US1751588A - Wireless receiving set for compensating disturbances - Google Patents

Description

March 25, 1930.. s. LOEWE l 1,751,588 WIRELESS VRclarlvnm SET FOR'COMPEN'SATING DISTURBANCES Filed 'July 27, 1926 Patented Mar. 25, 1930 UNITED 4sriyrizs .PATENT OFFICE v SIEGMUND LOEWE, OF BERLIN, GERMANY, ASSIGNOR TO RADIO. CORPORATION OF AMERICA, A CORIORATION OF DELAWARE WIRELESS RECEIVING SET FOR COMPENSATING DISTURBANCES AppIication led lJuly 27, 1926, Serial No; 125,313, and in Germany August 1, 1925.

This invention relates to wireless receiving sets, and has particularly for its object to suppress'the disturbances which are especial- 1y caused by electrostatic conditions.

By careful investigations I have found that these disturbances may be fully suppressed in the following manner:

The receiving aerial is carried in series or parallel connection through two similar rem ceiving sets E1 and E2. These receiving sets may be of any desired construction, and may, for instance, consist of a three-valve reflex set. One of these sets, for instance E1, is sharply tuned to the wave to be received and enerally so adj usted, that the reception will e as good as possible. The reception will in this case comprise to a great extent atmospheric and other disturbances, which are mixed with the reception. The second receiving set is sharply tuned to a wave, which is not very diil'erent from the wave, to which the other set is adjusted. This second receiving set, being out of tune with respect to the wave to be received, will not be acted upon by the latter. The disturbances, however, will be received by said second receiving set in equal strength and phase. If the reception be designated with E and the disturbances with S, the first receiving set will reproduce in a telephone or loudspeaker the sum of the reception and the disturbances, that is E' plus S, while the second receiving set will solely reproduce the disturbance, that is S. The diiliculty now consists, to solely reproduce the difference of the t-Wo energies received b the two receiving sets that is the quantity (E plus S) HS.

In the accompanying drawing I have represented a wireless receiving set accord- 40 ing to my invention. Fig. 1 is a wiring diagram showing diagrammatically the connections of the wireless receiving set according to my present invention. Figs. 2 and 3 are wiring diagrams showing connections for modiiied wireless receiving sets according to my invention. l

According to the connections shown in Fig. 1 the operation is as follows:

Instead of the telephone or loudspeaker,

a resistance for alternating current, that is a clioke coil or a resistance having ahigh-reslstance value such as Dl and D2 is inserted into the circuit of each receiving set. Paralleling these resistances D1 and D2 there are arranged metallic Aplates F1, F2 and FB, F 2 respectively, said metallic plates representing electrical capacities. Intermediate these capacities, further capacity plates F6 and F1 respectively are provided. Between the capacity plates F6 and F7 the controlling circuit of a tube amplifier V is inserted, said amplifier being for instance arranged to operate in the known capacity-resistance connection. In Fig. 1 a double amplifier is shown diagrammatically. In order to explain the operation of this device, it is, for instance, assumed, that the lower ends of the resistances D1, and D2, and therewith also the plates F2 and F4 are grounded. The plates F1 and F 2, therefore, are under the action of potential variations against ground, and more particularly the potential variations of the plate F1 will take place according to the sum E plus S, while the plate F3 will solely be under the'action of potential variations according to the quantity S. The plates F., and F7 now may be adjusted relativelyto the plates F1, F2, F3 and F2 in such a manner, that a complete compensation of the disturbances will take place. Between the plates F6 and F7 a very high resistance may be inserted in order to avoid constant charges .of the grid.

The combination may also be carried out in the manner of providing `a bridge connection for the tubes, such as is shown in Fig. 2. In this case two tubes R1 and R2 having common or separate heating and anode batteries are connected to a transformer with three windings a, b and c, the coupling between said windings being made'adjustable. The grid of tube R1 is connected to the plate F6 and the grid of tube R2 to the plate F2, said plates F6 and F7 being adjustably arranged within corresponding capacity plates, as in Fig. 1. The indicator is connected to the winding b, the cathodes of the tubes R1 and R2 are grounded and connected to the plates F8 and F7 by means of high leak resistances K. Instead of the indicator, also a multiple valve amplifier may be inserted into the Winding circuit against the disturbances received by b. It is obvious, that in the manner desaid second circuit. scribed, the grids of thez tubes R1 and R2 will In testimony whereof I have ailixed my be acted upon by the receiving set E1, accordsignature.

ing to the value e plus s; and by the receiv- SIEGMUND LOEWE.

ing set E2 according to the value of S, and 70 more particularly to an extent, which may be independently regulated by adjusting the plates F1, F2, F3 and F4. One will therefore lo be enabled to cause only the difference of 75 these two values to act upon the winding b, this being eifected by the direction in which the windings a and b are wound. In some cases also the insertion of a coupling transformer having three windings a, b and c, as 80 indicated in Fig. 3, will give the same result; in this case the Winding ais directly connected to the receiving set E1 and the winding c directly to the receiving set E2 and more par'- 3 ticularly in such a sense, that the winding b 85 `will be acted upon solely by the di'erenc'e of the actions of the two receiving sets.

I claim: 1. A wireless receiving system for eliminating disturbances comprising .two receiving 90 circuits one of said receiving circuits being tuned to the wave to be received, the other of said receiving circuits being tuned to a wave somewhat diferent from said former wave,

whereby said first circuit will receive said 95 former wave and the disturbances and said f second circuit only thedisturbances, and connections for the audio outputs of said circuit for balancing capacitively the disturbances received by said first circuit against the dis- Y 100 turbances received by said second circuit so as to obtain a combined receiving action of said circuits without said disturbances.

2. A wireless receiving system comprising o two receivers, one of said receivers tuned to 105 receive a desired signal and incidentally receiving undesired impulses, the other of said receivers being detuned with reference to said desired 'signal but receiving said undesired impulses, an adjustable capacity in each of the 110 audio frequency output circuits of said receivers, an electron emission tube amplifier including a rid and filament, a connection from the gri of said amplier to one of said capacities and a connection from the filament 115 of said amplifier to the other of said capacities whereb solely desired signal impulses ffects the t ermionic stream of said ampli- 3. A wireless receivinI system for elin1i- 120 natin undesirable distur ances comprising a plura ity of receiving circuits, one of said circuits being tuned to a desired signal frequency, another of said circuits being detuned relative to said desired frequency whereby said 125 rst circuit will receive said signal and the disturbances and said second circuit only the disturbances, and grounded means connected to each circuit audio output to balance capaci- 4 55 tively the disturbances received by said irst 130

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