US2204422A - Radio signaling system - Google Patents

Radio signaling system Download PDF

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Publication number
US2204422A
US2204422A US678406A US67840633A US2204422A US 2204422 A US2204422 A US 2204422A US 678406 A US678406 A US 678406A US 67840633 A US67840633 A US 67840633A US 2204422 A US2204422 A US 2204422A
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United States
Prior art keywords
grid
circuit
anode
electrode
amplifier
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Expired - Lifetime
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US678406A
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English (en)
Inventor
Arthur V Loughren
Jerome C Smith
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RCA Corp
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RCA Corp
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Priority to US678406A priority Critical patent/US2204422A/en
Priority to FR773703D priority patent/FR773703A/fr
Priority to DER90922D priority patent/DE645177C/de
Priority to GB19511/34A priority patent/GB426109A/en
Application granted granted Critical
Publication of US2204422A publication Critical patent/US2204422A/en
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/02—Details
    • H03J3/06—Arrangements for obtaining constant bandwidth or gain throughout tuning range or ranges
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/163—Special arrangements for the reduction of the damping of resonant circuits of receivers

Definitions

  • regeneration may be provided in connection with certain of the tuned circuits, as shown, fore-xample, by Landon U. S..Patent 1,702,445, wherein a tuned neutralized radio frequency amplifier is provided with controlled regeneration means for increasing the selectivity and the general operating efficiency of such a system.
  • neutralization is provided in each amplifier stage, and regeneration is obtained by means of auxiliary electric discharge devices and associated circuits, for each stage. 1
  • the selectivity throughout a certain frequency range may Vary greatly.
  • the selectivity at the low frequency end of the range for example at 600 kc. is much greater than at the high frequency end of the range, forhexample at 1400.;kc.
  • an amplifier stage-wherein controlled regeneration ' may be applied toincrease the, operating efficiency thereof, and independently of the controlled regenerathe stage may be controlled,
  • the signal transmission efficiency or gain of The gain control feature above noted is desirable not only in signal amplifiers and the like, but in other electric discharge amplifier'circuits wherein controlled regeneration maybe utilized,
  • each stage thereof in connection with a radio frequency amplifier, each stage thereof is isolated by suitable and substantially complete shielding, and then an appropriate amount of regeneration is introduced into each tuned circuit to produce the desired regeneration effect. If the regenerationvaries with the signal frequency in the proper manner, selectivity may be made equally good atall points'in the range to be covered by the amplifier system. Resulting variations in the sensitivity of such a system, if any, may be compensated for by proper design ,of the interstage coupling'means.
  • an electron discharge device of the high gain type having suitable electrode elements, is employed in conjunction with a feed-back circuit, whereby the device may function to provide an effective amplifier and electrically coupled regeneration means.
  • the feed-back or regeneration circuit is provided in connection with this electrode and may then be so designed that its regeneration control upon the system may be in a direction to emphasize a desired end of the signal frequency range whereby substantially constant selectivity may be maintained.
  • Fig. l is a schematic wiring diagram illustrating a tuned high frequency amplifier stage embodying the invention.
  • Fig. 2 is a similar wiring diagram showing the application of the invention to a multi-stage tuned high frequency amplifier in a modification of the circuit of Fig. 1;
  • Fig. 3 is a schematic wiring diagram of a further modification of the circuit of Fig. l to provide a controlled oscillator.
  • FIG. 1 indicates a shielded, tuned, radio or high frequency amplifier stage connected with a source of signals such as output terminals 6 of a preceding amplifier or signal source indicated at 1, and having output terminals 8 connected with a load or utilization device, such as a succeeding amplifier stage indicated at 9.
  • a single electric discharge device or electronic tube 'IB is employed in the amplifier stage 5 and is so arranged in circuit between the terminals 6 and 8 that it may provide not only substantially uniform frequency band amplification in the signal channel in which the stage 5 is connected, but controlled regeneration for increasing the efilciency of the stage.
