US2092069A - Ultra-short wave radio system - Google Patents

Description

Sept. 7, 1937.

H. E. HOLLMANN 2,092,069 ULTRA SHORT WAVE RADIO SYSTEM Filed Aug. 7, 1936 INS ULAT/ON INVIENTOR HANS ERICH HOLLMANN' Patented Sept. 7, 1937 UNITED STATES PATENT OFFICE Application August 7, In Germany avoiding interlong-wave oscillations.

It is appreciated by those skilled in the art that the circuit arrangements which have proved the most satisfactory for use in ultra-short wave of the triode discharge tube still holds first place either as an ultra-high frequency oscillation generator, or as a detector.

The object of my invention is primarily to pro- 15 vide an ultra-high frequency circuit having means, for facilitating the adjustment of the feed-back. Other objects and advantages will become apparent as the invention is further elucidated.

In describing my invention reference will be made to the accompanying drawing in which,

Figure 1 shows diagrammatically the type of circuit to which .my invention relates,

,Figure 2 shows more in detail the construc- 25 tional details of one embodiment of my invention,

Figure 3 shows a cross section along the line 3-3 of Fig. 2, and

Figure 4 shows a modification as applied to a push-pull circuit.

Referring to Fig. 1, an electron discharge tube R is provided with the usual cathode 5, anode control electrode and the cathode,

The anode-to-cathode circuit preferably includes a variable tap A on the inductive loop L, a utilization device In a receiver, the utilization device may be p either a telephone head-set or a transformer feeding to an intermediate frequency amplifier. In an oscillation generator any suitable load may be coupled to the output circuit.

By shifting the position of the tap A, the highfrequency potential components for grid and plate are varied, and the feed-back factor is varied as well. Thus the critical point between a non-oscillating and an oscillating condition adjustments of the circuit can be made accordingly. The vari- 1936, Serial No. 94,724 June 8, 1935 able tap A is conveniently pivoted at the center of the ring-shaped loop L so as to contact therewith throughout a. wide arc.

The circuit thus far described is not ideal for ultra high frequency operation since an undesirable inductive reaction takes place between the oscillatory loop and adjacent portions of the anode supply lead, including the movable tap A and the conductive arm on which the tap is mounted. Accordingly, I have found it possible to considerably improve by mounting the discharge tube and the oscillatory loop L within an opening or recess out out from a metallic plate, which may be steel, if desired.

Referring to Fig. 2, the discharge tube A is therein shown within and to one, side of an opening l1 in the thick metal plate E. The inductive loop L is mounted concentric with the opening I l. The contact arm A is supported in any suitable manner (not shown) and has its pivot center concentric with the loop L. A contact plate i9 is mounted in" a recess in the plate E and is insulated therefrom by an insulator 2i. This insulator extends beneath the contact plate l9 and is sufficiently thin .to form a suitable dielectric, whereby the contact plate l9 and the portion of the plate E may act asa coupling condenser for grounding the radio frequency currents in the loop L where contact is made therewith by the contact arm A. This contact arm is preferably resilient and engages conductively with the contact plate l9.

By virtue of the constructional features just described it is found possibleto maintain an ultrahigh frequency potential node on the loop L at or near position of contact with the contact arm A. Furthermore, the feed-back of energy may readily be controlled by moving the arm A to one side or the other of this nodal point. The coupling arrangement between the plate E may also be seen to afford a very short path for ultra high frequencies, this being of very great advantage in making suitable adjustments for operating the system on any desired carrier wave in the ultra-short wave spectrum. The output circuit shown in Fig. 1 will be understood to include the contact plate I 9 of Figs. 2 and 3. The insulator 2| protects the direct current source l3 from being short-circuited-since the positive terminal thereof leads through the utilization device H to the contact plate l9 while the negative terminal of the source l3 leads to the cathode which is also grounded at one point through the metal plate E.

The cross sectional view of Fig. 3 when considered with the plan view of Fig. 2 shows further constructional features. tact arm A may be mounted upon a spindle 23 pivoted in any suitable manner (not shown) and the circuit arrangements loop L and the grouncl ng For example, the conprovided with a grid bias resistor W may be connected between the plate E and that portion of the loop L which interconnects the grid 9 and one terminal of the capacitor C.

Referring to Fig. 4, I show a modification of the invention in which two discharge tubes R1 and R2 are provided for push-pull operation. In this case the tubes are inserted in an opening in the plate E1 in such manner as to accommodate also twoinductiive loops La and Lg.. The loop La extends between the two anodes while the loop Lg extends between the two grids respectively of the tubes R1 and R2.

In this embodiment provision is made for grounding the loop L9. at radio frequency potentials through the contact arm A and the contact plate IS, the same as in Fig. 2. Furthermore, the grid biasing lead through the loop Lg may be connected to the cathodes by means of a contact arm A1 having the grid bias resistor W1 mounted thereon for introducing a suitable impedance between the loop Lg and the plate E1 to which the cathodes are connected at one point.-

' It will be seen from observation of Fig. 3 that two oscillating circuits La CB and Lg Cg are provided where the capacitor C9. is parallel connected across the loop La between the two anodes and where the capacitor C1; is parallel connected across the loop Lg between the two grids. Also in this case provision is made for shifting the grounding points at will according to the adjustment of the contact arms A and A1.

