US1999137A - Radio apparatus - Google Patents

Description

Apr-il' 23,v 1935.v

E. T. FLEwELLlNG 1,999,137

RADIO APPARATUS v u Filed Aug. l0, 1926 2 Sheets-Sheet l E1 .'8,

a@ QAAM April 23, 1935.y

E. T. FLEWELLING RADIO APPARATUS 2 sheets-sheet 2 gnvanlfoc Patented Appr. 23, 1935 PATENT OFFICE RADIO APPARATUS Edmund T. Fiewelling, Dayton, Ohio, assignor to Frank L.A Walker, Dayton, Ohio p Application samt 1o, 1926, serial No. 128,492-

22 Claims.

My invention relates to electrical distribution and more particularly to the interconnection of the various instruments and parts pertaining to a radio receiving or transmitting apparatus, although not limited to such application but also applicable to other group connection of electrical devices.

In the present invention there is contemplated the standardization of electrical assembly, particularly that of radio apparatus. lby eliminating the usually complicated system of cross wiring,

providing for the automatic by-passing of high frequency currents, the elimination of objectionable feed back effects and facilitating the speed and rapidity of assembly and construction of such apparatus.

In its preferred embodiment the invention comprises a combined distributor and condenser strip consisting of a plurality of separate electrical conductors arranged in parallel spaced relation, and

preferably embedded in a'body of dielectric orl insulating material, by which the multi-conductors will be maintained in a fixed relation in a unitary group assembly but disconnected one from another. The several conductors are provided at spaced intervals with outlet connections or attachment lugs for connection with various electrical instruments or devices. These electrical taps or outlets of the several conductors comprising the group assembly, are arranged in a predetermined sequence or grouped relation so that at any selected point throughout the length of the multiple conductor strip there will be conveniently and closely located a tap or outlet to each of the component conductors. The multiconductors are preferably thin at strips of sheet metal although. they may be given other forms to facilitate manufacture, economize production,

and to conform to various conditions of usage. In the present method of manufacture, these metallic conductor strips are separated one from another by interposed strips of fabric impregnated with phenolic condensation material or othermaterial possessing insulating and dielectric properties.l The assembly is then permanently united, preferably though not necessary, under the influence of heat and pressure to form a unitary strip or body in which the conductor strips are fixedly embedded in parallel spaced relation with their spaced taps projecting beyond the enclosing body.

The convenience of this multi-conductor strip for distribution of electrical current and-,group interconnection of a number of instruments or devices is, however, more or less subordinate to the intercapacity electrical effect aorded by the superposed spaced conductor strips which form a xed by-pass condenser for all alternating currents whether radio or audio frequency oralternating filament current, at any point in the 5 receiver or transmitter. The impedance and effective capacity of the multi-conductor unitary assembly may be accurately measured. Such effective impedance and capacity then becomes a known factor in the calculations incident to efficient designing of radio and other electrical apparatus. The accurate measurement of these capacity and impedance factors of the usual radio vset wiring has heretofore been impossible.

One of the objects of the invention is to eliminate the usual unsystematic wiring and to reduce to minimum both in number and lengths all connection and leads carrying electrical current of the various characteristics and frequencies found in radio receiving or transmitting apparatus. 20 There are thus reduced or removed the collateral effects of such leads and connections one upon the other with the further and important result of entirely eliminating many of the common causes and minimizing other causes of harmful feed back effects.

A further objectfand achievement of the present invention is to enable the use of mathemati-- cal precision and measurement to calculate and determine the effects of changes and variations in radio apparatus design and construction, or the like, by placing directly across the battery or other current supply circuit and other circuits a high capacity condenser the capacity and impedance values of which are definitely known and remain fixed.

A further object of invention is to enable the use of modern production methods in the manufacture of radio and other electrical apparatus thus insuring duplication and identity of results 40 by providing for connection of instruments and parts without the use of wires by the use of conveniently located taps arranged in predetermined grouped relation at convenient intervals.

