US1569353A - Wireless receiving system - Google Patents

Description

Jan. 12 1926.

Q. A. BRACKETT wnumss RECEIVING SYSTEM INVENTOR 'Qumcyl. Bracket! Filed August 5 1919 WITNESSES:

ATTORNEY Patented Jan. 12, 1926.

UNITED STATES PATENT OFFICE.

QUINCY A. BRACKETT, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

WIRELESS RECEIVING SYSTEM.

Application filed August 5,3919. Serial No. 315,893.

To all whom it may concern:

Be it known that I, QUINCY A. BRACK- n'rr, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Wireless Receiving Systems, of which the following is a specification.

My invention relates to wireless receiving apparatus and it has for its object to prom e apparatus of the character designated that shall be simple and rugged in construction and highly effective in operation to produce clear and distinct signals in the local circuit, even although the incoming impulses may be relatively weak in character.

In the accompanying drawing, Fig. 1 is a diagrammatic view of a Wireless receiving circuit embodying one form .of my invention; and Figs. 2 and 3 are similar views of modifications of the circuit shown in Fig. 1.

In the recei t of wireless signals, the energy derived rom the antenna is generally insuflicient in amount to produce clear and audible signals if used directly. It is usual, therefore, to employ an amplifying device, this frequently taking the form of an evac: uated tube provided with an electron source, such as a hot cathode and with a cold anode, these two electrodes being placed in the local receiving circuit and separated by a grid electrode connected to the antenna. The number of electrons flowing between the hot cathode and the cold anode and, consequently, the current flowing in the local circuit, is determined by the grid potential, and thus a current impulse derived from the antenna circuit may be amplified or multiplied many-fold for application to the local receiving circuit.

In accordance with the present invention, I attain the same general result as above outlined but I cause the antenna circuit to control an electron stream which intercepts o1 interacts with the electron stream related to the local receiving circuit. Variations in the number of electrons flowing in the antenna electron stream vary the number of colfects or other interactions with a consequent disturbing effect upon the electron stream relating to the local receiving circuit. Thus, current variations may be multiplied manyfold in order to secure clear, shar and distinct signals, with relatively wea antenna .energiz ation.

Referring to the drawing for a more detailed understanding of my invention, I show a receiving antenna at 5 in Fig. 1, the antenna being connected to ground through the primary winding 6 of a coupling transformer 7 having a secondary winding 8. The secondary winding 8 is connected to the anodes 9+9 of an evacuated receiving bulb 10 that is further provided with a hot cathode 11, preferably disposed diametrically opposite the anodes 99. The cathode 11 is energized, as by a suitable battery 12, and is connected to substantially the mid-point ofthe secondary winding 8.

The elements thus described serve to rectify any alternating electromotive force generated in the winding 8 and to produce a unidirectional electron flow from the cathode 11 to the anodes 9-9, all as set forth and claimed in detail in my eopendingapplication, Serial No. 442,381, filed Feb. 4, 1921.

The tube 10 is further provided with a hot cathode 13 disposed opposite a plate anode 14, these two electrodes being included in a local receiving circuit embodying a receiver 15 and a current source 16, shown, in this case, as a battery. The electrodes 13 and 14 are so disposed that an electron stream therebetween is intercepted by the electron stream between the electrodes 99 and the cathode 11.

Having thus described the arrangement of apparatus embodying my invention, the operation thereof will be as follows: Upon closing the receiving circuit and heating the cathode 13, as by a battery 17, an electron stream flows from the cathode 13 to the anode 14, producing current flow in the opposite direction through the local receiving circuit. Upon the receipt of signals on the antenna 5, alternating current is produced in the secondary winding 8 and is rectified by the anodes 9-9 and the cathode 11, producing electron flow from the cathode 11 to the anodes 99, this electron stream intercepting or otherwise interacting with that existing between the electrodes 13 and 14. The collisions of the electrons, or interactions resulting from static-field or other effects of the electrons, in what may be called the antenna electron stream, with the electrons in the local-circuit electron stream causes the latter to be diverted from its true path so that the electrons thereof do not impact upon the anode 14, producing current variations in the local receiving circuit. By proper design, these current variations may be caused to greatly exceed the current variations in the antenna circuit itself, thus producing loud and clearly distinct signals in the receiving device 15.

