US 1489287 A
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" Zit/amm? April s, 1924. i 1,489,281
A H. TAYLQR v RECEIVER 0F HIGH FREQUENCY ELECTRICAL SIGNALS Filed May` 29. 1923 4. szwpM/g 8f/.#43, 17M# FS A l gwuenot v ,K
* Albert H. Taylor Patented Apr. 8, 1924.
UNITED STATES- iaamacsf ALBERT H. TAYLOR, OF WASHINGTON, DISTRICT OF COLUMBIA.' I
RECEIVER F HIGH-FREQUENCY ELECTRICAL SIGNALS.
Application led Hay 29, 1923. Serial No. 642,354.
To all whom t 'may concern:
Be it known that I, ALBERT H. TAYLOR, a citizen of the United States, and resident of Washington, Districtof Columbia, have made new and useful Improvements in Receivers of High-Frequency Electrical Signals, of which the following is a specification.
My invention relates particularly to the reception of a multiplicity of h1 h frequency electrical signals employing t e same collector or antenna.
The particular object is the multiple reception of such signals without disturbing reactions between the several receivers connected to the one collector.
My improvement is of particular value on ship-board where it may be desirable to receive a large number of signals simultaneously, and where the facilities for rigging a number of antennae are limited.
My invention will be best understood by reference tn the accompanying drawing, the figure illustrating its use for the reception of radio signals. In the figure A is an antenna having a high resistance in series therewith. The thermionic vacuum tube V has its grid circuit connected between two points in this resistance. The plate circuit of this vacuum tube contains the tunable high frequency circuit having inductance L, and variable capacity C, in parallel relation. I nd it preferable to make the ratio of inductance to capacity in this circuit lar e. There is also included in this circuit a evice J which I term a rejector. It comrises a very low inductance element having very low resistance, usually being one or more turns of very heavy copper strip or wire and a large capacity condenser constructed to have small resistance, the condenser being made variable in order to permit of tuning the rejector element to the desired wave length. Shunted around the rejector is a tunable circuit containing inductance L2 and variable capacit C2 in series. A receiver is associated with t is last named circuit usually through a tunable circuit containing inductance L3 and yariable condenser C3 with leads to detecting device or to an amplifier and detector as desired. B1 is a source of current for heating the filament of vacuum tube V and B2 is a source of current for the plate circuit of this vacuum tube. These same sources may be used in connection with the amplier and detector if vacuum tubes are used in connection therewith. The capacity C4 is referably large and is introduced mainly or the purpose of preventing a short circuit of battery B2. The antenna may be tuned but this 1s nptgessential,efliighresistanceR in s'ies tlie'iewithrendersit.aperiodie.
Aiy number of receivers may be connected with the antenna through similai` vacnum tubes and circuits as described above through additional leads connected between points in the resistance R as illustrated. I term the vacuum tubeanonplingtube besalisespseurTestHeccllectcrto the Selectlve Girsilitsanireeerer as illustrated and atthsame time prevent-sa reactioncaused by va'tionds'in these circuits onotherircutsiiictdtdlthfcellector.
The operation of the system is as follows Assuming that a number of signals of different frequencies are being collected on the antenna A, the desired signal is selected out by tuning the inductance L1 and C1 to this frequency which admits this particular signal to the circuit containing these elements. However, as other signals cannot be entirely excluded from this circuit, the tuning of the rejector J to the frequency of the desired signal permits further selectivit the desired signals being accepted by the rejector and all other signals being rejected or bypassed by the low inductance element of this device. The desired signals are then passed on to the receiver throu h the tuned circuit containing inductance 2 and capacity C2, any residual undesired signal being excluded from this circuit through being out of tune with it.
To aid in picking up signals I provide the switch S which in its up position eliminates the intermediate selective circuits, connecting the couplin tube directly to the circuit containing inductance L2 and capacity C2. This arrangement not bein very selective permits of the signal being picked up promptly and adjusting the receiver containing inductance L3 and capacity Cs to the desired frequency. Havin found the desired signal and adjusted t e receiving circuits, the switch S is thrown to the down position connectin in the intermediate selective circuits an these are then tuned until the desired signal is brought in and the undesired signals excluded.
Having described my invention I claim:
1. In a system for the reception of high frequency electrical signals the combination of a collector' circuiti having 'a high resist ance in series therewith, a couphng thermionic vacuum tube having its input cir-v cuit connected between two *p'oinssimsaidA resistance and an output circuit having in series therewith a tunable circuit containing variable constants in parallel relation, a tunable rejector circuit in series relation Within said tunable' circuit, a tunable circuit-in parallel relaton'to said'rejector, and-a receiver associated with said last tunable circuit.
2. Ina system for the reception ofihigh' No references cited. i
ance in series therewith, an
frequenc electrical signals the combination 15