A further object of invention is to provide an improved assembly unit by which capacity and impedance effect may be ascertained and controlled and in which these effects may be varied at will by utilizing the grouped conductors in difr ferent sequence or relationship, and by providing ,a such conductor strips in different numbers, thus allowing .a choice of widely or closely spaced individual strips for specific purposes with corresponding variations of. capacity and impedance effect. i a

A further object of invention is to provide such approved form of distributor-condenser capable of production in stock lengths to be subsequently cut to size as needed, or to be formed in sections or units to be joined one to another to afford a distributor-condenser element of required size.

With the above primary and other incidental objects in view as will more fullyd appear in the specification, the invention consists of the features of construction, the parts and combinations thereof a'nd the mode of operation, or their equivalents as hereinafter described and set forth in the claims.

Referring to the accompanying drawings wherein is shown the preferred but obviously not necessarily the only form of embodiment of the invention, Fig. 1 is a perspective view of a simplified form of the assembled distributor-condenser or by-pass strip forming the subject hereof. Fig. 2 is a detail perspective view showing a portion of the strip shown in Fig. l separated into its component parts. Fig. 3 is a plan View somewhat diagrammatic showing the assembly of a radio receiving set utilizing the present distributor-condenser unit for interconnecting the several parts.

Fig. 4 is a plan view of the conductor-condenser strip in a form for commercial production. A series of sockets, a potentiometer, rheostat, resistance unit, transformers, and phone jack, have been shown interconnected by the distributor-condenser device.

Fig. 5 is a plan view of one of the individual strips. Fig. 6 illustrates the use of the device in conjunction with variable condenser plates. Fig. 7 is an enlarged transverse sectional view. Fig. 8 is a detail plan view partly broken away. Figs. 9, 10 and 11 illustrate different sequence or combinations in which the conductors may be employed.

Like parts are indicated by similar characters of reference throughout the several views.

While regeneration or feed back is quite a desirable factor in some forms of radio apparatus if properly controlled, but the promiscuous "feed back or transfer of electrical energy from one part of the circuit or apparatus to another is the cause of much inefficiency, distortion, and undesirable operation of radio apparatus. It is almost impossible to determine the inter-capacity eifects of numerous small wire connections of the radio apparatus many of which extend parallel to each other and within the fields of condensers and transformers and the impedance effect of long leads, soldered joints, or loose connections. It is to overcome this unknown factor which differs materially in every set or apparatus although apparently constructed according to the same plan; and in order that these capacity and impedance factors may be reduced to measurable values and maintained in certain known limits, and objectionable feed back effects or transfer of energy from one part to another minimized, that the present form of distributor-condenser unit has been developed.

In the present device there is contemplated a simple eiicient group connector having definitely known capacity and impedance factors, which will be mechanically strong and rugged to withstand shipping, handling and hard usage, and which will possess a neat appearance and afford a safe guard against mistakes in wiring and accidental short circuits withv their incidental destruction and injury to tubes and batteries and which will further more possess a wide degree of adaptability to a large number of different circuits and forms of apparatus. Considered electrically the device is designed to diminish inductance in the battery circuits and hence the creation of less external fields, and less radio frequency activity across leads and between parts of the apparatus. The by-pass effect afforded by the increased capacity lowers the radio frequency voltage and eliminates much objectionable feed back or undesirable transfer of energy. The reduction of external fields minimizes the ability to pick up radio frequency energy from adjacent apparatus and thereby eliminate much interference.

