US2245645A - Radio signaling system - Google Patents

Description

June 17, 1941. 'E. L. BRQWQ 2,245,645

RADIO SIGNALING SYSTEM Filed April 13, 1940 6 Sheets-Sheet l I W I INVENTOR f/mer Z. firown ATTORNEY June 17, 1941. L bw RADIO SIGNALING SYSTEM Filed April 13, 1940 6 Sheets-Sheet 2 R O Y W W E5 R V 0 m vw r MA m Y B.

FIE EEI a 7 June 17, 1941. E, L, BROWN 2,245,645

RADIO SIGNALING SYSTEM Filed April 13, 1940 6 Sheets-Sheet 3 INVENTOR f/mer Z. fir'own ATTORNEY June 17, 1941. BROWN 2,245,645

7 RADIO SIGNALING SYSTEM Filed April 15,, 1940 6 Sheets-Sheet 4 INVENTOR f/mer L. Brown ATTORNEY Gil/em 4 June 17, 1941. E. L. BROWN 2,245,645.

RADIO SIGNALING -SYSTEM Filed April. 13, 1940 e Sheets-Sheet 5 f/mer l. Brow/7 ATTORNEY June 17, 1941. E. L. BROWN i 2,245,645

RADIO SIGNALING SYSTEM V 7 Filed April 13, 1940 I 6 Sliegts-Sheet 6 INVENTOR [//77@/' L firown ATTORNEY Patented June 17, 1941 RADIO SEGNALING SYSTEM Elmer L. Brown, San Francisco, Calif., assignor to Joseph B. Smith, San Francisco, Calif, as

trustee Application April 13, 1940, Serial No. 329,479

Claims.

This invention relates generally to radio signaling systems making use of ultra high frequency radio energy, as for example energy of the order of from 100 to- 400 megacycles. Features of the invention are applicable to both receiving and transmitting equipment.

It is an object of the invention to provide apparatus of the above character capable of increasing the effective distance over which one may successfully communicate witha given minimum amount of available power. object of the invention is to provide radio equipment capable of manufacture in compact form so as to be readily portable together with the required power supply.

Another object of the invention is to provide radio means capable of stable operation at ultra high frequencies with a'minimum amount of interference and disturbing background noises, and without serious fading of a character such as is frequently characteristic of short wave radio equipment. p

Another object of the invention is to provide a novel short wave receiver which is capable of hypersensitivity far beyond that made possible by the use of conventional super-regeneration, and which is also stable and relatively free of interference and disturbing background noises.

Another object of the invention is to provide a novel form of oscillator for use in conjunction with ultra high frequency radio transmitting equipment, and characterized particularly by its stability of frequency and 'by"itsabi1ity to be assembled in compact form for portable use.

Additional objects and features of the invention will appear from the following description in which the preferred embodiments of the invention have been set forth in detail in coniunc tion with the accompanying drawings.

Referring to the drawings- Figure 1 shows a radio receiving circuit incorporating thepresent invention,

Figures la, 1b and 1c are circuit diagrams Figure 3 shows a short wave radio. transmitter circuit incorporating the invention; 7

Figure 3a is a circuit diagram illustrating a possible modification to the transmitter illustrated in Figure 3; r

A further receiver and transmitter Figure 4 is a circuit diagram showin a modiv fied form of a short wave transmitter, while Figure -5 is a cross sectional view, in diagrammatic form, illustrating-how the transmitter of Figure 4 canbe incorporated into a structural assembly; s

Figure 6 shows a modified form of radioreceiving circuit incorporating the invention;

Figures 7 and 8 show, radio transmitter and receiver circuits respectively incorporating the inventionand making use particularly.- of conductive hemispheres forming a part iofgthe inductance elements; M Figure 9 is a circuit diagram showing a radio-- interconnected r by; switching. means for two way communication; and Figure 10 is a circuit diagram showing a; radio transmitter and freceiver interconnected for -two way radio communication upon different fre quencies, without a change-over switch.