  • the device I is of the five electrode type having, in addition to the usual cathode or electron emitting element II, a control grid I2, a screen electrode I3, an anode I4, and a space charge grid I located between the cathode II and the control grid I2,
  • This may be a type of radio tube known as a pentode, as hereinbefore described.
  • Pentode tubes are well known and are described on page 5 of the publication The RCA Radiotron--Cunningham Radio Tube Manual, Technical Series No. RC-ll.
  • the pentod tube is provided with three electrodes between the cathode and the anode, these electrodes being nominally a control grid, a screen grid, and a suppressor grid in that order preceding from the cathode to the anode.
  • the suppressor grid is therefore the grid adjacent to the anode and, as is well known, is connected with the cathode for the suppression of secondary emission.
  • the electrode I3 is that grid which is normally utilized as a suppressor grid and in the drawing occupies the position of the usual suppressor grid.
  • the electrode I3 is utilized as a screen for the anode.
  • a pentode type of tube is therefore particularly well adapted for use in a system embodying the invention.
  • the space charge grid I5 may Ioe employed for the purpose of increasing the mutual conductance of the device. In accordance with the invention, however, an im portant additional use is made of this grid, namely as a source of energy for regeneration purposes. If, as is contemplated, the device I0 is so designed that the anode I4 is well shielded by the screen grid I3 from the remaining elements of the de vice, then no reaction from succeeding amplifier stages, such as the stage 9, can be fed back into the stage 5 to interfere with any condition of regeneration Which may be established in the stage 5.
  • control grid I2 and a suitable electrode to be employed for regeneration purposes are electrically coupled whereby energy may be supplied from the oneto the other.
  • control grid I2 is connected with a tuned input circuit I6 comprising a variable tuning capacitor I'I connected in shunt relation to a winding I8 of an input coupling transformer I9 which is connected with the terminals B as the signal source.
  • the grid or input winding I8 is inductively coupled, as indicated by the arrow, with a regeneration or feed-back winding 20, connected with the space charge grid I5 in a regenerative plate or feed-back circuit 2
  • the anode I4 is connected with an output or load circuit 22, in which is included a coupling device 23 for the utilization device or stage 9.
  • Operating current at suitable potentials for the device I0 is provided from a source indicated by a pair of supply terminals 24.
  • a potential divider means 25 is connected in shunt with said terminals and suitable connection with the various electrodes of the device for applying thereto proper operating potentials is made at various points thereon, as indicated.
  • the cathode II is connected with a tap 26 which is more positive than a tap 21 for the control grid I2 and its input or grid circuit I6 which, as indicated at 28, is operated at ground potential.
  • the tap points 29 and 30, for the space charge grid or regeneration anode I5 and the main anode I4, respectively, provide potentials which are more positive than the cathode.
  • the screen grid I3 is operated also at a positive potential which is preferably variable, being connected to the variable tap point 3
  • Suitable bypass capacitors indicated at 33 are provided between the various circuits and cathode to prevent undesired coupling through the supply source.
  • the inner or first grid I5 normally known as a space charge grid, is utilized as a regeneration plate electrode and is connected with a potential source more positive than the cathode, as above described.
  • the feed-back coupling means which in the present example is the winding 20, serves to supply energy to the input circuit I6 through its coupling with the coil I8.
  • this feed-back arrangement is substantially independent of the operation of the device as a signal amplifier and that the amplified signal output through the circuit 22 from the main output anode 14 may bevaried also, independently, by variation of the potential on the screen grid l3 by adjustment of the variable contact 3
  • the second or middle grid is utilized as the control grid, while the outer grid functions as a screen and gaincontrolling electrode or grid.
  • the first or spacecharge grid as a regeneration plate electrode, as above mentioned, is electrostatically shielded from the main output anode I4, by'the screen'grid structure.
  • the transductance of" the device I is, therefore, variable through variation of the controlling potential on the screen or outer grid l3, as above described, at the same time, the