The distributor-condenser strip or element forming the subject matter hereof comprises a series of independent strips I 2, 3, 4, and 5 of electroconductive material superposed one upon the other in parallel spaced relation and separated by intermediate strata 6 of dielectric or insulating material. There may be any number of such superposed strips incorporated in a distributor-condenser unit. Some of these strips subsequently may be connected in pairs by the constructor to increase capacity effects or intermediate strips may be grounded to eliminate capacity effects. The series of conductive strips I to 5 inclusive are of identical construction and are provided at spaced intervals with marginal tabs or ears l. Although in Figs. 1 to 3 the tabs or ears l are located on one margin only of each strip, for commercial production they are preferably duplicated on opposite margins of the strips as shown in Figs. 4 and 5. serve as tabs or outlets for electrically connecting the conductor strip with various instruments or devices. To facilitate the assembly of the series of such strips and to more securely embed them in a body of insulating material, the strips are preferably perforated at spaced intervals as at 8, through which the succeeding strata of insulating material join as at 9. These perforations also facilitate the assembly of the strips with their lateral tabs or ears 1 arranged in predetermined spaced sequence. This is effected by off-setting the strips longitudinally so that the perforation 8a of one strip will register with the perforationv 8b of the next strip and 8c of the succeeding strip, etc., thus stepping `the tabs l of each succeeding strip longitudinally one space. The succeeding ears orv tabs on the individual strips are spaced sufficiently far apart to afford an intermediate space between each group of spaced tabs of the assembly. In the commercial product this space between groups substantially agrees with the distance between the connections of the regulation or standard tube socket and other apparatus. If only a single series of ears or tabs T are provided the strips are alternated or part of them turned one way and part the other so that their tabs l extend in opposite directions and will project from opposite margins of the finished distributorcondenser strip or element l0. While the several strips l to 5 are duplicates of each other, due to their assembly in longitudinally offset relation to each other, the tabs or outlet connection 1 on 'opposite sides of the assembly are spaced in predetermined sequence. The sequence of spaced tabs 'l pertaining to the different conductor strips is successively repeated throughout the length of the distributor-condenser element. Since each conductor strip is provided with a plurality of tabs or outlet connections 1 and the tabs or outlet connections of different strips are grouped in Such tabs or ears 'l 'spaced sequence all of such conductor strips are i conveniently available for connection of instruments and devices at any point throughout the will employ for a specic purpose. It is found most convenient to employ thetwo strips having their tabs or outlet connections 1 turned toward the same side in alternating'spaced relation. in Figs. l to 3 for the filament circuit or A+ and A- battery connections. -At the same time the strips e having their tabs or outlet connections 'I turned in the opposite direction in Figs. l to 3 and exposed .in spaced sequence are employed for the B+45 and B+90and C battery connections.

In the commercial form of the device illustrated in Fig. 4 it has been found most convenient to utilize the rst and last tab or ear I of each group as the A+ and A-; connections for the tube lament. The intermediate tabs lof each group are employed for the B+ and C battery connections. It is unnecessary to provide a special conductor in the unit for the B- connections since in any event such connections ultimately lead to the A- conductor. Since it is customary to use different B battery voltages as B+221/2 B 45, andr B 90, such individual conductor-strips to be utilized for B battery circuits may be arranged with their tabs or ears I in registery or one directly above the other, in order to economize space and provide for the repetition of the groups of connections at more frequent intervals. In the event only one' of the B+ ears or tabs I will be util-ized 'ata given taining to the B battery conductors, which are found unnecessary ata given point, may be readily removed. The material being quite thin such protruding ears are easily clipped or torn off thus leaving only the particular B+ tab or ear 'I to be utilized.

As before mentioned andas shown in Fig. 4 the successive groups of outlet tabs I are duplicated upon the opposite margins of the distributor-condenser unit I0. This not only enables the convenient connection of instruments or parts located on either side of the distributor-condenser strip III but it also accommodates instruments or parts of various sizes which may overlap the distributor-condenser strip to greater or less extent. In addition to facilitating the connection of instruments or parts at widely spaced opposite points such instruments or parts may be connected at points intermediate the ears 1 by bending such ears .backwardly over the top of the insulating body. To this end the unit or strip I Il is provided at spaced intervals .with holes I I. These holes II are concentric with the perforations 8 of the several conductor strips I, 2, 3, 4,