The circuit illustrated in Figure 1 is for the, reception of ultra high frequency signal energy and is suitable for'incor-porationv in a small portable telephone receiver.- The circuit includes a vacuum tube detector ID, or electron ,relay,;ha ving the conventional cathode, plate and control ele'-- ments ll, l2 and L3. Thistube may be: one} available on the open market, such as type,6- G 5- made by Radio Corporation of America- The cathode is shown connected'to the A battery: 14..

A tuned circuit connects across the plate and control elements 12 and I3, and this circuit in:- cludes the inductance l6 shunted by the variable condenser ll, whereby the inductance is'sharply 'tunedto the frequency of' the signal energy.

One terminal'of inductance It connects directlywith plate l2, while the other terminal connects with the'grid or control element l3 through the grid condenser l8'and grid leak I9; l

The antenna 2| can be a straight rod of conductive material, having a lengthcorresponding generally to one-quarter wave length. One end of this antenna is reactively coupled to the tuned circuit just described; Preferably this" coupling is through a relatively'small variable condenser '22, which in turn connects directly to. the grid control element I3. As will be presently explained, the receiver is critical .tov the adjust ment of the condenser 22. I

The detector tube It] is coupled to .an'zamplifier, including the vacuum tube 'llla, through the: audio frequency transformer 24. The primary of 1 transformer 24 has one terminal iconnected'ft'o the positive side .of B battery :26,-andthe.negative 'side of this battery is connected to the cathode? I I. The other terminal of the primary of transformer 24 is connected to one side of an inductance 21, the other terminal of which is connected by a conductor 23 with the mid point of inductance l6. Inductance 21 is shunted by a pair of serially connected condensers 29 and 30. Condenser 29 is relatively large in capacitance compared to condenser 30, as for example a capacitance of 0.006 m. m. f. in contrast with 0.0001 m. m. f. capacitance for condenser 30. These capacitance values are suitable for a receiver operating over a range of from 165 to 225 megacycles, with the inductance 21 consisting of from 25 to 30 turns of No. 24 wire, wrapped upon a cylindrical forrm one-quarter inch in diameter. The connection between condensers 2 9 and 30 is connected by conductor 25 to the cathode II. The tuned circuit formed by inductance 21 together with condensers 29 and 3D is in resonance with a. supersonic frequency substantially less than the ultra; high frequency of the signal energy to be received, as for example a frequency of the order of 11 megacycles. The smaller condenser 30 acts mainly as a tuning condenser, while condenser 29 because of its higher capacitance acts as a by-pass.

Closely coupled to that end of inductance 21 which is connected to tuned inductance I6, there is an open ended loop 3|, formed for example by athree-quarterturn of wire disposed relatively close to the coil forming inductance 21. One end of this loop connects to the cathode I I.

The amplifying means connected to the secondary of transformer 24 may be more or less conventional in character. As illustrated, the vacuum tube Illa. is a pentocle, having its grid or control'element 32 connected to one side of the secondary of transformer 24. The other side of the transformer secondary connects through the grid leak 33a and grid condenser 33b, to the cathode 34. The amplifier output transformer 35 has its primary connected to the plate 36, and the tube element 31. The tube element 38 or screen is connected to the cathode 34. The positive side of B battery 26 also connects in series with the primary of transformer 35 and plate 36. The secondary of the transformer 35 is shown operating the loudspeaker 35a.

The circuits associated with the detector tube l3 should be properly shielded as is well known to those skilled in the art. In additionto, or as a part of such shielding, I have found it desirable to use a conductive plate 39 disposed equidistant from each of the external terminals of the vacuum.

tube ID, or from the terminals of the socket in which the tube is mounted. The object of such a plate is to afford small but equal supplemental capacitance values between the relatively neutral point of potential represented by the plate and each terminal of the elements of thetube. Such small capacitance values appear to be beneficial in operation'of the receiver as will be presently explained, and they supplement the internal and direct capacitance between the .cathode, plate: and control elements. For a receiver as described above, it is practical to locate the plate 39 about one-quarter inch from the socket terminals. Figure 'ld illustrates the arrangement diagrammatically. Plate 39 need not be grounded. Figure 1b shows an arrangement which can be used in place of Figure 1a, but'with results not deemed to be so effective. In this case, tube It] is provided with a metal base ring 39a which surrounds but is capacitatively spaced from the inner parts of the tube elements. A further conductive plate 39?) is located adjacent the tube and may be disconnected entirely or connected to one side of the cathode. Plate 39b represents a point of relatively neutral potential which is capacitatively associated with ring 3Sa, the value of the relation being adjustable by moving the position of the plate.