  • transductance of the device through the space charge grid or regeneration anode I is substantially independent of the control of the transis utilized in a receiving system high frequency signal channel in multiple, the advantages of a control system above mentioned may be more readily appreciated.
  • a high frequency, tuned, .multi-stage amplifier is provided,
  • circuits employed are substantially like that shown in Fig. l and differ therefrom only to the extent that the circuits are adapted for multiple control of gain and of bias, together withcontrolled regeneration anode current, and further, with an electrode arrangement abovementioned, in which the first or inner grid is utilized as a control grid.
  • Each of the electric dischargedevices 31 and 38 is of the multiple grid type, having a heated cathode 39, a first or inner grid 40, a second grid 4
  • the tubes shown may be the usual pentode type of tube wherein the grids '42 are normally utilized as suppressor grids while the as screen grids.
  • Each of thedevices 31 and 3B in the stages 35 is provided with a tuned input circuit indicated at 44 in connection with theinner or first grid 40.
  • a suitable feed-back coupling means 45 or coupling coil is associated with the tuning grids 4! are utilized 4 inductance 46 for the-input orgrid circuit 44 and is provided with operating anode current through a resistor 41 in connection with a high potential supply lead 48, V
  • the low'potential side of the supply circuit is indicated at 49 and is the ground or low potential lead forthe receivingchannel and system.
  • cathode 39 is returned to this lead through a self bias;resistor-50, while the input circuit 44 is returned directly thereto through the lead 5l -I whereby self-biasgridpotentials are provided for thecontrol grid 40 from the resistor 50.
  • the output anode43-for the device 38 is connectedwithja succeeding stage or utilization device through an output circuit 52 in which is shown an'interstage coupling means comprising two windings 53and 54, providing inductive and capacitive coupling, respectively, with the input circuit 44 of the succeeding stage as shown. Anyother suitable coupling means maybe employed which provides for substantially uniform signal transfer over.
  • the second of the two stages shown is provided with anoutput circuit 55 which may be connected with any suitablecoupling means like that for the preceding; stage.
  • Suitable bypass capacitors indicated at 5 6' are provided in connection with the cathode, for the regeneration and input circuits and also-for .theouter or screen grid 42 of each of. the devices 3! and 38.
  • the latter "grids receive operating and control potentials through supply leads 5'! from the variablecontacts 58' of separate potentiometer means 59, each connected across thepotential supply leads 48 and 49 in parallel.
  • variable contacts 58 of the potentiometer devices 59 are 'a1so.connected for simultaneous gang operation as indicated by the'dotted connection 60 and the operating knob 6
  • the series resistor 41 in the regeneration anode circuit serves to prevent the regeneration current from rising when the screen grid potentials are reduced below a. predetermined value by operation of the potentiometer contacts 58. This is for the. reason that as the screen grid potential is reduced, the electrons from the cathode 39 tend to travel to the second grid orregeneration anode 4
  • The. impedance or resistor. 4! should provide a potential drop which is relatively high compared with the internal drop in the tube or electric discharge device itself, so that the impedance ,or resistor 41 serves effectively to control the regeneration current as the screen grid potential is varied.
  • the screen or outer grid potential is variable through the operation of the potentiometer means ing structure between the main output anode 43 and the auxiliary or regeneration anode means provided with the grid 4
  • is less than that of the first grid 40 so that in the circuit of the present example, as distinguished from that shown in Fig. 1,' the coupling for regeneration purposes with the input or grid circuit may be increased without overloading the regeneration circuit. This may be accomplished because of the higher impedance of the second grid 4
  • the normal current flow to the first grid 40 may be of the order of two to three milliamperes as com-pared to twenty to thirty milliamperes for the circuit of Fig. 1, wherein the first grid is utilized as the regeneration anode.
  • the electric discharge amplifier device employs a plurality of grid electrodes in addition to the usual anode and cathode, and that one of the grid electrodes serves as a screen grid structure between the main output anode and the auxiliary regeneration anode provided by another of the grid electrodes, while a third grid electrode is employed as a control grid for the amplifier device.