and 5. The holes I1, however, are contained only in the. insulation or dielectric material protruding through the perforations 8 of the several strips and serving to join the strata of dielectric or insulating material one to the other. This relation of the hole II surrounded by a body of insulating material within the perforations 8 of the several strips is illustrated in Fig. 8, and in transverse sectional view in Fig. 7. The tab or ear 1 which is vbent reverselyover the body of the distributor-condenser unit is secured in its reversed position by a rivet or bolt I2` inserted through the hole I I and through the perforation in theear or lug 1. This bolt or rivet I2 may' also serve to connect an instrument or a binding post for a lead or conductor extending to suchinstrument. these outlet connections 'I for instruments of different sizes is illustrated in Fig. 4 wherein are shown three different sizes of transformers. transformer I3 is of comparatively large size and 'extends across the distributor' condenser unit and connects with the B+ and C tabs or ears I at the far side of the strip or unt I0. The opposite end of the primary coil of the transformer is connected to the plate terminal of the tube socket I6. The opposite end of the secondary coil of the transformer is connected to the grid terminal of the succeeding tube socket IS. Thus by-locating the 'transformers and tube sockets alternately or with the transformer immediately disposed between successive tube sockets the transformercoils may be directly connected at one end of the plate and grid terminals of the successive sockets While the opposite ends of such coils are directly connected to the proper outlet tabs I of the distributor condenser unit.

YAt I5 in Fig. 4 is shown a small size transformer which is likewise connected with the grid and plate terminals of successive sockets, the opposite ends of 4such coil being directly connected with the B+ and C terminals .l upon the near or adjacent margin of the distributor-condenser unit strip I Il. Intermediate these two 'transformers I3 and I5 is shown a third transformer I4 of an intermediate size. The B+ and C terminals of .this transformer extends too far over the distributor-conductor strip for direct connection with the tabs upon the near or adjacent margin as the transformer I5 is connected and they do not extend far enough for direct connection with the tabs at the far or extreme margin of the distributor-conductor strip I0 like the transformer I3. For the convenient direct connection of the transformercoils I4 with the distributor-conductor strip III the B+ and C tab or ear 1 are reversely bent over the top of the strip I0 and secured in such reversed position by the bolt or rivet I2 extending through the holes II which bolt or rivet may also serve to connect the end of the coils of the transformer I4. Thus various instruments may be conveniently connected either on the medial lines of the distributor-condenser strip III or beyond the opposite margins of such strip. There is shown at I1 in Fig. 4 a typical form of fixed resistance unit I'I which is extended transversely of the distributor-condenser The The manner of utilizing unit or strip I0 and is connected to the A- ear or tab 1 at one side of such tab and to the F- terminal of the tube socket IB at the opposite side of the strip. In rsuch case the A-` tab or ear on the margin of distributor-condenser unit or strip I0 adjacent to the F- terminal of the socket will be torn off or removed. This is also the case at I9 in Fig, 4 where the A- tab or ear has been torn off or removed and the lament terminal of the tube socket I6 is connected by a short lead 20 with the rheostat 2I the opposite side of which is connected with the adjacent A- tab on the strip or unit ID. The phone jack 22 is connected directly to the B+ tab while the sleeve portion of the jack is connected to the plate terminal of the last socket of the series. L kewise in connecting a potentiometer as shown at 23 in Fig. 4 one terminal of the potentiometer is connected to the A+ and another to the A- tab of the distribuor-condenser strip or unit I0 while .the intermediate terminal 24 of the potentiometer `may be connected to a tab or ear upon a strip within the unit II) to which is connected the grid returns from transformers, etc. It is entirely optional with the constructor of a radio apparatus which of the superposed strips he will use for a particular circuit or purpose. For convenience of assembly the tabs 'l may be perforated for direct connection with the binding posts of tube sockets, transformers, rheostats and the like or such tabs may be utilized as solder connections for connecting the various instruments and devices into the circuit. The constantly re-occurring tabs or outlet connections 1 on each conductor enable the direct connection of the various instruments and devices with minimum lengths of leads. It has been found possible and practical by use of this distributor-condenser strip to build typical receivers of various types without the use of connecting wires or leads by direct connection of thekinstruments with the tabs '1. A typical method of using the distributor-condenser unit heretofore described for the interconnection of the principal parts of a radio apparatus is illustrated in Fig. 3. A most convenient method of assembly is to mount the various instruments such as the tubes or thermionic valves, transformers and inductance coils, resistant elements and the like upon a base or sub-panel and to mount the distributor condenser unit herein described on the under side of such sub-panel connecting it through the subpanel to the instruments above. Some of the instruments and devices, however, may be atfached to the under side of the sub-panel overlying the distributor-condenser unit, which as before described is completely insulated except the outstanding tabs or outlet connections 1.