The receiver described above possesses several novel characteristics, including its ability to operate under conditions of hypersensitivity. Adjustment of the receiver to obtain the desired hypersensitivity is obtained by changing the value of the antenna coupling condenser 22. This condenser is relatively small, and for values previously stated byway of example, the condenser may be capable of continued variation from a maximum value of say 4 m. m. f. to a value of less than 1 m. m. f. When condenser 22 is of the order of say 2 m. m. f., the receiver is capable of super-regeneration, in that there is a regenerative action coupled with; the generation of a supersonic quenching frequency corresponding to the frequency to which inductance 21 is tuned. Conventional super-regeneration is well known to those skilled in the art, and need not be described in detail. If one further reduces the capacitance of condenser'22, a value is reached at which the circuit clicks or"plops from a condition of conventional super-regeneration, into what I [have termed a condition of hypersensitivity in which it functions as a true negative resistance. During normal super-regeneration, the plate current for the detector tube ID in a typical instance will be of the order of 2.5 milliamperes for a B battery potential of volts, and in general the value of condenser 22 is aminor fraction (such as 10% of the value suitable for conventional superregeneration.

For a condition of conventional super-regeneration, there is a noticeable hissing together with other disturbing and interfering background noises. When adjusted for a condition of hypersensitivity, such hisses and background noises disappear substantially completely, the tuning becomes sharper without being too critical, there is a noticeable increase in fidelity of reproduction when operated upon radio telephone signals, and incoming signals become noticeably louder. In addition, the receiver becomes extremely stable so that body capacitance and surrounding metallic objects have negligiblev effect upon sensitivity or frequency of operation. The sensitivity is so great that evenwith a fraction of a watt being transmitted from a remote radio telephone installation, signals can be heard clearly without distortion through large physical obstructions, through conductive material such as steel or salt water, and under normal conditions for distances of ten miles or more;

The loop 3| appears to play a material part in securing the desired sensitive operation with stability and suppression of background noises. I attribute this in part to an acceleration in the transit time for electrons in tube IO, which is obtained by energy exchange between loop 3| and inductance 21. This energy exchange is in. the nature of positive voltage from the cathode to inductance 2'! and the plate circuit. It will be noted that the reactive coupling obtained by the relationship between loop 3i and inductance 21 is mainly capacitative, but because capacitance is. distributed the length of the loop, there is also some inductive coupling. Also in contrast with conventional regeneration, coupling 22 is so small as to have negligible; elfect upon the frequency of operation. 1

A further characteristic. of the above circuit is the type which generate a quenching frequency in the detector circuit, it is customary to provide the primary of the output transformer with a shunt condenser, whereby the primary of the transformer is tuned to the supersonic quenching frequencies. Although in the present instance the primary of the transformer 24' may have a natural period corresponding to a supersonic frequency, this resonant circuit is not completely excited to an extent sufficient to. cause such a frequency to be generated, but instead the'circuit formed by inductance 21 with condensers: 29 and 30 is excited for generation of. the desired supersonic frequency. V

The capacitator plate 39, or the alternative arrangement of Figure 1b, appears to materially contribute to proper results. According to my observations, the small supplemental capacitances afforded between the tubeelements and plate 39 serve as a part of neutralizing means which in conjunction with the loop 31, neutralize. out inductive reactance of the tube elements and. provide a minimum input impedance for the receiver. This in. turn facilitates operation. under the desired condition of hypersensitivity previously described, since the neutralizing action makes possible operation of the circuit with minimum energy dissipation and at maximum sensitivity.