  • a regeneration coupling means is provided between the auxiliary anode electrode and the input circuit or control grid and independently of the regeneration adjustment the signal output or gain of the stage is then adjustable by varying the potential applied to the "screen electrode structure.
  • a relatively high gain per stage is effected and the regeneration effect and the resulting selectivity may remain substantially constant while the overall gainmay be controlled simultaneously in each stage as shown.
  • An impedance element in the regeneration anode circuit efie'ctively maintains a substantially constant mutual conductance at substantially all control positions of the gain control means.
  • the first amplifier stage 35 is supplied with signal energy through any suitable means such as a first stage amplifier device 02 whichis coupled through a suitable tuned input circuit 63 and coupling means i l of a signal collecting means indicated by an antenna 65 and a ground connection there for (it, the latter being a continuation of and connected with the low potential lead 09.
  • the amplifier device 62 may be of any suitable type and is in the present example provided with a cathode 61 having a self-bias resistor 63 in circuit therewith, a control grid 59 connected. with the input circuit 63, a screen grid '10 which receives operating potential from a tap H on the potentiometer 59 for the first amplifier stage 35 through a supply lead 12 and which is further provided with an output anode 13 also connected through an output M with the high potential supply lead 48.
  • this coupling means is provided by an electromagnetic coupling winding 53 associated with the input circuit inductance 56 and an electrostatic coupling winding 54 also associated therewith.
  • this coupling means is arranged in any suitable manner to provide substantially uniform transfer of energy throughout the signal range over which the amplifier is designed to operate.
  • a system embodying the invention may have the advantage or high selectivity and gain with controllable signal output adapted for multiple stage operation without efiecting the regeneration or selectivity and without involving the use' of additional electric discharge devices for that purpose.
  • the controlled regeneration may be applied to an oscillator having a pentode device having a cathode 16 of the heated type in the present example, a control grid H, a main output anode electrode T8, a
  • this embodiment of the invention employs the second grid 80 as an auxiliary or regeneration anode, and is connected through a coupling condenser ill to oneend 82 of an oscillatory circuit 83, while the opposite terminal 84 thereof is connected'to the control grid Tl through the usual grid leak and condenser combination indicated at 85.
  • the anode circuit for the grid electrodeBil is connected with any suitablesource of potential through a lead 80, in which is located a high frequency choke coil 81 providing the coupling impedance for the coupling condenser 8 I
  • the oscillator circuit is provided with the usual tapped grid-plate inductance 88 which is connected to a cathode return lead 89 through a lead 90.
  • the main output anode circuit for theanode i8 is indicated at 9
  • the screen grid structure 19 effectively surrounds the output anode 78 and is connected to the cathode lead 89 through a supply lead 92 and a variable source of biasing potentials provided by any suitable means, such as a battery 93 and a variable potentiometer device 94 connected in shunt thereto'with the variable contact 95 thereof connected with the supply lead 92.
  • the battery is provided with.
  • a center tap 96 which-is connected I 2,204,422 I to the cathode return leacl-89 through a grounded desired inthe low frequency end of the range, the
  • the oscillator is provided with a shield enclosure indicated at 98, which is also connected to the cathode return lead 83 and is arranged to cooperate, as indicated,
  • the oscillation frequency established in the generator circuit 83 is-substantially independent of the oscillation signal outputcircuit 9i and'the amplitude of the oscillations delivered to the circuit 9
  • a multiple g'rid'electrode electric discharge device and to employ the first or inner grid as the control grid, whilethe next adjacent or second grid is utilized as the feed-back or oscillation anode, and between these two electrodes any suitable oscillation generator circuit may'be provided;
  • the signal amplitude for energy may effectively be controlled combination, an electronic tube amplifier device between wide limits without afiecting the frequency setting cuit.