The judicious variation of the sequence in which the individual conductor strips are utilized affords a wide variety of effects. By adopting different conductor strips l to 5 for A and B battery circuits various capacities and impedance effects can be thus achieved. The conductor strips for A and B battery purposes in the succession or relationship shown diagrammatically in Fig. 9 the A- conductor strip would have but little or no capacity effect upon the B 45 conductor. If, however, this selection is made as indicated diagrammatically in Fig. 10 there would be an increased capacity effect between the A- and B+ conductor. By providing additional or surplus interposed conductor strips and interconnecting strips in multiple as shown diagrammatically in Fig. 11 a maximum intercapacity effect can be secured or conversely by leaving certain intermediate conductor strips disconnected and un-I used thereby increasing the spacing between active conductor strips or by grounding such intermediate conductor strip the intercapacity effect may be eliminated. The various capacity effects and conversely the impedance of the distributor-condenser element may be further varied by making the conductor strips I to 5 of greater or less width, and as well of greater or less length. Instead of being strips these members for special electrical effects and to meet certain conditions of usage, may be formed as superposed plates. Such plates may be used as conductors for interconnecting various instruments or parts while at the same time the capacity effect may be increased and impedance decreased. Thus the element possesses the material advantage that value of the capacity and impedance factor can be accurately and mathematically ascertained and be predetermined by such variations of size and of selection of the conductor members for particular purposes whereby certain selected conductors may be more or less closely related in their assembly. 'I'he superposed closely spaced relation of the individual conductor strips embodied in the distributor-condenser unit enables one strip to shield the other, thereby preventing the creation of an external field and the elimination of pickup and radiating characteristics. This series of iiat spaced strips confined in a small space is unable to cut many lines of force and the fields therebetween are concentrated with no opportunity to radiate lines of force. Consequently no inductive pickup and throw-ofi` effect occurs.

'Ihe distributor condenser unit herein described may form a part of the shielding of a radio set in addition to its other functions.

In addition to its function as a distributor for current, a by-pass condenser for high frequency current and elimination of undesirable feed back effect, and for shielding purposes, the unit strip IU herein described may further form one part or element of a series variable condenser for tuning purposes. In all or nearly all radio sets one element or group of condenser plates as the case may be is grounded or connected ultimately through various leads to the A- conductor. In the presentcase such A- conductor strip embedded in the unit may itself become such variable condenser grounded element and may furthermore be common to a plurality of variable elements. Such a construction has been shown more or less diagrammatically in Fig. 6 wherein are shown the fixed conductor strips I, 2, 3, 4 and 5 comprising the distributor-condenser unit I0 heretofore described. Associated with this distributor-condenser unit I0 are a plurality of movable plates which are arranged for capacity effect with the unit I 0. These plates 25 may be variously adjustable. In Fig. 3 two of the plates 25 are shown mounted for parallel movement in a plane closely adjacent to and parallel with the unit strip l0. In Fig. 6 the several plates 25 are shown as capable of oscillatory movement toward and from the unit strip I0 thus affording a series of book type variable condensers. The variable plates 25 may be connected into different circuits as is shown in Fig. 3. However, the distributor condenser unit Ill is common to all of these condenser plates 25 which may be interconnected for unison adjustment or be independently adjustable. Thus the distributor-condenser unit I0 eliminates entirely the wiring connections to one side of the series of variable condensers, and results in greatly confining the fields surrounding such condensers.

