US1751081A - Radio apparatus - Google Patents

Description

msmsl Mm'ch 18, WW. A. GOLLOS RADIO APPARATUS Filed May 13, 1929 5 Sheets sheet l [771/971 for Una/fol 020 Mam l8, EQBQ, A. GLLO$ RADIO APPARATUS Filed May 13, 1929 5 Sheets-Sheet A. GGLLG RADIO APPARATUS Mach E8, 1%

Filed May 15, 1929 5 Sheets-Sheet A L V0 March 18, 1930.

A. GOLLOS 1,751,081

RADIO APPARATUS Filed MaylS, 1929 5 Sheets-Sheet 5 a 7 Inventor i ESE/Y7, Qnatol Galina.

EM I I I I, a

Patented Mar. 18, 1930 UNITED STATES ANATOL GOIJLOS, OF CHICAGO, ILLINOIS RADIO. APPARATUS Application filed May 13,

This invention relates to radio apparatus and relates particularly to such apparatus of the multi-phase type.

Principal objectsof the invention are to provide a new and novel radio frequency amplifying circuit whereby more energy can be transferred from an electron valve to a succeeding electron valve than by present known circuits of which I have any knowledge, without in any way producing phase distortion or causing a loss of selectivity in the circuit; to provide a band pass system within a predetermined band of frequencies whereby increased and undistorted potential will be impressed upon the input circuit of a succeeding electron valve; and to provide good selec ivity and improved tone qualities.

It is commonly known that the voltage appearing in the plate circuit of an amplifier tube is: M Eg (A. 0.), where M=amplification constant, and Eg=applied grid voltage (A. C.). Therefore it is apparent that if. a higher grid voltage (Eg) is applied, a correspondingly higher plate voltage (A. C.) will appear in the plate circuit, always keeping in mind that the maximum applied potential shall not cause the grid of the succeeding electronic device to swing positive and thus produce distortion. In accordance with my invention, I have devised means for thus applying such higher grid voltages to electronic devices by purely resonant coupling schemes in association with suitable phase shifting devices.

In accordance with the present invention, I attain the foregoing object in the following manner, as fully shown in the accompanying drawings, in which- Figure 1 is a diagrammatic view showing a preferred system of circuitsand controls embodying my invention and improvements as applied to radio receiving apparatus;

Figures 2 and 3 are views substantially similar to Figure 1, showing modified systerns of circuits and controls adapted for the 1929. Serial No. 362,822.

practice of my invention as applied to radio receiving apparatus;

Figure 4 is a view substantially similar to Figure 1, showing apparatus having additional phase shifting devices;

Figure 5 is a view showing circuits and controls of radio receiving apparatus of the general type shown in Figs. 2 and 3, having the characteristics of the arrangement shown in Figure 4:;

Figure 6 is a vector diagram;

Figure 7 is a comparative diagrammatic view of resonance curves illustrative of present practice and those resulting from the practice of my invention;

Figure 8 is a widened resonance curve tending to show graphically the band pass curves produced by my invention; and

Figures 9 to 14 are vector diagrams.

Describing the operation of the apparatus with particular reference to Fig. 1, potential is impressed upon the input circuit of the first electron valve VT from .any source, not shown. This potential may be any form of modulated or unmodulated alternating voltage.

Due to the factor (M Eg) as described above, an A. C. voltage appears in the output circuit of this electronic device and is impressed across the primaries L L and, by ordinary electro-magnetic induction, voltages appear across the circuits L Ca and L C at frequencies at which these circuits are resonant. These voltages differ in phase displacement by an optimum phase difference, which in the diagram (Fig. 1) is 180. This action is similar to that which takes place in the windings of the commonly known deltaconnected transformer used in poly-phase transmission circuits. These voltages which appear across L Ca and L C may be symbolized as E and E respectively.

