US1720150A - Radio receiving system - Google Patents

Description

July 9, 1929.

R. ROSS 1,720,150

RADIO RECEIVING SYSTEM Filed July 22 1.926

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Patented July 9, 1929.

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: P AWE'N'T =19 F REUBEN ROSS, .0F- BROOKLYN NEW' 'YiORK.

. RADIO ;RECEIVING SYSTEM.

Application filed July- 22, 1926. Serial No. 124,153.

This invention relates to radio receiving systems, and more particularly to systems having both radio and au'dio stages of amplification and employing electron discharge tubes as the amplifying meansin such stages.

.The object of'the invention generally is ,to providean improved device oi the character described, which is eficctive, economical and readily manufactured.

.More particularly an object is to provlde a radio receiving system of the modern type having both radio and audio stages of amplification which gives substantially distort-ionless reception. v

Other obj ects of the invention will in part .be obvious and'avill in part appear hereinafter. H l ,1

The inventionaccordingly comprises the [features ofconstruction, combinationsot clement-s, and arrangement'of parts, which will be exemplified in the constructions hereinafter set 'ior'thand the scopeof the application-ref which will bc indicated in the claims. .Forafuller understanding of the nature ,and objects of the inventionrci'er'encc should be had to, thefollowing detailed description taken in connection with the accompanying drawings, in which:

Figure 1 shows, diagramniat-ically, a radio receiving system constructed inaccordance with the present invention, and utilizing standard parts; and

2'sh'ows,.in similar fashion, aradro system like that in'Fig. 1 but arranged-to utilize tubes and audio transformers which ,are especially adapted to the prcsent, inven- Referringgnowto the drawi11g,,and first to Fig..l,.a; receiting system is shown having .an.aerial' 10 connected, through winding 11 ,to ,ground,12.iorpicking up theenergy of the radio signal in the usual manner. The energy thus pickedup is here shown ainplifiedby means of one radio stage, a detecting stage and two stages of audlo; each stage preferably employs an electron d scharge tube as the amplifying means, or detecting .means, .as the case may be.

.iAll electron discharge tube otthe twolor three-element variety, as is well known,.,has unilateral conductivity, .so. that .when {connected .in a circuit traversed by alternat- ,ing.currents, such a .tubeopcrates likea rectifier to. cut off .onerhalf of the aiternatin .carr enj: .rwave. jiizidio, systems 2 rice mmv ,hwentwn. hatejheenethstantie y .iifiwexatt ly actuated by half-wave pulses transmitted as a result of amplification by means of devices which have rectified current characteristics. The utilization of only the half of the. alternating current wave is not only the source of much inefiiciency in the recep- 11011 ot radio SIgIlZLlS'IH modern receiving systems, but also has been ascertained to be the source of .much of the distort-ion in the reproduction of signals.

In the practice of the present invention this source of distortion is substantially eliminated. This is accmnplished by an arrangement of. tubes adapted to transmit the full wave, although through. a divided cirhave a common tap 1 1 leading to one/filament electrode 15 ot a pair of parallel connected tl'n'ec-element tubes 'lGand' 16. These tubes have their grid electrodes 17- and 17 respectively connected to the other ends of windings'ld and 13. The plate electrodes 18 and 18 are also connected in parallel to the end terminals of a winding 20 of a radio transformer which is also in two parts, the winding parts having a common tap or midpoint conductor 19 adapted to be connected to a ii-battery.source of relatively high voltage DC. The source as here indicated-is a pair of bus-bars ;2122 properly energized. Conductor 19 is shown ascennected to bus-bar 21 for this purpose. .There is also shown as associated with these busbars a third-bus-bar, designated 23; these three comprise a means serving .as the C0111- inon source of high and low voltage electric energy for the system here illustrated. :The bus-bars 2223, which are connected to supply the current for heatingall the filaments,

may, in like manner, he referred to as an Asbattery source.

Thewindings 13 and 13,ar'e connected in The detecting stage is inductively coupled to the, first stage ,by means of the. iadlotransthe seeondaryflaofwhich is di vi so int ggaixteieiiciler teflie-gefimaig'ymml til connected respectively to the grid-electrodes 2'7 and 27' of the tubes 26 and 26, which tubes are here depicted as detectors. Resistance elements 28 and 28 are shown as con nected across the grids and filaments of these tubes, but any convenient means adapted to maintain the desired potential across these,

may be reversed and impressed on the audio stage; transformer 30, as shown, has a divided or split secondary 32; the end terminals of winding 32 are connected 'to the grid electrodes 3'7 and 37' of the tubes 36 and 36', while the mid-terminal 35 of this secondary is connected to one side of tlie filament busbars. i

The plate electrodes of tubes 36 andBG' are connected through parallel circuits with what is in effect a second audio transformer 10 having split windings by which the'secend stage of audio amplification is produced; this second stage of audio amplification also ha tubes l6 and lti' connected in'parallel as in the prior stages. The plate electrodes of these last tubes are again connected to the windings of what is in effect an audio transformer having split windings, a second- Y ary of which is connected for energizing a translating device ()0 such as telephones or a loud speaker.

By the arrangement shown, it is seen that the half wave transmitted by one tube in each stage is balanced by that transmitted by the other tube. a stage ceases to function and transmit signal energy; consequei'itly in the audio stages the magnetization of the audio transformers is substantially always balanced. In the: transformers at 30, 4.0 and 50 this balanced effect insures that the iron of the magnetic core is at no time free from magnetization. This effect is enhanced in the transformer at 30 by the use of one having a single primary and two secondaries on theone core. The

effect of one transformer having split windings however, may be had by the use of two transformers connected as shown at 40. In this arrangement it is preferable to have the cores substantially abutting, so that there is natural magnetic linkage; a similar arrangement is shown at 50.