In the embodiment shown in Fig. 4 as well as that of Fig. 2 the plate supply lead is connected to the contact plate l9 and thus not only the continuous excitation of oscillations can be adjusted at will, but also symmetry of the circuit arrangement can be exactly balanced.

A still further modification of my invention may be made in the one case in reference to the apparatus shown in Fig. 2 and in the other case in respect to the apparatus shown-in Fig. 4 ii the contact plate l9 and insulator 2| are eliminated and the contact arm A is permitted to establish connection between the loop L- (or La) and the metal plate E (RE1) In this case however, the cathode could not be grounded but the entire plate E would be charged at the high plate potential. The necessity for suitably insulating the cathode leads from the plate E introduces practical diiiiculties which cause t 'e arrangements first described to be preferred.

In the embodiment shown it is assumed that the inductive loops are situated in the plane of the metallic plateE or E1. The inductive loops may, however, be disposed in front of or in the rear of the metallic plate ifso desired but should be maintained essentially in ajplane parallel to the plane of the grounding plate E.

I claim:'

1. In a radio circuit of the class described, an electron discharge tube having a cathode, an anode and a control grid, an inductive loop and a capacitor constituting a resonant means for intercoupling the anode and control grid, a biasing resistor connected between the cathode and control grid,a source of direct current potential and a utilization device connected between the cathode and anode, a metallic member having an opening therein sufliciently large to accommodate said discharge tube and said inductive loop, a contact plate insuiatingly mounted on said metallic discharge tube arrangement the cathode,

manual control knob 25. The

member adjacent said opening, a contact arm pivotally mounted at the center of said inductive loop and adapted to slidably contact bothwith said loop and with said contact plate, said contact arm and said contact plate being in circuit between said anode and said source of direct current potential.

2. Apparatus according to claim 1 and having means including a dielectric element between said metallic member and said contact plate for electrostatically coupling said contact arm to said metallic member at ultra high frequencies.

3. In an ultra short wave system, an electron having a grid-tocathode input circuit including a bias resistor; a cathode-to-anode circuit including a source of anode potential and a utilization device; shieldin means comprising a thick flat metallic plate having an opening therein arrangement, said opening being of circular outline for at least a portion thereof; a capacitor; an inductive loop serially connected from the anode of said discharge tube arrangement through said capacitor charge tube arrangement and forming a resonant circuit, said loop being concentric with the opening in said shielding means; and feed-back adjusting means in circuit between saidutilization device and said loop, the last said means constituting a contact plate and an adjustable contact for accommodating said to the grid of said disarm pivoted at the geometric center of said loop metallic plate surrounding and shielding said arrangement, a contact segment insulatinglymounted in electrostatic association with a recessed portion of said plate, an inductive loop connected to the anode portion of said electron discharge arrangement, and means including a rotatable contact arm for adjustably bridging the inductive loop and the contact segment.

5. A push-pull electron discharge tube arrangement according to claim 4 and having two electron discharge tubes of the triode type, the anodes of said'tubes being interconnected by said inductive loop, a second inductive loop disposed within the orifice of said plate and interconnecting the control grids 0! said tubes, and means including a second rotatable contact arm having a grid leak resistor interconnec ing inner' and outer contact elements, for providing an adjustable leakage path between the control grids and said metallic plate.

6. In an ultra-high frequency regenerative circuit arrangement, a triodeelectrondischarge tube having an anode, a cathode and a controlgrid, an inductive loop and a capacitor interconnecting said anode and control grid, a grounded conductive medium shielding andsurroundingthe zone in which said loop lies, a source 01 potential for rendering said anode positive with respect to said source being connected at a suitable point along the arc of said loop, a rotatable contactor arm through which said potential is applied to said loop, and an arcuately formed plate disposed in a recessed portion of said surrounding conductive medium and in electrostatic association therewith, said plate being in contact with a portion or said rotatable arm.

HANS ERICK ROMA CERTIFICATE OF CORRECTION. Patent No. 2,092,069. September 7, 19 7.

I HANS ERICH HOLLHANN.

It is hereby oertifi'ed that the above numbered patent was erroneously issued to the inventor, said "HCBLLMANN" whereas said patent should have been issued to Telefunken Gesellschaft fflr' Drahtlose Telegraphie m. b H. Berlin, Germany, a corporation of Germany, v as shown by the record of assignments .in this off-lee; and that the said Letters Patent should be read with this correction therein that the same may conform to the rec- 6rd of the case in the Patent Office.

Signed andesealed this 10th day of January, A. D. 1939.

a I Henry Va n Ars dale (Seal) f Acting Commissioner of Patents.

v CERTIFICATE 0 commcnon. 7 Patent No; 2,092,069. September 7, 1937.

mus ERICH HOLLHANN.

It is hereby cer'tifiediflaat the above numbered patent was erroneously issued to the inventor, said "HoLLMANN" :whereas' said patent should have been issued to Telefunken Gesell schaft fflr Drahtlose Telegraphi'e' m. b.

H., Berlin, Germany, acorporation of Germany) as shown by the record of assignments .in this off-ice; and that the said Letters Patent should be read with this correction therein that the same may conform to the rec- 6rd of the case in the Patent Office.

Signed andtsealed this 10th day of January, A. D. 1959.

. Henry Van Ars dale -($ee.l) f Acting Commissioner of Patents.

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