US1956582A - Radio receiving and transmitting apparatus - Google Patents

Description

y 1934- 'r. A. MARSHALL 1,956,582

RADIO RECEIVING AND TRANSMITTING APPARATUS Filed Dec. 3, 1929 4 Sheets-Sheet 1 AP 9 7H WI} hllhlllmm 43 I g 42 4/ Thomas A. Mars/1a INVENTOR ATTORNEY May 1, 1934. T. A. MARSHALL RADIO RECEIVING AND TRANSMITTING APPARATUS Filed Dec. 5, 1929 4 Sheets-Sheet 2 Thomas A. Mars/2a INVENTOR CJ flaw ATTORN EY y 1934- 'r. A. MARSHALL ,5

RADIO RECEIVING AND TRANSMITTING APPARATUS Filed Dec. 3, 1929 4 Sheets-Sheet 5 9 f b l3 4 f 8 m n M l- \i 7 H 18 Thomas A.Mar5/7al1 )5 INVENTOR 3 A i We ATTORNEY l, 1934. 'r. A. MARSHALL 1956582 RADIO RECEIVING AND TRANSMITTING APPARATUS Filed Dec. 3, 1929 4 Sheets-Sheet 4 r a 6 F V 26 V )1 AL I6 I 15 A! I 6 Mg as F]: J T 18 I'll Thoma; A. Mam/1a?) 27 lNVENTOR BY fl|l|85ll|ill W W 2 22 ATTORNEY Paras FFE RADIO RECEIVING AND TRANSMITTING APPARATUS Thomas Aibert Marshall, United States Navy Application December 3, 1929, Serial No. 411,318

16 Claims. (Cl. 179-171) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 O. G. 757) My invention relates broadly to radio receiving ordinary three element tubes are employed and and transmitting circuits and more specifically a novel balance system is provided. to a circuit arrangement for a push-pull, radio Figure 1 comprises a push-pull radio frequency frequency amplifier as applied to receiving and amplifier circuit in which 1 represents the antransmitting circuits. tenna, and 2 and 3 the antemia coupling coils. GO 5 One of the objects of my invention is to pro- The numeral 4. is a split condenser having its vide a system for receiving and transmitting radio two halves in series and respectively connected signalling energy, in which the total effective tube to the grids or control electrodes 11 and 15 of capacity on the tuned input circuit is substanthe two tubes 7 and 8, through grid condensers tially lowered. 5 and 6. The center connection of the split con- 10 Another object of my invention is to provide denser is connected to the filament or cathodes a circuit having a high degree of symmetry, and 12 and 16 of the tubes '7 and 8, and may be therefore peculiarly adapted to a variety of uses grounded as at 44 if desired. It is seen that each as, for example, for use in connection with a digrid to filament capacity is across one of the rectional loop. halves of the split condenser. The total effec- 70 Still another object of my invention is to protive tube capacity is thus halved. It is to be vide a radio frequency amplifier circuit having noted that the two grids to filament circuits are a relatively high L/C ratio. each across half of the tuned circuit input voltage A further object of my invention is to provide which decreases the grid to filament energy disa push-pull circuit in which there is no direct sipation to one quarter of the amount for a sin- 7 center connection to the coils in the grid circuit, gle tube across the full voltage.

these coils being permitted to find their own eleo- Using the split condenser gives an advantage trical center, which may be different from the apover the usual push-pull circuit in that no cenparent center due to electrical irregularities in ter connection is need for the grid coil 3. This the circuits and tubes. coil is permitted to find its own electrical center 86 Other and further objects of my invention will which may be diiierent from the apparent cenappear more fully hereinafter as the descripter due to electrical irregularities in the circuits tion of the method and apparatus is developed. and tubes. The circuit thus helps to preserve lT fy invention consists substantially in the conthe electrical symmetry which is essential to efstruction, combination, and arrangement of parts ficient and stable operation and also permits a 30 associated therewith or as will be more fully high ratio WhiCh is particularly desirable at h i fte set forth as shown by the accomhigher frequencies, as it results in the desired panying drawings and finally defined in the apfrequencies being spread overa larger range of l condenser settings, thus making the tunlng of pended claims.