Since the cores here in the audio stages are substantially always magnetized, the harmonics due to the intermittent magnetization of cores by the current heretofore unilaterally transmitted from a single series of tubes is absent, together with diminution by hysteretic'losses; The reproduction of the signal received in the translating device 60 has in consequence great strength and is substantially free from distortion.

There is no instant when In order that the energy traversing the parallel sides of the respective stages in the arrangement shown in Fig. 1 may give a fully balanced effect, the currents in the two sides should be as nearly equal as practical and'in phase. Consequently care is taken that the inductance in the two sides of the circuits in each stage has as nearly equal values as practical. Care should also be taken to avoid having these circuits at any point intercepted by leak: ge flux; shielding may therefore be resorted to with advantage. An arrangement is shown in Fig. 2 in which special parts are employed. Here the aerial 10 is connected throughwinding 11 to ground 12. The end terminals ofthe divided secondary, coupled to winding 11, however are here not connected to the grid electrodes or parallel connected three-element tubes, but instead are connectml in parallel respectively to the two grid- electrodes 77 and 77 of a single special five-element tube 76.

I The five-element tube here illustrated has one filament, two grid-electrodes and two plate-electrodes. The latter are shown at 78 and 78 and haye parallel connections leading to the opposite terminals of a divided primary of a radio transformer at 80, which couples the first radio stage to the detecting stage; the latter having a fiveelement detecting tube 86 connected similar to that at'TG. The plate electrodes of. tube 86 are connected'in parallel to an end terminal of an audio transformer 90 having a divided primary and secondary, the prin'iary sections bcing connectcd in parallel and arranged to increase the magnetizing effect. The balanced effect in this case is enhanced by providin g one transformer having a C6111 mon iron core in the two sides of the circuit. In this way the magnetization of the core is substantially always .present and is substancore.

Two stages of audio using the five-element tubes shown at 96 and 1.06, are coupled successively thereto. Due however to the balanced transmission of the signal in the audio stages here employed, three or more' stages of audio may be employed equally well. A translating device is coupled to the last stage of audio through the audio transformer 110 which is also shown as having a common iron core for the parallel sides of the circuit which lead from the plateelectrodes of the last audio stage. A common source of filament heating current for the special'clectron discharge tubes is here shown at 83, but as it is frequently preferable in multi-stage receiving systems to use various voltages in the plate circuits, the stages are here shown as provided with individual sources of current-energy for plate circuits. It will beu'nderstoocl however that .tially uniformly distributed throughout the any convenient arrangement for supplying selected plate voltages from one or more sources is within the purview of the present invention.

The arrangement shown in Fig. 2 dill'ers essentially from that shown in Fig. 1 only in the use of the special five-element tubes and in the use of the specially wound audio transformers which latter have common cores for the divided windings. By the arrangements shown in F 2 the present invention is practiced in a highly eilicient form but it is seen that the use of transmitted balanced half waves united in the audio stages and in the translating device to give a full wave eil'ect characterize the arrangemerits of each.

Since certain changes may be made in. the above construction and different embodtments of the invention could be made with out departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accon1- panying drawing shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a radio receiving system, the combh nation with receiving means, of anmlifying stages connected in cascade therewith having amplifying means with rectifying characteristics connected therein and arranged to provide parallel paths for unilaterally eonducting each of the half-wave trains of the full-wave signal, an intermediate stage thereof being arranged as a detecting stage, means for reversing one of said half-wave trains associated with said detecting stage, said reversing means being arranged for transmitting the reversed wave train additively with the 'unreversed train in parallel paths through the succeeding cascade stages, and a translating device connected to the last stage whereby the same is energized continuously by said additive parallel wave trains.

2. In a radio receiving system, the combination with receiving means, of amplifying stages connected in cascade therewith having electron discharge tubes connected therein and arranged to provide parallel paths for unilaterally conducting eachof the halfwave trains of the full-wave signal, an intermediate stage thereof being arranged as a detecting stage, means for reversing one of said half-wave trains associated with said detecting stage, said reversing means being arranged for transmitting the reversed wave train additively with the unreversed train in parallel paths throiiigh the succeeding c1 scade stages, and a translating device connected to the last stage whereby the same is energized eontinimusly by said additive parallel wave trains.

In a radio receiving system, the combination with signal receiving means, of amplifying stages connecti-al in cascade therewith, including a detecting stage, and a subsequent audio stage, each of said stages having amplifying means with a rectifying characteristic connected therein and arranged to provide parallel paths for unilaterally conducting each of the half-wave trains of the full-wave signal, a transformer associated with said detecting stage and arranged to comprise the coupling between said detecting stage and the subsequent audio stage, said transformer having a winding for reversing one of the half-wave trains from said detecting stage, said audio stage having inductive cormling means provided with windings divided between said parallel paths and with effective common magnetic coimling means, and a translating device inductively coupled to said cascaded stages whereby the same is continuously energized with full-wave energy.

i. In a radio receiving system, the combination with signal receiving means, of ampli- 'lying stages connected in cascade therewith including a detecting stage and a subsequent audio stage, each of said stages having threeelectrode-eleetron discharge tubes connected therein and arranged to provide parallel paths for unilaterally conducting each of the half-wave trains of the full-wave signal, a transformer associated with said. detecting stage and arranged to comprise the coupling between said detecting stage and the subsequent audio stage, said t. 'ansformer having a winding for reversing one of the halfwave trains from said detecting stage, said audio stage having inductive coupling means provided with windings divided between said parallel paths and with effective common magnetic coupling means, and a translating device inductively coupled to said cascaded stages whereby the same is continuously energized with full-wave energy.

In testimony whereof I aflix my signature.

tEUBEN ROSS.

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