  • a fixed coupling has the advantagein certain amplifiers, such as a tuned high frequency amplifier shown in Fig. 1, that a sufiicient amount or regeneration is obtained at or inthe higher frequency end of the tuning or operating range of the system through'a proper degree of cou-- pling toprovide a desired selectivity efiect in this range Where the selectivity is ordinarily lower than at or in the low frequency end of the tuning or operating range of the system.
  • the invention is not limitedto theparticunal input :circuit connected between the cathode andone of said grid electrodes, means providing a regenerative feed-back coupling between another of said grid electrodes and said input circuit,'means for applying a positive potential with respect to cathode on said last-named electrode, means for applying a variable controlling potential to a. third grid'electrode more adjacent to the main outputanode, and a signal output circuit connected with said output anode.
  • an electric dis--- charge amplifying stage comprising an electric discharge amplifier device having a cathode, an anode, a control grid, a second grid adjacent "thereto and a-screen-grid adjacent to the anode,
  • a signal input circuit connected with the control grid, a signal output circuit connected with the anode, means providing a regenerative electrical coupling between the second'grid and said input circuit, andjmeans for applying operating potentials tosaid electrodes including a positive potential on said second-grid electrode less, than the anode potential and a variable potential on said'screen grid.
  • anelectricdis- I charge amplifying stage comprising an electric discharge amplifier device having av cathode, an anode, a control-grid,'a space charge gridand a screen grid adjacent to the anode, a signal input circuit connected with the control grid, a signal output circuit connected with the anode, means .providing a regenerative electrical coupling between the space charge grid and said input-circuit, means for applying a positive operating po tential' with respect to cathode to said space positive potential tosaid screen grid.
  • An, electric signal amplifier comprising in having a signal input electrode'and a-sig'nal out put electrode, ascreen electrode for said output electrode and an electrode providing a regeneration anode, means providing a regenerative electrical; coupling between said regeneration anode charge grid, and means forapplying a-variable mutual conductance with respect to the control f grid electrically coupled 'to said grid circuit to supply feed-back electrical energy thereto-for regeneration below the point, of oscillation, means in circuit with saidadditional electrode fer limiting currentflow thereto, and means for applying to the grid more adjacent to the anode a variable potential for controlling the mutual conductance of said device and the signal flow through said amplifier.
  • a radio signaling system including.
  • a plurality of cascade connected electric discharge amplifier stages each of said stages being electrically shielded and including an electric discharge amplifier device having a signal input circuit and a signal output circuit, means for coupling an electrode of said device other than an output electrode with said input circuit to provide regeneration, means for applying a varying gain controlling potential to another electrode of said device, and means for simultaneously operating each of said last named means in each stage.
  • a radio signaling system includingin combination, a plurality of cascade connected ampli bomb stages, at least one of which is shielded from another and each of which comprises an electric discharge amplifierdevice having a cathode and a signal input electrode, a signal output electrode, a screen electrode adjacent thereto, and an additional electrode, means providing a regenerative electrical coupling between said additional electrode and the input electrode at signal frequencies, current limiting means in circuit with said additional electrode, means forsupplying operating potentials to said screen electrodes, and means for simultaneously varying said last named potentials in each stage.
  • a radio signaling system including in combination, a plurality of cascade connected amplifier stages, at least one of whichis shielded from another and each of which comprises an electric discharge amplifier device having a cathode, a signal input electrode, a signal output electrode, a screen electrode therefor and an additional electrode, means providing a regenerative electrical coupling between said additional electrode and the input electrode at signal frequencies, current limiting means in circuit with said additional electrode, means for supplying operating potentials to said screen electrodes, and means for simultaneously varying said potentials in each stage, said last named means comprising a potentiometer device connected with said supply means and having a variable tap point connected with one of said screen electrodes.