A clear understanding of the method whereby the phase difference between the two electrical elements E, and E (which ap- 90 since L and L are spaced apart, the voltage component E will appear across L Ca with an appreciable phase lead over that of the voltage component E appearing across .L C this phase lead depending on or being varied by the coupling between L L These primaries are preferably spaced somewhat apart so as to avoid coupling between them which would cause one field to oppose the other and cause loss of power. The phase lead E over E is represented vectorially in Figs. 9 and 10, as the maxima EM and EM The circuit L L X0, Fig. 2, is essentially the same as L L X0, Fig. 1, but is shown symbolically.

The nature of the invention will be clearly understood by referring to Fig. 1, in which the output from the thermionic amplifier or repeating tube VT is led to the mutual reversed coils L L by means of wire 21, the two coils being opposingly coupled by wire 22. Coupled to L inductively is a coil L which may be tuned to resonant frequency F by the variable condenser Ca, which is shunted across L one side going to the grid of the following repeater tube VT by wire 23, the other side of this mutual combination L Ca going to resistance R which is used to produce a negative bias on the grid of the followingrepeater tube to prevent the grid bias from swinging positive and thus producing distortion. The coil L is coupled inductively to the coil L which is tuned to resonance at frequency F by the condenser G a common point of the two condensers Ca C being mutually grounded so as to prevent the effect of body capacity. A common point of the circuit C L is connected to a series condenser X0 by wire 25, the other side of X0 going to mutually coupled coil L, by means of wire 26, and a wire 27 connects the other end of L to the reversed coil L which is coupled inductively to L and a wire 28 connects the coil L to the grid of the following repeater tube VT.

The coupling between L and; L is Very small due to the fact that L L are opposing. The energy transfer between these two inductances is, therefore, negligible.

Fig. 3 is essentially the same circuit as Fig. 2, but is shown symbolically so asto clear'the point of band pass action in which it is clear that circuits L Ca and L C are coupled by the auxiliary circuit L 'L X0, and by means of variation in the reactance of X0, this circuit causes a continual tightening of coupling agrees with its theoretical values.

as frequency decreases, L L in Fig. 3 being coils L L in Fig. 1, but shown symbolically.

Considering the associated circuits L L X0 and symbolizing the voltages that have appeared across L Ca as Em in Fig. 9 and across L- C as Em these are shown vectorially difi'ering in phase by angle a.

Now, by magnetic induction due to the physical relationship of the two coils L and L a voltage component appears across L 180 out of phase with EM This is shown in Fig. 9 as EM Therefore, since the circuit L L X0 is near its resonance points, its reactance approaches zero by the law:

XL=21rfL Xc= zTlFc (X0 is negative) at resonance XL= Xc. XL+X0= 0 at resonance Z /R and R being negligible,

Z=0 at resonance (approximately),

where XL=inductive reactance at frequency F and Xc=capacitive reactance at frequency F,

R=D. C. resistance and Z impedance at frequen cy F.

Since the reactance of circuit L L X0 is near zero, and its current maximum a voltage Eon, (Fig. 9), appears across inductance L But, due to the reversed condition of this coil, Em. is 180 out of phase with Em (Fig. 9). Again due to mutual inductancebetween L and L, a voltagecomponent appears across L this voltage being designated Em- Fig. 9, being 180 out of phase with Em in phase with Em and out of phase with Em by angle a. Now, by means of the ordinary vector method or trigonometrical method, we combine E722 and Em and produce Em the increased voltage applied to the grid of the following electronic device. Thus increased voltage has been actually measured and fully Figure 10 shows the method of obtaining this voltage Em vectorially and Fig. 6 graphically. An analysis of the method of combination follows.

Referring to Fig. 6,

Let e =voltage across L 0a, Fig. 1;

Let e =voltage across 11 0a, Fig. 1, due to voltage Em, as described above;

Then eo=the desired voltage increase applied to tube grid.