Reference has been made to suitable values for inductance 21, and condensers: 29 and 30. By way of example, the otherelements of the circuit can have valuesas follows: Inductance l6 may consist of from 3 to 5- turns ofNo. 14 wire wound as a helix about a form 1% inch in diameter. Condenser I! can have a maximum value of 15 m. m. f. Condenser I8 and resistor l9 can have values of .0001 m. f. andv 5 megohms respectively. Transformer 24 can have a primary impedance of 7500' ohms and a secondary impedance of 100,000 ohms.

Figure 1c shows a possible modification of Figure 1. Radiov frequency chokes I40.v are inserted between the cathode terminals andA battery l4, and loop 3| connects between resistors l4b, which in turn are in series and connected across the cathode terminals. Resistors Mb can be of the order of 3500 ohms each.

The embodimentof Figure 2 is a'receiver similar to that of Figure 1, except that the circuit which includes the tuned inductance l6 also includes certain capacitive elements, andthe detector tube 40 makes use of a cathode Ha, together with a heater lib. Thus, threefconductive elements 4!, 42 and 43-are provided which for the frequency range of operation previously indicated may consist of metal discs about inch in diameter, with discs 4| and 42 spaced. apart about 1% of an inch by suitable insulation such as Myca-lex" and discs=42r and 43' spaced apart about 0.005 inch,,with a dialectric such as mica. Disc 4| connects to that. terminal of inductance I6 which is also connected to the plate [2; Disc 42 connects to the other terminal of inductance 16. Disc 43 connects to the-grid or control element, I3, and also through the adjustable grid leak 44 to the cathode l-la.

The receiving circuit shown in Figure 2 is capable of operating in substantially the'same manner as the circuit of Figure 1. However, the

grid leak. 44 requires adjustment for the proper operating point. For'the' values and for the range,

of frequencies previously specified, this will-be in the neighborhood of from 50,000 to. 100,000 i ohms.

.Figure 3 illustrates a radio telephone transmitting circuit which embodies certain features of the circuit shown in Figures land 2; In this instance the vacuum tube 45 has .its. elements connected to circuits for generation of ultra high frequency which can be modulated by voice current, by talking into the microphone 9. Inductance 46 is shunted by a condenser 46a, and' thereby tuned to the desired frequency of operation. Spacedplates 41, 48 and 49" are provided,

and for frequencies of the order of from 1'65 to 225 megacycles, these plates can be discs about inch in diameter, with discs 41 and148 separated about one-quarter. of an inch by? suitable insulating material, and plates 48' and 49 separated about 0.005 to 0.010 inch by suitable insu lation such as mica. Plates 41 and 48 connect across terminals of inductance 46. Also, that sideof' the inductance to which plate 41' is connected is also connected to the plate i2- Plate 49 is connected to the grid or control element I3; The grid. 13 isalsoconnected through the small coupling. condenser 5|, with the antenna 52. This antenna maybe a conductive rod having a length corresponding to substantiallyone-quarter wave.

The terminals of the heater lib connect in series. with the radio frequency chokes 53 tothe terminals of the A battery 54. Cathode I I a is also connected to one side of the heater Hb, through the resistor and condenser 56 and 51. Disc 49 connects to one side of a radio frequency choke 58, the other end of which connects throughthe resistor 59 with the cathode Ila. The'B battery 6| has a negative terminal connected to the heater circuit, and its positive terminal is connected to the audiofrequency choke 62. Theother side of choke 62 is connected in series with an inductance;63, to the mid point of the tuned inductance46; Inductance 63 operates as a radiofrequency choke, the same as choke 53, and can be formed of 25 turns of No.24; wirewound as a helix upon a one-quarter inch form. An open ended looped wire 64, corresponding to the open ended loop 3| of Figures 1 and 2,-is closely coupledto that end'of inductance 63 which is connected I negative side of B battery (it. Cathode 14 of the pentode 12 is connected to the element 15, and also through the resistor 15 to the negative side of B battery 6|. The terminals of audio frequency choke 52v are connected to the plate 11 and the element 18 0f the pentode.