to be to assassinstars; if. 90 drawings forming a part of this specification in which like characters indicate corresponding Waves from Say one to thlrty metels long In the circuit shown in Figure 1 two high inparts throughout the several views and in \Vnl-1 ductance 10w capaclty chokes 24 and 25 are com Flgure q a raldw frequgncy m nected to the plates 13 and 9 of the tubes 8 and 40 clrcmt mcludmg 9 condense? m '7 respectively, and in series with each other. A the grid circuit in accordance with my invention; third and similar choke 23 is connected t0 the Figure 2 is an improveddetector Circuit junction of the two plate chokes and in series bodyins the elements of my invention; with the B battery 22. This additional or third Figure 3 is a circuit with the circuits of Figure choke Serves the purpose of isolating the jun tion 451 and Figure 2 combined and a stage of audio of th t plate hokes from the ground potenfrequency amp fi tio added thereto; tial. This permits of the chokes finding their Figure 4 ShOWS y invention p d to a radio own electrical center which may be different from compass circuit; the apparent center due to electrical irregularities Figure 5 shows my invention adapted to a of the circuits and tubes. This, with the arrange- 'tra m tt circuit; ment in the input circuit, helps preserve electri- Figure 6 is a modification of Figure 1 with a cal symmetry. The battery 21 regulated by recondenser shunting the coils in the plate cirsistance 20 serves to heat the filaments 12 and cult; and 16. Grid leak resistances l7 and 18 are con- Figure 7 is a modification of Figure 1 in which nected across the grids, their junction being connected to the filaments through resistance 20. The screen grids, 10 and 14, are connected to a suitable point on the B battery 22 and to the ground through condenser 19. The output is connected through condensers 26 and 27 to the coil 29 of the detector circuit shown in Figure 2. a

In the circuit shown in Figure 2, the tuning condenser 30 is similar to that employed in the amplifier circuit. The push-pull arrangement of the two detector tubes 36 and 37 again permits electrical symmetry and a high L/C ratio,

Coil 29 is connected to the grids 39 and 42 through grid condensers 31 and '32. Grid leak resistances 33 and 34 are connected across the grids, their junction being connected to the filamerits 40 and 43 through resistance 35.

The tickler feed-back inductance coil 28 is tapped in the center and connected to the plus B battery 22 terminal through a radio frequency choke 49, the head phones 50' and the variable resistance 46 which is shunted by condenser 4'7.

Battery 21 heats the filament.

Regeneration may be controlled by Varying the direct current voltage on the plate elements 38 and 41 of the two detector tubes 36 and 37.

Figure 3 is a'combination of the circuits of Figures 1 and 2. The detector circuit and the radio frequency amplifier are in individual shielded compartments. The two are coupled by the two condensers 26 and 27 which aresmall enough to prevent undesired reaction of the circuits. In this circuit a stage of audio frequency amplification is shown coupled through transformer 48. The numeral 51 is a tube having the grid 53, the plate 52 and the filament 54 which is connected to the battery 55 through the resistance 57. B battery 56 furnishes the plate voltage.