Equation of sine Wave=y=a sin biz: substituting e for y Em for a 27r I I tfor bx 21 a: .e-Em S111 t.or since T frequency e=Em sin ZarfT Let 'w 21rf .'.e=Em sin wT Now let e =Em sin 101 where w=21rf e =Em sin (wT-a) then by addition, using trigonometrical law for sum of two lines times constants,

varying the voltage applied to the following grid circuit between 6 or 6 and 6 6 This is clearly shown in vector diagrams in Figures 11, 12, 13, in which angle a assumes different values and co becomes larger as (1 approaches zero.

I have thus without any loss or difficulty produced an increased applied Eg to the input circuit of a following electronic value.

As explained above, the means by which increased amplification is obtained is not dee 0 (Em +Em cos a) (Em-2 Sin sin (wT- tan Concluding therefore from this equation, it readily can be seen that e0 is at all times larger than either e or 6- with a maximum of e +e and a minimum of either (2 or 6 being the above mentioned quantity Em applied to theinput circuits of the following electronic device.

The same result may be shown vectorially in Figure 10.

it is, of course, understood that Em in Fig. l0=maximum value of co in Fig. 6, one being the vectorial quantity and the other being the graphical quantity.

It is to be noted in Figure 6 that as angle a becomes larger, 60 becomes smaller with a minimum of either 6 or 6 and when 00 is at ,a maximum, a=0 and e0=e +e It is well to note here that in the accompanying circuit, Fig. 1, optimum conditions have beenused; that is, 6 and e are 180 out of phase and angle a=0. Therefore E0 applied to following grid is maximum and e0=e +e The angle a may be varied by varying the coupling between L, and L thus Em; sin a Em Em cos a multi-phase appliance, the phases used not being limited in any way.

This is clearly apparent from Fig. 4, in which L L are similar to L L in Fig. 1, L Ca L C being similar to L Ca L 0 Fig. 1 and the auxiliary circuit L X0 L being equivalent to L X0 L Fig. 1, the aforementioned so far being the two-phase system. We now add inductance L tuned to resonance frequency F by condenser C "This auxiliary circuit represents the third branch in the star connected system, while the auxiliary branch X0 L and L represent an auxiliary band pass s stem so as to produce similar conditions t roughout the band pass circuit, Fig. 5 being essentially the same as Fig. 4, but laid out to represent the common star connected electrical system common to polyphase transmission.

Next referring to Fig. 7, it would be best to describe a problem which has been holding the minds of the radio engineering field. This is the problem of gaining selectivity without producing distortion by the effect commonly known as side-band cutting. It is well known in the art that it is essential to high quality reception that the resonance curve of the tuning apparatus in radio receivers be at least 10 kilocycles wide, the reason for this being that broadcast transm ssion, as practiced today, is done by modulating the radio frequency carrier wave, which is known as the fundamental, with frequencies varying onboth sides of this fundamental from frequencies as low as 60 cycles for the percussion type of instrument to 5000 cycles for the higher pitched reed instruments. This produces a maximum envelope of approximatel 10 kilocycles. It would be a tremendous a vance in the art if it were possible to produce a resonant curve 7 which would be 10 kilocycles wide from base resonance, due to a narrowing of the resonance characteristic and a subsequent cut ting, of so-called side bands. So far, any endeavor to produce a widening of this common resonance characteristic has produced not only a loss of amplification but also a loss of selectivity, due to the base of the resonant characteristic spreading out. It has to date been deemed an improbability, if not an impossibility, that the perfect resonant curve C, Fig. 7, be even approached.

In my circuit, by a unique method, I have closely approximated the perfect resonance curve, without any attendant loss of either amplification, selectivity or quality. This is done in this wise :Note in Fig. 1 that there are two associated resonant circuits, L Ca and L C Both-of these circuits have sharp resonant characteristics, such as shown in curve a, Fig. 7. However, when these circuits are resonant at the same frequency, these two curves coincide. But if'it were possible to produce a slight difference between the peaks of these resonance characteristics, we can produce, by a combination of these two, an approximation of the perfect resonance curve C, Fig. 7. This is shown graphically as curve I), Fig. 7. By varying the difference of these two peaks, we can make the width of the charactristic any predetermined quantity.