The circuit described above with reference to Figure 3 is capable of generating oscillations of the order of from to 225 'megacycles, and is relatively stable with respect to the frequency generated. The open ended loop 64 in this instance aids in attaining proper stability, and in addition makes possible additional output;

It is also desirable in connection with this oscillator to make use of a conductive plate 81 equi-distant from the terminalsof the'soeket in- The microphone 9 which the tube 45 is seated. As explained in connection with Figure 1, such a plate affords by-pass paths directly from the tube elements, and as in the case of the receiver it aids in conjunction with loop 64 in neutralizing the inductive reactance values of the tube elements. Also, in this instance use of plate 8I makes possible greatly increased energy transfer to the antenna. This is attributed to the fact that output impedance of the transmitter is decreased for the ultra high frequencies employed.

The oscillations being generated are modulated by speaking into the microphone 9, since the voice currents as amplified by the pentode I2 are impressed directly upon the inductance. Loop 64 serves to lend stability and also tends to prevent shifts in frequency, and to make for maximum output.

Figure 4 shows a further modified type of oscillator which makes use of single turn inductances of substantial diameter for determining the frequency of operation. Thus, there are two single turn loops 82 and 83 which in practice are made to the same diameter, and which are positioned in spaced parallel relationship. One terminal of the loop 82 connects to the plate I2 of vacuum tube 84, while the other terminal of this loop is connected in series with a radio frequency choke 86, the audio frequency choke 81, and the B battery 88. One terminal of the other loop 83 connects with grid I3, while the other terminal connects in series through the radio frequency choke 89, and the resistor 9| to the cathode IIa. Cath ode Ila is also connected to one side of the heater I Ib, through the resistor 92 and condenser 93. The terminals of heater IIb connect through radio frequency choke '94 to the A battery 95. One side of the A battery 95 connects with the negative side of B battery 88.

Modulating amplifier 98 is connected across the audio frequency choke 81. The antenna 91 is shown connected to a point 98 on the inductance 82, and through the variable coupling condenser 99. An open ended loop IIlI is closely coupled with radio frequency choke 86, and is directly connected to the cathode IIa. This oscillation generator will also produce frequencies of the order of from 100 to 400 megacycles, with a high degree of stability. 1

In assembling a portable radio receiver, it has been found desirable to associate certain of the parts, principally the antenna and the loops 82 and 83, with a pair of hemispheres I02 and I03, made of conductive material like copper. A possible arrangement is shown diagrammatically in Figure 5. In this instance the peripheries or open faces of the two hemispheres are spaced apart by the disc I 84 of insulating material. The center of hemisphere I02 conductively connects with the antennarod 9?. The two loops 82 and 83 are mounted upon opposite sides of the disc I84, within the hemispheres. If desired, additional parts of the receiver can be mounted within the hemispheres, with the exception of the power supply batteries, and parts of the modulating means. Such additional parts are outlined generally at I86. With hemispheres measuring about 3 inches in diameter, for range of frequencies of operation tion with a receiver capable of hypersensitive op-,

the frequency of eration, as previously described. Thus, referring to Figure 6, I have shown two loops 82 and 83, like those described with reference to Figure 4, but connected in a receiving circuit including the detectorvacuum tube I8I.- One terminal of loop 82 connects with plate I2, while the other terminal is connected in series with the inductance 21, the primary of transformer 24, and B battery 25 Inductance 21 corresponds to inductance 21-of Figure 1 and is likewise s'huntedby'condensers 28 and 38, to be resonant to the desired supersonic frequency. The open ended loop 3| is also'closely coupled to inductance 21, as in Figure 1. One terminal of the loop 83 is connected to the grid I3, and is also connected through the small coupling condenser 22 with the antenna ZI. The

other terminal of loop 83is connected through radio frequency choke I88, resistor and shunted condenser I09 and III, to the cathode I Ia. The same terminal of loop 83 is connected to the corresponding terminal of loop 82, through the condenser I I2. The secondary'of transformer 24 is shown diagrammatically connected to the audio frequency amplifier II3, 'which in turn is connected to theloud speaker II4.