Figure 4 is diagram showing the push-pull amplifier adapted to a radio compass coil. This is an improvement over the single tube stages due to the perfect electrical symmetry obtained. In the single tube circuits, the most common cause for the destruction of the null point is due to the antenna effect which is caused by the electrical dissymmetry of the radio compass circuit. If one side of the loop is connected to the grid, while the other side is connected to the filament which i is common to all the battery circuits, giving high ground capacity, an electrical dissymmetry exists on account of the unequal capacities to ground of the two loop connections. This unbalancing of the circuit permits the coil to function additionally as an antenna circuit. For this reason, when the a coil system is at right angles to the direction of the propagation of the electro-magnetic wave, there is an indirect current in the circvut which is due to the coil as an antenna. The circuit in Figure 4, due to perfect electrical symmetry, eliminates all antenna efiects which permits a sharp point of silence to be obtained. In this circuit, 1 is the coil antenna, 4, the split condenser connected through grid condensers 5 and 6 to the grids 11 and 15 or the tubes '7 and 8 respectively. Grid leak resistances l7 and 18 areconnected through resistance 58 to the filaments l2 and .16. The battery 21, through resistance 20, furnishes the filament current. The B battery 22 together with the plates 9 and 13 form the intra-electrode capacity obtained in the receiving circuit of course are present in this transmittin circuit. In this circuit the coil 63 which receives the input is connected to the grids 72 and 75' of the tubes 69 and '76 through the grid condensers 65 and 66 respectively. The split condenser 64 performs he same function as condenser 4 does in Figure 1. The center electrode of condenser 64 may be grounded as at 59 if desired. The filaments 73 and 76 are heated from an alternating current source 80, connected through transformer 79. shunted across the secondary of this transformer are two condensers 7'7 and 78 connected in series. The mid-point of the secondary is connected to a point between these two condensers and to the rotor of the split condenser 64. Two radio frequency chokes 67 and 68, connected in series, -are placed across the grids 72 and 75. The mid-point of the secondary of transformer 79 is also connected to a point between these two chokes. The plates 71 and 74 of the tubes are connected through coupling coils 82 and 33 to the antenna 84. The mid-point of coil 82 is connected to the plus plate voltage source through radio frequency choke 81, the negative of this source being connected to the mid-point of the transformer 79. tuning condenser 86, with the ammeter 85 in series therewith, is shunted across the plate circuit.

Figure 6 shows a circuit identical with that shown in Figure 1 except that the output plate circuit has been modified by the substitution of the circuit containing the capacity 61 and inductance 62, for the coils 24 and 25 permitting a high plate load impedance, which gives greater signal strength than the circuit shown in Figure 1.

Figure 7 is a circuit similar to Figure 1, except that three element tubes are used instead of four element tubes. In this circuit balancing condensers 59 and 60 are connected between plate 9 and grid 15, and plate 13 and grid 11 respectively. This criss-cross balancing condenser arrangement could also be used in Figure 1 if desired but is not necessary.

It will be understood that the above description and accompanying drawings comprehend only the general and preferred embodiments of my invention and that minor detail changes in the construction and arrangement of parts may be made within the scope of the appended claims without sacrificing any of the advantages of my invention.

The invention herein described may be manufactured and used by or for the Government of the United States without the payment to me of any royalties thereon or therefor.

Having described my invention, what I claim is:

1. A signal circuit including a single coil and a condenser in parallel to form a tunable circuit, said condenser having more than two plates, one of the plates of the condenser being positioned at the mid-point of the potential gradient across said condenser, a pair of vacuum tubes, each having a cathode, anode, control electrode and screen grid electrode, the cathodes of said tubes being connected to the plate which is positioned atthe midpoint of the potential gradient, the control electrodes of said tubes being connected to other plates in said condenser, and a capacity connecting the cathodes of said tubes to the screen grid electrodes of said tubes whereby said tuned circuit and the screen grid electrodes of said tubes are maintained symmetrical with respect to the cathodes of said tubes.

2. A signal circuit including a single coil anda condenser in parallel to form a tunable circuit, said condenser having more than two plates, one of the plates of the condenser being positioned at trodes, a circuit connecting the cathodes of said necting each of said screen grid electrodes through loop antenna, a tuning condenser having two the mid-point of the potential gradient across said condenser, a pair of vacuum tubes, each having a cathode, anode, and control electrode, the cathodes of said tubes being connected to the plate which is positioned at the mid-point of the potential gradient, the control electrodes of said tubes being connected to the terminals of said coil, and a resistance connecting each control electrode to the cathode of said tubes.

3. A signal circuit including a single coil and a condenser in parallel to form a tunable circuit, said condenser having more than two plates, one of the plates of the condenser being positioned at the mid-point of the potential gradient across said condenser, a pair of vacuum tubes, each having a cathode, and control electrode, the oathodes of said tubes being connected to the plate which is positioned at the mid-point'of the potential gradient, the control electrodes of said tubes being capacitatively connected across said coil, and resistances of like value connecting the control electrode of each tube to the cathode of each tube.

