a screen X through two airs of deflection electrodes aa and 6?) (see igs. 1 and 2) which are disposed at right angles to each other. Potential for starting said rays and maintaining said rays is provided by sources 10 and 8 respectively. If alternating current potentials having values A and B andbeing of the same phase and frequency are connected with the pairs of electrodes ac and bb, the cathode s ot on screen X will make constantly a straig t line which forms an angle (p with reference to the direc-' tion aa. See Fig. 2. (p is a function of the relation between the voltage amplitudes. In

the case-of symmetrical construction there is said screen X hasa sector-Shap out p'ortion S in whicha similarly-shaped metal sheet drained outwardly is arranged. For a certain range of the amplitude relations B: A, as will be seen, the cathode ray pencil will strike and leave the said sector at o ceivable in a suitable receiver apparatus 6 5 connected between the source 8 and the sector S. In the presence of other amplitude relations BzA, the said metallic sector will never be struck by the cathode spot, even if the amplitudes are of any large value at all.

If, then, the tube as here described is connected with two uni-directional antenna systems which comprise closed bilateral absorption members L, L and vertical members V, V of the same directional characteristics symmetrically coupled through couplings I, 1 as shown in Figure 5, so that the potentials of the system V L L, come to act upon the pair of plates ac, and the potentlals of the second antenna system V, L, I upon the pair bb, the directional antenna structures may be so orientated that, as shown in Fig. 3, their directional characteristics 1 and 2 form an angle with each other. Obviously by suitably orientating the metallic sector in the tube it may be moved to a position at which it is struck by the cathode rays only when the amplitudes of the two potentials fed in are nearly equal. In the presence of absolutely equal amplitudes, in other words, 'at the point of intersection of the characteristics of Fig. 3, the cathode ray will be defiected by an angle of 45 degrees with reference to the direction of the field of one of. the said two pairs of electrodes. We shall assume that the line of symmetry of the collecting sector has an angle of inclination of 45 degrees with reference to the direction of the field of one ofthe pairs of electrodes so that the sector will bestruck by cathode rays under most favorable conditions when they are equal to each other coming from the main direction of reception, in other words, when they are equal from the direction in which, according to the characteristics of Fig. 3, the amplitude of the currents or potentials supplied to the tube from the two antenna struc tures are equal. To what extent also waves will be received which are at an angle with reference to this main direction of reception, will, for the same antenna systems, depend upon the central angle of the metallic sector.

In the illustration of Fig; 3 it is indicated that the collecting electrode will be struck by cathode rays when the direction difiers from the main direction by I: 7 degrees.

The angle from which reception is possible will vary according to the shape and orientation of the characteristic curves 1 and 2.

The resultant receiving characteristic has a shape as shown in Fig. 4. As can be seen therefrom, the effect which is caused by the employment of such a tube to indicate the oscillations, is sharply limited and the entire system is highly directiw In the case of waves which arrive from direction opposite to that of reception, the effect is very low as shown in Fig. 4. If the same shall be avoided inside certain limits of intensity, a

diaphra m or screening device may be mounte in the neighborhoodv of the system, or else the receiving sector may-beso disposed that its apex will not extend asfar as the point of rest of the cathode rays so that the sector will be struck by cathode rays only whenever the deflection exceeds a certain minimum value.

The idea underlying the present invention is capable of various modifications. In the f'orm illustrated in Fig. 1 it is assumed that the collecting electrode has a positive potential, and that it pertains to a circuit comprising an indicator instrument. However, also a screen which, .in well-known manner, is caused to luminesce due to the impinging cathode rays may be used as a collecting electrode. This luminous action may be brought by means of a lens 20 to act further upon a photo-electric cell 0 as shown in Figure 5, its illumination being indicated by a convenient indicator instrument 14. The screen S mayv then have the same size, position, and form as sector S, Fig. 1, and will be struck only by such cathode rays as are deflected inside said sector. Moreover, on a larger screen, a corresponding sector can be selected by screen-. ing off the light of the other parts so that only the luminousaction of the sector is brought to act upon the photo-electric cell. Also a screen may be used which emits secondary electrons whereby an indicator effect may be produced. It will be evident that the arrangement as hereinbefore described in connection with the use of cathode rays may be used with corresponding alterations also when other rays having certain electrical charges, such as canal rays, are employed.

Having now fullydescribed my invention and the operation thereof I claim:

1. A receiving system, comprising means for the generation of a cathode ray pencil, deflection means comprising two pairs of parallel plates disposed at right angles to each other, and an electron collector adjacent the normal path of said ray, the said electron collector comprising a wedge shaped sector the surface of which is at right'angles to the direct1on. of the ,uninfiuenced cathode ra s, all of the sector being outside the norma path of said rays. w

2. A receiving system, comprising means for the generation of a cathode ray pencil, deflectlon means, a target in the path of said ray, a luminous sector in said target and insulated therefrom. said sector being normally outside of the path of said ray, a photoelectric cell adjacent said tube and in the path of the radiations-from said luminous sector when energized, whereby the deflection of the cathode ray pencil by the deflection means causes the ray to fall upon the luminous sector which throws ofi' energy to the photoelectric cell and indicating means associated with said cell.

3. A unidirectional receiving system comprising a cathode ray tube having a ray producing electrode, opposed pairs of deflecting electrodes, and a target comprisin a circular disk, a wedge sha ed portion 0 which is electrically separate from the remaining portion, said wedge shaped portion being radially spaced from the normal path of the ray pro need by said ray producing electrode, indicating means connected with said wedge shaped portion, and means for applying en ergy from a unidirectional absorption system to a pair of said deflecting electrodes.

4. A receiving means as recited in claim 3 including means for applying energy from at least two unidirectional absorption systems to opposed pairs of said deflecting electrodes.

5. A unidirectional receiving system comprising a cathode ray tube having a ray pro-v produced by said ray producing means is caused to be deflected from its normal path a photoelectric cell located adjacent said wedge shaped portion and in the path of energy radiated therefrom, and indicating means connected with said photoelectric cell.

WILHELM RUNGE.

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