The receiving circuit of Figure fi operates in substantially the same manner as the circuits of Figures 1 and 2. For a given setting of the condenser 22, the circuits will operate in accordance with conventional super-regeneration. For a reduced'value of condenser 22, the circuit passes abruptly into a state of hypersensitivity, with the virtual elimination of'background noises.

Figure 7 illustrates a type of oscillation generator circuit which makes use of two hemispheres, but which eliminates use of single turn loops corresponding to loops 82 and 83 of Figures 4 and 5. Thus, although the circuit in thisinstance is substantiallythe same as in Figure 4;

become inductances which determine the fre-' quency of operation, and these two inductances are coupled together because of the proximity between the two hemispheres.

An arrangementsomewhatsimilar to Figure? can also be used for receiving purposes, and is illustrated in Figure 8. Thenumbering of the parts in this instance corresponds generally :to Figure 6. The two hemispheres H8 and II I in this instance take the place of the loops 82 and 83 of Figure 6, and are similarly connected in the circuit. j

Figure 9 shows a. radio transmitter and receiver arrangement for two way communication. The receiving circuit is similar to that described with reference to Figure 1, or the transmitting circuit is similar to that described with reference to Figure 3. The two cathode heaters Nb of the tubes I0 and 45'are shown supplied with current from the same A battery I2I. The pentode I2 corresponds to the pentode I2 of Figure 3, but

functions as a combined modulation current amplifienand as an a'mplifier'of the received signals.

A special audio transformer I22 is coupled to the pentode I2, and is provided with two separate primary windings I23 and I 24. The secondary of transformer I22 is shown shunted'by the resistor I26',.and has its one terminal' c'onn'ected to the grid II of the pentode. The other terminal of the transformer secondary connects resistor I21 and shunt condenser I28 to the cathode I4 and pentode element 15. a

Output transformer I29 has its primary connected to plate I1 and pentode element 18, and its secondary is connected-to the voice coil of loud speaker I3I. A manual change-over switch I32 is provided which has four sets of switch contacts I, 2, 3 and 4. When the blades of the switch are all moved in one direction, namely upwardly as viewed in Figure 9, contacts I and 2 are closed, contacts 3 and 4 are opened and the system is in condition for sending. When all of the blades are moved downwardly, contacts I and 2 are opened, contacts 3 and 4 closed, and the system is in condition for receiving. Contacts 2 are connected in series with the circuit for the loud speaker I3I, so that the loud speakeris open circuited when contacts 2 are-opened. Contacts I are connected in series with one terminal of transformer primary I23, and the positive side of the B battery I33. Contacts 3 connect in series with one side of the microphone I34, and the plate TI of pentode I2. Contacts 4 connect in series between the plate of pentode I2 and choke 63 of the transmitten The other terminal of transformer primary I23 connects with the tuned inductance 21, which as previously described, determines the supersonic frequency for the receiver. The other terminal of the primary I24 is shown connected to an intermediate point of the A battery I2l.

Assuming now that switch I32 is moved to sending position, the microphone is serially connected with the transformer primary I24, so that talking into this microphone causes voice currents to be set up in the secondary of transformer I 22, and impressed upon the input of the pentode .12. Amplified voice currents in the output of pentode 12 are impressed through contacts 4 upon the circuit which includes thechoke 63 of the oscillation generator. B battery potential is also applied to the oscillator through choke 63, by virtue of the connection through the primary of output transformer I29, the positive side of 3 battery I33. When the blades of switch 132 are moved inan opposite direction, the B battery supply to the oscillator is interrupted, because of opening of contacts 4, and the microphone circuit is also opened because of opening of contacts 3. The closing of contacts I, however, connects the primary winding I23 of transformer I22 with the positive side of B battery I33, to energize the receiver, while closing of contacts 2 closes the output circuit of transformer I29, so that received signals are properly reproduced by the loud speaker.