4. A signal circuit including a single coil and a condenser in parallel to form a tunable circuit, said condenser having more than two plates, one of the plates of the condenser being positioned at the mid-point of the potential gradient across said condenser, a pair of vacuum tubes each having cathode, anode, control and screen grid electubes being connected to the condenser plate which is positioned at the midpoint of the potential gradient, connections between the control electrode and terminals of said coil, a circuit cona capacity to the last mentioned condenser plate, and a balanced repeater circuit connected between the anodes of said tubes.

5. A radio receiving circuit comprising a single plates, one of which is connected to one terminal of said loop, the other plate being connected to the other terminal of said loop, means for balancing said loop with respect to ground including an element located between said plates and connected to ground, two thermionic repeater devices, each including an anode, cathode, and a control electrode, the control electrodes being connected to opposite plates of said tuning condenser and the cathodes being connected to ground and to the element located between the plates of said condenser, and a work circuit connected between said anodes.

6. In a balanced thermionic relay device, a pair of thermionic tubes each having anode, cathode ture to the cathodes of said tubes, a symmetrical circuit including a source of potential connecting the anodes of said tubes to the cathodes of said tubes, and means for impressing signal energy on said first named inductance.

7. A relay, as claimed in claim 6, in which the control electrode of one tube is capacitively coupled to the anode of another tube.

8. A thermionic translater including a plurality of thermionic tubes each having anode cathode and control electrodes, means for impressing cscillations on said control electrodes comprising an inductance shunted by a condenser having two sections formed by a common armature and two isolated armatures, the common armature being connected to the cathodes of said tubes, the terminals of said inductance being connected to the control electrodes of said tubes and to said isolated armatures, a symmetrical output circuit including an inductance and a parallel condenser connected between the anodes of said tubes, a second inductance connecting the midpoint of said last named inductance through a source of potential to the cathodes of said tubes, a utilization circuit comprising an inductance, a

circuit connecting each terminal of said inductance to the anode of one of said tubes, and means for tuning said inductance and for balancing said utilization circuit with'respect to ground comprising, a condenser having two sections formed by a common armature and two insolated armatures, the common armature being connected to the cathodes of said tubes, and the terminals of said last named inductance being connected to the isolated armatures of said condenser.

99. Ultra high frequency relaying means comprising, a plurality of pairs of thermionic tubes, each tube having anode, cathode and control grid electrodes, means for impressing oscillations to be relayed between the control grid and cathodes of one of said pairs of tubes comprising, an inductance having one terminal connected to the control grid of one of the tubes of said pair and its other terminal connected to the control grid of the other tube of said pair, means for tuning said inductance and balancing the same with respect to the cathodes of the tubes of said pair comprising, a capacity connected in parallel with said inductance, an additional element in said capacity located between the terminals thereof, a circuit connecting said additional element to the cathodes of said tubes, a symmetrical output circuit connected between the anodes of said pair of tubes, and means for coupling said output circuit to the control grids of another pair of tubes comprising, an inductance, a capacitive connection between each terminal of said inductance and the anode of one of said tubes in said first named pair, a connection between each terminal of said inductance and the control grid of a tube in said second named pair, and means for tuning said inductance and balancing same with respect to the cathodes of the tubes in said second named pair comprising, a capacity connected in parallel with said inductance, and an additional element located between the terminals of said capacity and connected with the cathodes of the tubes in said second named pair.

10. A radio receiving circuit comprising a loop antenna including one or more turns of conducting material, a tuning condenser having two armatures, one of which is connected to one terminal of said loop, the other armature being connected to the other terminal of said loop, means for balancing said loop with respect to ground including an element located at the midpoint of the potential gradient between said aforesaid armatures and connected to ground, a pair of thermionic repeater devices, each device including an anode, cathode, and a control electrode, a connection between the control electrode of one of said tubes and one of said armatures of said tuning condenser, a connection between the control electrode of the other of said tubes and the other armature of said tuning condenser, a connection between the cathodes of each of said tubes and groundand the element located between said condenser armatures, and means for connecting a work circuit. between the anodes of said tubes.