Referring to the form of my invention shown in Fig. 2, an antenna 5 receives the signals, as before, but may be closely coupled to the local receiving circuit, as through an auto-transformer 20. The receiver bulb embodies the same number of electrodes as before but they are differently arranged, as follows: The hot cathode 11 ertaining to the antemia circuit is disposed opposite the antenna anodes 9-9 but is spaced sufliciently away from the opposite wall to permit the positioning of the plate anode 14 therebehind. The hot cathode 13, pertaining to the local receiving circuit, is disposed between the hot cathode 11 and the anodes 9-9. Thus, in operation, the electron stream pertaining to the antenna circuit may be indicated by an arrow 21, and the electron stream pertaining to the local circuit by an arrow 22, pointing in the opposite direction. The local receiving circuit is shown as being energized as in the system of Fig. .1.

Having thus described the arrangement of the system of Fig. 2, the. operation is as follows: Upon establishing {connection to the source 16, an electron stream flows from the cathode 13 to the anode 14, as indicated by the arrow 22. The resultant current flow is uniform and so produces no noise in the receiver 15, after the initial click. The receipt of signals produces spaced electron discharge or spurts from the cathode 11 to the anodes 9 and 9 as indicated by the arrow 1,. in the .opposite direction from that indicated by the arrow 22. Thus the receipt of a signal causes serious interference or other reaction with the electron flow in the local circuit, with the reproduction of clear, audible signals.

In the form of my invention shown in Fig. 3, the general arrangement of circuits is the same as that shown in Fi 2 but a somewhat different type of amp ifier' tube is employed, in that the flow of electrons in the antenna electron path is such as to assist the flow of electrons in the local receiving path, thus increasing the current flow and the loudness of signals in the receiver upon the receipt of incoming signals, rather than by decreasing the electron stream, as in the system of Flg. .2. Thus, the anodes 9-9 are disposed opposite the antenna cathode 11 and the local circuit cathode 13 is disposed in proximity to the antenna cathode 11. The local-circuit plate anode 14 is disposed between the rectifying anodes 99. The antenna electron stream may be indicated in position and direction by an arrow 30, and the electron stream pertaining to the electron receiving circuit by a similar arrow 31, substantially coincident with the arrow 30.

Upon closing the local receiving circuit,

- the electron stream 31 is initiated between the electrodes 13 and 14 and flows with fixed characteristics until signals are received on the antenna 5. Under these conditions, electron flow from the cathode 11 to the anodes 99 is indicated by the arrow 30 and the effect of this electron stream is to materially increase the number of electrons driven over from the cathode 13 to the anode 14. Thus, an incoming im pulse on the antenna results in marked increase of the current in the local receiving circuit, thus producing a clear signal as desired for good transmission.

Still other changes will be obvious to those skilled in the art, such, for example, as the use of various types ofcoupling and the use of two or more amplifier tubes to still further increase the intensity of the signals.

While I have shown and described my invention in its preferred forms, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various chan es and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or are specifically set forth in the appended claim.

I claim as my invention:

In a wireless receiving circuit, the combination with an antenna havin a coupled transformer associated therewlth, of an evacuated bulb provided with anodes and an electron emitting cathode, said anodes being connected, respectively, to terminal points of the secondary winding of said transformer, and said cathode being connected to an intermediate point therein, whereby said electrodes tend to rectify an electromotive force produced in said winding and, consequently, to produce unidirectional electron flow from said cathode to said anodes, an additional electronemitting electrode and a cold anode also mounted within said container and so disosed that an electronpath therebetween mtercepts the aforementioned electron stream, and an electrical receiving circuit connecting said last-named electrodes and embodying a source of electromotive forces and a receivingdevice, whereby an electromotive force supplied through said coupled 7 5 transformer to said anodes produces interlocal receiving circuit because of modifications of the number of electrons traversing the same.

In testimony whereof, I have hereunto subscribed my name this 30th day of July,

QUINCY A. BRACKETT.

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