Figure shows a circuit diagram for receiver and transmitter substantially as shown in Figure 9, but without using a change-over switch. In this instance, the transmitter and receiver must operate upon two distinct frequencies. In this instance the change-over switch I32 of Figure 9 is omitted, and the primary I24 of transformer I22 is directly connected to the microphone I34. Conductor I36 directly connects the plate of the pentode 12 to the radio frequency choke 63 of the oscillator circuit, thus directly applying the amplified audio frequency output of the pentode to the transmitter. Received signals are also amplified by the pentode I2, and applied to the loud speaker I3I. Assuming the use of two distinct frequencies, as for example 125 megacycles for the. transmitter, and 175 megacycles for the receiver, both transmitter and receiver can remain in constant operation during two way communication.

' Figure 2a illustrates a possible modification of the receiver shown in Figure 2. Tube I40, however, is a triode, and the terminals of cathode II connect through radio frequency chokes I to the A battery I42. Resistors I43, having values of the-orderof 3500 ohms each are connected in series across the cathode terminals, and the mid point of connection between the resistors is connected to loop 3|. Disc 43 at its mid point connects with plate 43 through the grid leak and grid condenser I44, I45, and the radio frequency choke I46.

Figure 3a illustrates a further possible modification of Figure 3. In this instance tube I5I is a triode with its terminals connected through radio frequency chokes I52 to the A battery 54. Resistors I53, of suitable values, such'as 1,000 ohms each, connect across the terminals of cathode II, and the mid point between the resistors is connected directly to disc 49 and loop 64. Thus, resistors I53 not only establish connection with the cathode, but in addition make it possible to dispense with resistor and condenser 56 and 51, and resistor 59 and choke 58.

I claim:

1. In an electrical vacuumtube network for ultra high frequency signal energy, a vacuum tube having cathode, plate and control elements, a tuned inductance having its terminals operatively connected to the control andplate elements, a circuit including a source of B battery potential operatively connected to the inductance and to the cathode, a second inductance in series with the last named circuit between the electrical mid point of the tuned inductance and the source of B battery potential, and an open ended looped conductor coupled withsaid last named inductance, one'end of the looped conductorbeing connected to the cathode.-

2. In an electrical vacuum tube network for ultra high frequency signal energy, a vacuum tube tuned inductance having its terminals operatively connected to the control and plate elements, a

circuit including a source of B battery potential operatively connected to the inductance and to the cathode, a second inductance in series with the last named circuit between the electrical mid point of the tuned inductance and the source of B battery potential, and an open ended looped conductor coupled with said last named inductance, one endof the looped conductor being connected to the cathode, and means providing supplemental capacitances between the elements and a common point of relatively neutral potential.

3. In a radio receiving system for ultra high frequency signal energy, a vacuum tube detector including cathode, plate, and control elements, a circuit including a tuned inductance resonant to the frequency to be received, said circuit being connected to elements of the vacuum tube, another circuit including the primary of an audio frequency transformer and a tuned inductance resonant to a supersonic frequency substantially less than the frequency of the signal energy, both said circuits being connected to the elements of the detector tube with positive feed back of oscillatory energy to effect regenerative operation and with simultaneous generationof a supersonic quenching frequency, an antenna, and means for adjusting the system to a degree of sensitivity beyond that of ordinary superregenerative operation or true negative resistance, said means comprising a variable condenser serving to couple the antenna to said circuits.

, 4. In a radio receiving system for ultra high frequency, signal energy, a vacuum detector tube including cathode, plate and control elements, a circuit tuned to the frequency of thesignal energy, and operatively connected across the plate and control elements of the vacuum tube, said circuit including a tuned inductance, a source of B battery potential having its negative terminal connected to the cathode, an audio output transformer having its primary connected in series with the positive terminal of the B battery potential, another inductance resonant to a supersonic frequency, one terminal of said inductance being connected to the primary of the audio frequency transformer and the other terminal being connected to the electrical mid point of the first named inductance, an antenna, and a reactance serving to couple the antenna to the first named circuit, said reactance having a value less than that required for conventional super-regenerative operation of the system and such that the system is hypersensitive to reception of signal energy.