The method in which variation between the two resonance peaks is accomplished is described in the following:

Note associated circuits L L X0 in which L is coupled inductively to L and L is coupled inductively to L If we let M represent the mutual inductance between L and L it becomes obvious that, as M increases, the coupling between L and L becomes greater with an increase in energy transfer, but since L and L, are fixed, it is advisable to vary M by other means than those mechanical. Note that L is also coupled to L inductively. Let us here represent the mutual inductance be tween these two coils by the letter M It is evident then that resonance circuits -L Ca and L C are coupled by means of the auxiliary circuit L L X0 through mutual in-' ductances M and M Since L L X0 represent an auxiliary circuit of the series resonant type, the amount of energy transferable between L Ca and L 0, through auxiliary circuit L L X0 is directly dependent upon -X0. It is commonly known in the art that, if two resonance circuits are coupled together inductively, both resonant at the same frequency, they will for one value of coupling produce a single resonant curve such as in Fig. 7, curve a; but as we increase thecoupling between these two circuits, the two resonance curves begin to recede from each other and roduce a double peaked curve such as in ig. 7, curve I). In accordance with my invention, this tightening of coupling between the two resonant circuits L Ca and L 0 is produced by means of increasing the energy transfer between the aforementioned resonant circuits in this manner.

Note associated circuit L X0 L This circuit acts as a link circuit which serves to couple L Ca and L 0 by means of mutual inductance between L and L Let us designate this M The mutual inductance between L, and L is designated M However, since the reactance of the X0 condenser is Rs f it is readily seen that its reactance is inversely proportional to freqency.

The energy transfer between L and L is proportional to M The energy transfer between L, and L is proportional to M The energy transfer between L, and L is inversely proportional to R0 and proportional to frequency since R0 is inversely proportional tofrequency and the voltage drop across X0 increases as frequency decreases.

It is plain now then, that as frequency decreases there will be less energy transfer between L and L due to the greater reactance drop across X0 with a corresponding decrease in coupling between L Ca and L C and the production of a narrower band pass curve. Y

I claim:

1. In a system of the character described, opposed primary inductances adapted to be energized from a common source of radio frequency, tuned secondary inductances each coupled with one of said primary inductances, a vacuum tube having a grid connected to one of said secondary inductances and phase correcting means associated with another secondary inductance for impressing upon the grid a second voltage substantially in phase with the voltage in the secondary inductance connected to the grid.

2. In a system of the character described, a source of radio frequency current, and

.means for establishing a relatively high potential from said current, comprising a primary winding traversed by said current, said winding having opposed portions, a resonant circuit coupled to each of said portions, said resonant circuits having a common ground and an auxiliary circuit coupled with one of said resonant circuits to receive energy therefrom and coupled with the other of said resonant circuits to induce potential therein complementary to the potential induced therein by the primary winding.

3. In a system of the character described, a. source of high frequency alternating current, a vacuum tube having a grid, and means connected to said grid for transferring energy from said source to said grid, comprising a plurality of circuits tuned to resonance at said frequency, means connected with said source for setting up potentials in said circuits that are substantiallyreversed in phase, and an auxiliary circuit associated with said tuned circuits receiving energy from one of said circuits and by means of the energy received inducing in the other of said circuits an added potential of the same frequency.

4. In a system of the character described, a source of high frequency-alternating current, a vacuum tube having a grid, and means connected to said grid for transferring energy from said source to said grid, comprising a plurality of circuits tuned to resonance at said frequency, means connected with said source for setting up potentials in said circuits that are substantially reversed in phase, and an auxiliary circuit associated with said tuned circuits receiving energy from one of said circuits and by means of the energy received inducing in the other of said circuits an added potential of the same frequency and in phase therewith.

5. In a systemof the character described, a source of high frequency alternatingcurrent, a vacuum tube having a grid, and means connected to said grid for transferring en-' ergy from said source to said grid, comprising a plurality of circuits tuned to resonance at said frequency, means connected with said source for setting up potentials in said circuits that are substantially reversed in phase, and an auxiliary circuit associated with said tuned circuits receiving energy from one of said circuits and by means of the energy received inducing in the other of said circuits an added potential of the same frequency, said second named means including a pair of primary windings connected in series with said sourceiand having opposed fields.