The term battery currents herein mentioned is to be construed as meaning supply for filament, anode' and grid biasing purposes from whatever source, whether battery, power lines, or other source and is not limited to battery sources alone. The terms A battery, B battery and C battery re used merely for illustrative purposes and to agree with general usage, but with no intention to limit the application or scope of the invention. These terms are to be construed as including the use of battery eliminators and other direct sources of current supply other than batteries.

Duo-functional condenser conductor unit or a duo-functional connector is used in the claims to designate an element used for conducting an electric current from one portion of a circut to another wherein the current fiows through the element and where the same element cooperates with another element in intercapacity relation so as to form a condenser wherein the charges accumulated are utilized for a beneficial purpose. In the modification disclosed an element has been used for supplying current to the several filaments in one circuit and at the same time cooperating with a like element in another circuit to form a condenser which functions as a by-passyfrom one circuit to another. The element may, for example, supply the filament koi! the two with direct current, a low frequency undulating current or a low frequency alternating current andat the same time cooperate with another elementin a plate circuit to form a by-pass condenser for "the high frequency currents from plate to filament.

From the above description it will be apparent that there is thus provided a devicel of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously issusceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in orderto comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific details shown, but that the means and construction herein `disclosed comprises the preferred form of several modes of putting the invention into effect and the invention is, therefore, claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my invention, I claim:-

l. As an article of manufacture an electrical distributor-condenser unit comprising a bodyof dielectric material, a plurality of fiat strips of electroconductive material embedded therein in parallel spaced relation, and a succession of spaced outlet taps on each of said strips extending laterally beyond the enclosing -body of dielectric material at intervals throughout its length.

2. As an article of manufacture, an electrical distributor-condenser unit comprising a plurality of independent electrical conductors assembled in parallel spaced relation, and a succession of spaced outlet taps on each conductor by which the conductors may be connected into independent circuits at convenient points, said conductors having an intercapacity effect between adjacent conductors of the assembly, but normally lacking direct connection with each other.

3` As an article of manufacture an electrical distributor-condenser unit comprising a plurality of independent ribbon-like electrical conductors pertaining to different electrical circuits having independent sources of electrical energy inseparably arranged in fixed parallel spaced relation, said conductors having a large area so as to have a predetermined intercapacity effect and a succession of integral outlet taps on each conductor, said outlet taps pertaining to different conductors being arranged in grouped relation.

4. As an article of manufacture an electrical` l distributor condenser unit comprising a body of dielectric material, as series of flat electroconductive strips embodied therein, a succession of outlet` taps extending from each strip beyond the. enclosing body of dielectric material, the outlet taps pertaining to different strips being arranged in grouped sequence repeated at intervals throughout the length of the unit.

6. As an article of manufacture an electrical distributor condenser unit comprising abody of dielectric material, a series of flat electroconductive strips having useful intercapacity effect, said strips being imbedded in said dielectric material. a succession of outlet taps carried by each of the strips, the outlet taps of different strips being extended in different directions beyond the encloscondenser common to the positive and negative leads of both the 'filament and plate circuits.

9. In a radio apparatus, including independent sources of electrical energy for different circuits and a series of fiat electroconductive strips arranged in inherent electrostatic relation with each other, said inherent electrostatic' relation being utilized as a by-pass circuit for alternating components of the currents carried by said circuits, the positive and negative leads of eachof the circuits having one of said strips included therein and forming a continuous connecting part of the current lead thereof.

10. In a radio apparatus a series of instruments and parts to be interconnected, a distribu tor unit common to the series of instruments and parts, said unit including a plurality of electroconductors pertaining to different circuits arranged in parallel spaced relation, and a plurality of outlet taps carried by each conductor at spaced intervals whereby one of said outlet taps will be conveniently located in proximity to each of the instruments and parts to be connected thereto, said electroconductors being arranged to afford an intercapacity andelectrical by-pass effect between the several circuits.