5. In a radio receiving system for ultra high frequency signal energy, a vacuum detector tube including cathode, plate, and control elements,

a tuned inductance resonant to the signal energy and having its terminals operatively connected across the plate and control elements, a source .of .B battery potential having its negative termiwith the primary of the audio frequency transformer and the electrical mid-point of the firstnamed inductance, an open-ended looped conductor coupled with the last-named inductance, one end of said conductor being connected to the cathode, an antenna, and a reactance serving to couple the antenna to the circuit formed by the first-named tuned inductance, said reactance being at a value less than that required for operation of the system according to conventional super-regeneration and such that the system is operated at hyper-sensitivity.

6. In a radio receiving system for ultra high frequency signal energy, a vacuum tube detector including cathode, plate and anode elements, a circuit connected across the plate and the control elements, said circuit including an inductance tuned to the frequency of the signal energy and also a grid leak and grid condenser, a source of B battery potential having its negative terminal connected to the cathode, an audio frequency transformer having its primary serially connected with the positive side of the source of B battery potential, a second tuned inductance serially connected between the electrical midpoint of the first-named tuned inductance and the primary of the audio frequency transformer, a pair of condensers in series with each other and connected across the terminals of said lastnamed inductance, one of said condensers having a relatively high capacitance and serving as a by-pass condenser, and the other having a relatively small capacitance and serving to tune the inductance to a supersonic frequency substantially less than the frequency of the signal ener y, a connection between the cathode and the point of inter connection between said condensers, an. open-ended looped conductor coupled to the second-named inductance, one end of said looped conductor being connected to the cathode, an antenna, and a reactance serving tocouple the antenna to the first-named circuit, said reactance having a value less than that required to operate the system in accordance with conventional super-regeneration and such that the sys tem is hypersensitive.

7. In a radio system for ultra high frequency signal energy, a pair of looped conductors disposed in spaced parallel planes, and electrically coupled together, a vacuum tube including cathode, grid and plate elements, a source of B battery potential having its negative terminal connected to the cathode, aninductance connected in series with one terminal of one of the looped conductors and thepositive side of the source of B battery potential, the other end of said one looped conductor being connected to the plate element, a connection between one terminal of the other looped conductor and the plate, a radio frequency choke connected between the cathode and the other terminal of the other looped conductor, an open-ended looped conductor coupled to the firstnamed inductance, one end of said last-named conductor being connected to the cathode.

8. In a radio system for ultra high frequency signal energy, a vacuumv tube. having cathode, plate and grid elements, input and. output circuits connected to the elements of the vacuum tube, a pair of hemispheres formed of conductive material, the peripheries of said hemispheres being in adjacent spaced relationship, and an inductance tuned to the frequency of the signal energy included in said circuits and disposed within said hemispheres in a plane adjacent the medial plane between theihemispheres so that a "fly-wheel action results with extremely small amount of, impedance. I

9. In a radio system for ultra .high frequency signal energy, a vacuum tube including cathode, plate and control elements, oscillatory circuits connected to said elements, said circuits including an inductance tuned to the frequency of the signal energy, apair of hemispheres formed of conductive material, the peripheries of said hemispheres being inadjacent spaced parallel relationship, said inductance being in the form of a fiat loop disposed inaplane adjacent the medial plane between the hemispheres, reactive means serving to couple said looped conductor to one hemisphere, and an antenna conductively connected to the mid point of said one hemisphere. 10. In a radio system for ultra high frequency signal energy, a pair of hemispheres formed of conductive material, the bases of said, hemispheres being in juxtaposition and in spaced parallel relationship, a vacuum tube having cathode, plate and control elements, an input circuit connected across the control and cathode elements, said input circuit having two spaced points of connection to the periphery of one of the hemispheres, whereby said hemisphere is made an inductive element of the input circuit, said output circuit also having two spaced points of connection to the periphery of the other hemisphere whereby the other hemisphere is likewise made an inductive element of the. output circuit, and an antenna conductively connected to the center of said last named hemisphere. I

ELMER L. BROWN,

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