6. In a system of the character described, a source of high frequency alternating current, a vacuum tube having a grid, and means connected to,said grid for transferring energy from said source to said grid, comprising a plurality of circuits tuned to resonance at said frequency, means connected with said source for setting up potentials in said circuits that are substantially reversed in phase, and an auxiliary circuit associated with said tuned circuits receiving energy from one of said circuits and by means of the energy re- 'ccived inducing in the other of said circuits an added potential of the same frequency and in phase therewith, sa1d auxiliary circuit 111- eluding capacitative means the reactance of 'which decreases proportionately to the 1ncrease in frequency of the current therein.

7. In a system of the character described,

a source of single phase high frequency energy, a vacuum tube repeater having a grid, means for changing said single phase energy to multiphase energy, and recombining the multiphase energy into single phase energy of higher potential, and connections for impressing said energy upon said grid.

8. In a-system of the character described, a source of single phase high frequency energy, a vacuum tube repeater having a grid, means for changing said single phase energy to multiphase energy, and recombining the multiphase energy into single phase energy of higher potential, and connections for impressing said energy upon said grid, said means including a plurality of circuits resonant at the same frequency.

9. In a system of the character described, a source of single phase high frequency energ a vacuum tube repeater having afor impressing said energy upon said grid,

said means including primary coils connected to set up opposed fields and connected in series.

10. In a system of the character described, a source of single phase high frequency energy, a vacuum tube repeater having a grid, means for changing said single phase energy to multiphase energy, and recombining the multiphase energy into single phase energy of higher potential, and connections for impressing said energy upon said grid, said means including a pair of resonant circuits having a common connection and means for transferring energy to said circuits in opposed phase relation.

11. In a system of the character described, a source of single phase high frequency energy, a vacuum tube repeater-having a grid, means for changing said single phase energy to multiphase energy, and recombining the multiphase energy into single phase energy of higher potential, and connections for impressing said energy upon said grids said means including primary coils connected to set up opposed fields and connected in series, secondary coils inductively coupled with said primary coils, and 'means for reversing the phase of. the energy transmitted to one of said secondary coils.

12. A method of radio frequency amplification which consists in causing the plate current of an electron valve to induce in intermediary coils between said valve and a succeeding valve voltages of different phase, inducing voltage in an auxiliary circuit from one of said intermediary coils, inducing voltage in the other of said intermediary coils 13. The method of transferring energy from one electron valve to a succeeding elec tron valve which consists in transferring energy from the output of the first valve to a plurality of resonant circuits and at the same time changing the phase relation of a portion of said energy to the remainder thereof transferring energy from one of said circuits to an auxiliary circuit and shifting the phase of the energy and thereafter transferring energy from said auxiliary circuit to the other of said resonant circuits and from there to the succeeding Valve. I p

14. In a system of the character described, an electron valve having an output circuit, a succeeding valve, resonant circuits coupled with said output circuits to receive multiphase energy therefrom, a resonant auxiliary circuit coupled with said circuits to recombine the multiphaseenergy into single phase energy, said auxiliary circuit having means for maintaining its coupling with the other circuits such as to give for a definite frequency, a sharp double peaked resonant curve.

15. In a system of the character described,

an electron valve haying an'output circuit,

a succeeding valve, resonant circuits coupled with said output circuits to receive multiphase energy therefrom, a resonant auxiliary circuit coupled with said circuits to recombine the multiphase energy into single phase energy, said auxiliary circuit having means for maintaining its coupling with'the other circuits such as to give for a definite frequency, a sharp double peaked resonant curve, said last named means including a capacity the reactance of which decreases in proportion to the increase in frequency.

In witness that I claim the foregoing as my invention, I aflix my signature this 10th day of May, 1929. a I

ANATOL GOLLOS.

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