11. In a thermionic relay device, a pair of thermionic tubes, each having anode, cathode and control grids, and means for applying potentials to the control grids of said tubes comprising, an inductance having one terminal connected to the control grid of one of said tubes and the other terminal connected to the control grid of the other of said tubes, and means for tuning said inductance to the frequency of the potentials applied to the control grids and for balancing said circuit including said grids with respect to ground comprising, a capacity element having two sections made up of a common armature cooperating with a pair of isolated armatures, one of said isolated armatures being connected to one terminal of said inductance, the other of said isolated armatures being connected to the other terminal of said inductance, said common armature being connected to the cathodes of said tubes and to ground, a load circuit connected with said anodes, and means for preventing said load circuit and said anodes from reacting on said control grids and associated circuits including an auxiliary electrode interposed between the anode and control grid of each tube.

12. A device as recited in claim 11 in which' said load circuit is capacitively coupled to said anodes.

13. A balanced amplifier circuit comprising a plurality of coacting amplification stages, each stage comprising a pair of electron tubes, said electron tubes comprising a cathode, a control grid, an anode and a screen. grid, an input circuit for one pair of said tubes comprising an inductance, a tuning condenser having three plate systems, a connection between one plate system and one end of said inductance, a connection between another of said plate systems and the other end of said inductance, said connections forming a closed tunable path, a pair of condenser units,

one of said condenser units being disposed in series between a control grid of one of said electron tubes and one end of said tunable path, a connection between the control grid of the other of said electron tubes and the other end of said tunable path, a connection between the otherof said plate systems and said cathodes, a pair of separate resistor elements, said elements being connected in common at one end thereof, a connection between the control grid of one of said electron tubes and one of said resistors, a connection between the control grid of the other of said electron tubes and the other of said resistors, means connecting the cathodes of said tubes with the common connection between said resistors, a tuned circuit comprising an inductance shunted by a condenser, one end of said tuned circuit being connected with the anode of one of said electron tubes and the other end of said tuned cir cuit being connected with the anodeof the other of said electron tubes, an electrical connection between the screen grid electrodes of each of said electron tubes, and means for applying predetermined potentials to said cathodes, said screen grid electrodes and to said anodes.

14. In a high frequency amplifier, a pair of electron tubes each including a cathode, a control grid, an anode and a screen grid, a common circuit for energizing said cathodes, a common connection between said screen grids, a tunable circuit having one end connected with the anode of one electron tube and having the other end connected with the anode of the other of said electron tubes, a source of potential connected between said cathodes and a point in said tunable circuit, a connection between said source of potential and the common circuit interconnecting said screen grids, an inductance, a pair of independent condensers, a connection between one end of said inductance through one of said condensers to the control grid of one electron tube, a connection from the other end of said inductance to the other of said condensers with the control grid of the other of said electron tubes, a three-electrode condenser system having one'electrode connected with said cathodes, one electrode connected with one end of said inductance and the other electrode connected with the opposite end of said inductance, a resistance unit connected between said control grids, a tap intermediate the ends of said resistance unit, a variable resistor connected with said cathodes, and a connection between said variable resistor and the tap on said resistance unit.

15. An ultrahigh frequency amplifier system comprising a pair of balanced electron tubes, each including a cathode, a control grid, a screen grid and an anode, a tuned circuit interconnecting said control grids, a tuned output circuit connected with said anodes, a potential source for energizing said cathodes, and said anodes, a conductor interconnecting said screen grid electrodes, a connection between said conductor and said source of potential, and a condenser connected between a midpoint along said conductor and said cathodes.

6. An ultrahigh frequency amplifier system comprising a pair of balanced electron tubes, each including a cathode, a control grid, a screen grid and an anode, a tuned circuit interconnecting said control grids, a tuned output circuit connected with said anodes, a potential, source for energizing said cathodes and said anodes, a conductor interconnecting said screen grid electrodes, a connection between said conductor and said source of potential, and a large capacity condenser forming a low impedance path to ultrahigh frequency currents symmetrically connected between said conductor and said cathodes.

THOMAS ALBERT MARSHALL.

Images