  • an electric discharge amplifying stage comprising an electric discharge amplifier device having a cathode, an anode, a control grid, a screen grid and a suppressor grid, a signal input circuit connected with the control grid, a signal output circuit connected with the anode, means providing a regenerative electrical coupling between the screen grid and said input circuit, means for applying a positive operating potential with respect to cathode to said screen grid, and means for applying a variable controlling potential to the suppressor grid.
  • an-electric discharge device having a cathode, an anode, a control grid, a grid structure adjacent to the anode and an auxiliary anode electrode interposed between said grid structure and the cathode, means providing regenerative feed-back coupling below the point of oscillation between the control grid and the auxiliary anode electrode, a signal input grid circuit connected with said control grid, an output circuit connected with said first named anode, and means for applying a variable potential to the said grid structure whereby the electrical output through said output circuit may independently be varied.
  • a radio signaling system including in combination, a plurality of cascade connected electric discharge amplifier stages, each of said stages being electrically shielded and including an electric discharge amplifier device having a signal input circuit and a signal output circuit, means for coupling an electrode of said device other than an output electrode with said input circuit to provide regeneration, and means for applying a variable gain controlling potential to another electrode of said device.
  • An electric tube amplifier system including in combination, a signal input grid circuit, a regenerative feed-back circuit coupled to said input circuit, a suppressor grid circuit, and means for supplying a variable controlling potential to said suppressor grid circuit.
  • an electron discharge amplifier circuit comprising in combination, a tunable signal input grid circuit, a screen grid potential supply circuit regeneratively coupled to said grid circuit, a suppressor grid potential supply circuit, means in said last named circuit for Varying the potential of said circuit,
  • an electron discharge device having a cathode, an anode, a control grid, a screen. grid, and a suppressor grid between said cathode and anode, of a signal input grid circuit connected with said control grid, means including said input grid circuit for regeneratively coupling said control grid and screen grid, a signal output circuit connected with the anode, and means for variably controlling a potential on said suppressor grid to variably control the amplitude of signals applied to said output circuit.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
US678406A 1933-06-30 1933-06-30 Radio signaling system Expired - Lifetime US2204422A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US678406A US2204422A (en) 1933-06-30 1933-06-30 Radio signaling system
FR773703D FR773703A (fr) 1933-06-30 1934-05-26 Perfectionnements aux systèmes de radio-signalisation
DER90922D DE645177C (de) 1933-06-30 1934-06-30 Rueckkopplungsschaltung fuer Hochfrequenzanordnungen
GB19511/34A GB426109A (en) 1933-06-30 1934-07-02 Improvements in or relating to thermionic valve circuit arrangements for use in highfrequency signalling systems

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Application Number Priority Date Filing Date Title
US678406A US2204422A (en) 1933-06-30 1933-06-30 Radio signaling system

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Publication Number Publication Date
US2204422A true US2204422A (en) 1940-06-11

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US678406A Expired - Lifetime US2204422A (en) 1933-06-30 1933-06-30 Radio signaling system

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DE (1) DE645177C (de)
FR (1) FR773703A (de)
GB (1) GB426109A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2721977A (en) * 1951-05-09 1955-10-25 Gen Electric Variable amplitude oscillator
US2745909A (en) * 1951-03-08 1956-05-15 William B Anspacher Screen-grid neutralized amplifier

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1011943B (de) * 1954-11-09 1957-07-11 Wilhelm Blank Dipl Ing Hochfrequenzverstaerkerstufe, insbesondere fuer Rundfunkempfaenger

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2745909A (en) * 1951-03-08 1956-05-15 William B Anspacher Screen-grid neutralized amplifier
US2721977A (en) * 1951-05-09 1955-10-25 Gen Electric Variable amplitude oscillator

Also Published As

Publication number Publication date
FR773703A (fr) 1934-11-24
GB426109A (en) 1935-03-27
DE645177C (de) 1937-05-22

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