1l. In a radio apparatus, a series of instruments and parts to be interconnected, a duo-functional condenser conductor unit common to the series of instruments and parts, and comprising a series of electrical conductor elements arranged in fixed closely' spaced relation to afford an intercapacity effect therebetween and means at spaced intervals intermediate the ends of each conductor for connecting instruments and parts at alternate points tov each of the several elements of said connector-condenser which comprise component parts-oi different electrical circuits.

l2. As an article of manufacture, an electrical distributor unit comprising a series of independent electrical conductors arranged inan intercapacity relationship with each other and encased in a body of phenolic condensation material, each conductor having thereon a succession of exposed spaced taps wholly independentI of and separate from the other conductors of the series by which instruments and Vparts may be connected- Ato anyone or another selected conductor at different points throughout the lengthmf the unit,

said intercapacity relationship of the conductors being utilized as a by-pass circuit from one conductor to the other.

13. In a construction of the character described, the combination with a plurality of relatively fixed electrical conductors forming component parts of diilerent electrical circuits having independent sources of electrical energy independently connected with different parts of a radio apparatus, said conductors being so located as to have intercapacity effect upon each other i of a movable condenser element adjustable relative to said relatively fixed conductors to vary the capacitive effect therebetween.

14. In a construction of the character described a plurality of independent electrocon duotors comprising component parts of different electrical circuits having independent sources of electrical energy, and connected with different parts of a radio apparatus and arranged in grouped relation so as to have intercapacity effect upon one another, and a relatively movable element having variable capacity relation with said grouped conductors.

15. In a construction of the character described, a plurality of fixed condenser elements,y i and a plurality of variable condenser elements associated in capacitive relation therewith to which the fixed elements are common, different members of said plurality of variable condenser elements being connected in different electrical circuits having independent sources of electrical energy.

16. In a construction of the characterdescribed, a plurality of relative iixed continuous electrical connectors forming component parts of different electrical circuits having independent sources of electrical energy, and a plurality of adjustable condenser elements located in circuits dierent from said continuous electrical connectors and variable relative to the connectors with which they have capacitive relation and which are common thereto.

1'7. In a construction of the character described, a plurality of electrical circuits, a plurality of adjustable condenser elements separately included in different electrical circuits and a continuous electrical connector included in a circuit other than those containing said condenser elements common to all the adjustable condenser elements and having capacitive relation therewith but negligible mutual inductive coupling.

18. In a construction of the character described, a plurality of electrical circuits, a plurality of swinging condenser plates and a continuous electrical connector strip included in different electrical circuits having independent sources of electrical energy, said strip being common to all the plates and with which the plates have capacitive relation toward and from which the plates are swingingly adjustable to vary the capacitive relation therebetween, said strip having negligible mutual inductive coupling with the plates.

19. In a construction of the character described, a group of electrical conductors arranged in capacitive relation with each other, different electrical conductors comprising line connections in diiierent electrical circuits, having independent sources of electrical energy, and a series of adjustable condenser elements included in electrical circuits other than those containing the said conductors and arranged in capacitive relation with the said electrical conductors, said group of conductor elements being common to all said condenser elements.

20. As an article of manufacture, an electrical distributor-condenser unit comprising a body of dielectric material, a plurality of strips of electroconductive sheet material embedded therein in parallel spaced relation, and a succession of spaced outlet terminals on each of said strips extending to the exterior of the dielectric material at intervals throughout its length.

21. As an article of' manufacture, an electric distributor-condenser unit comprising a plurality of independent electrical conductors assembled in spaced relation and a succession of spaced portions on each conductor, said spaced portions being accessible from the exterior of the assembly whereby the conductors may be connected into independent circuits at convenient points, said conductors having an intercapacity effect between adjacent conductors of the assembly but normally lacking direct connection with each other.

22. In a radio receiver for a multi-element tube, an electro-conductive condenser unit including a ground strip, a plurality of ribbon-like strips arranged in intercapacity relation with respect to said ground strip and separated therefrom by insulating material holding the strips in fixed relation, means for connecting said ribbon-like strips to the elements of said tube, portions of said strips being accessible for connecting the elements of the tube to their respective circuits through said strips, whereby the ribbon-like strips are connected to a plurality of said tube element circuits in which circuits said ribbon-like strips form uninterrupted line connections.

EDMUND T. FLEWELLING.

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