US1743052A - Receiver of high-frequency electrical signals - Google Patents

Description

Jan. 7, 1930. A. H. TAYLOR 1,743,052

" RECEIVER OF HIGH FREQUENCY ELECTRICAL SIGNALS Filed May 29, 1923 RADIO AMPLIFIER AND DETECTOR L LI GRID J J FIL.

? G |I|lLl-lrillllllllllllll gvvue'kfio'a Albert H. Taylor 61011101 new Patented Jan. 7, 1930 UNITED STATES ALBERT H. TAYLOR, or WASHINGTON, msrnicronconu vrnrgi,g ss enon, y rtns qn ASSIGNMENTS, 'ro FEDERAL TELEGRAPrI coivrran r, A coaronnrrron on GALI- FORNIA Application filed May 29,

of the universal type the selectivity obtained is not at all satisfactory and is not comparable with the selectivity obtained by the method of reception employing regeneration.

This absence of selectivity in receivers employing such amplifiers is often a serious disadvantage, and it is the principal purpose of my invention to provide a means of regaining this selectivity when such amplifiers are employed.

My invention will be best understood by reference to the figure in the accompanying drawing in which A is an antenna circuit containing variable capacity C and inducance L. The antenna is coupled to the secondary of a receiver container inductance L and variable capacity C This secondary tunable circuit is included in the grid circuit of thermionic vacuum tube V in which G is the well known grid leak-stopping condenser combination. The plate circuit of the vacuum tube contains inductance L coupled to inductance L in the grid circuit, providing the well known feed-back or tickler coil arrangement in connection with regenerative vacuum tube circuits. I have also employed in the'plate circuit a resistance R over a wide range of values with good results, but have found a value of 30,000 ohms particularly suitable for the circuit combination involved in this invention. When a resistance of the order above set forth is used I find it desirable to shunt this resistance and the plate circuit battery by a capacity C sufliciently large to by-pass the radio frequency currents in the plate circuit. B is a Source of current for heating the filament of the vacuum tube V, controllable through the rheostat R and this same source may be employed on the filaments of subsequent vacuum tubes employed in the amplifier and detector connected to the cir- RECEIVER or HIeH-raEQUENcy panorama; smite-Ls.

1923, s m No, 642,355.

cuit. B is a sour ce ofpotential for the plate circuit of the vacuum tube, and this-source may alsobe employed on the plate circuits of subsequent vacuum tubes used in the amplifier and detector connected to the circuit.

Instead 0fconnecting the additional stages of radio frequencyamplification to the plate circuitof the-vacuum tube V as is the ord i nary practice I connect directly to the secondary of the receiver; that is,-to. the tunable circuit in the grid circuitcontaining inductanoe L and capacity G This arrange-- 'ment avoids the use of a radio frequency transformer or coupling in theplate circuit of :the vacuum tube wh i'ch maiy :be' broad in range of amplification and therefore destroying the selectivity of the system, or if'the connection in the plate circuit is made to a tunable: circuit, the arrangement requires a second step of tuning control, thereby complicating the system.

I find that by employing the feature of regeneration with an output connection made directly to the tuned circuit in the grid circuit of the vacuum tube a system of a very high order of selectivity is obtained permitting the use of considerable amplification without destroying the selectivity.

Having described my invention I claim:

1. In a device for increasing the selectivity of radio frequency amplifiers the combination of, a vacuum tube having grid, filament and plate electrodes, connections between the input circuit of the radio frequency amplifier and the grid electrode of said vacuum tube, an inductance connected to the plate electrode of said vacuum tube, said inductance being coupled to the input circuit of the radio frequency amplifier, and a resistance for controlling the operation of said vacuum tube connected to said inductance.

2. An attachment for a radio receiving ap paratus having a radio frequency amplifier and detector system, comprising an electron tube having input and output circuits mutually coupled for regenerative action, means for damping said electron tube circuits, a radio frequency energy collecting system coupled to said input circuit, a connection between the input circuit of said electron tube and the grid of the first tube of said radio frequency amplifier and detector system for the selective transfer of signal energy of a particular frequency to said radio frequency "Amplifier and detector system.

3. An attachment for a radio receivin apparatus consisting of a broad frequency and radio frequency amplifier and detector, comprising an electron tube having input and outputcircuits, means interlinking said input and output circuits, a high resistance load for highly damping said output circuit, a

source of high frequency si a1 energy coupled to said input circuit, an connections extending between the input circuit of said electron tube and the input circuit of the first tube of said radio frequency amplifier for the selective transfer of signalin energy of a particular frequency from sai source to said radio frequency amplifier. V 4. In a device for increasing the selectivity of radio frequency am lifiers the combinationof, a vacuum tube aving grid, filament and plate electrodes, a radio frequency am plifier havinga tuned input circuit coupled to fan antenna circuit, connections between said tuned input circuit and the grid and fil ament electrodes of said vacuum tube,an in-' ductance connected to the plate electrode of ;aid va cuum tube and coupled tosaid tuned input-circuit, said vacuum tube functionin to'increase the frequency selectivity of said tuned circuit.

ALBERT H. TAYLOR.

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